Kinetico Low Salt Alert

Being a new water softener user, (March 2021), I was constantly checking the level of the block salt my Kinetico Premier Compact uses and as my unit is outside due to space restrictions, I thought there must be away to remotely alert if more salt was required.

I have used Sonoff Smart devices for a number of years which are monitored and controlled via the eWeLink App on my iphone and ipad so I knew this was the non invasive way to go, especially as the DW2 battery level and online status is monitored and alerted on the App .

Caution – The method I’m using is not fail safe, please don’t blame me if your water reverts back to being hard because you ran out of salt :-).

Ok, now that’s out of the way, the method I thought I would try involves modifying a Sonoff DW2 -WiFi wireless Door/Window Sensor, the modification would be to change the original Reed Switch which is normally kept closed and out of an alert condition by the presence of a magnet, I needed the opposite of this, the introduction of a magnet would cause an alert.

The idea is that a strong magnet will sit on top of the left hand salt block as this was observed to be lagging the right hand one, as the block dissolves (14.64mm per day based on a 14 day period), the magnet carrier will fall, eventually reaching a point at which it will trigger the sensor which is on the outside of the water softener, this will then alert via the eWeLink mobile App as below.

So to the shopping list, all of eBay:

Version 1 – Scroll Down for improved revisions

  • ABS Box (75.5 x 49.5 x 28) @ £4.50,
  • Disk ring Neodymium magnet 20 x 4mm @ £4.89 for two,
  • Reed Switch 3 pin magnetic switch normally open closed conversion 2.5 x 14mm @ £4.79 for five,
  • Sonoff DW2 – WiFi Door/Window Sensor Smart Switch @ £8.15,
  • AAA batteries x2 (already had),
  • Piece of Velcro sticky back Hook & Loop,
  • Glue CT1 (already had),
  • (Version 2) offcut of 22mm and 20mm plastic conduit (already had).

Parts came to ~£23.00

Version 1 – First job was to glue the disc magnet inside the ABS box, after trail and error, the best place for the magnet was the rear left side of the box.

Next task was to remove the reed switch which comes with the DW2, this is easily identified as the long thin black rectangular component on the same side as the battery clips, this simply unsolders from the PCB pads.

The PCB is held in place by a small blob of white silicon at each end and a clip, using a small screwdriver to carefully prise the board out does the trick.

I originally soldered the normally closed reed switch in the same places as the original, but I thought I needed to get the reed switch as close as I could to the wall of the softener, so I used the Sonoff’s magnet enclosure to hold the normally closed reed switch after attaching so flying leads.

The image below shows the type of reed switch I needed to fit as I had to change the reed to be normally closed without the presence of a magnet, telling the DW2 door sensor that the door was closed, when a magnet is introduced, the reed moves position within the glass envelope, breaking the circuit, triggering the DW2 to alert to a door open which in our case is low salt level.

Reed Switch Operation | Reed Switch Developments Corp

The base of the magnet was attached to the transmitter by the supplied adhesive pad.

A couple of holes were drilled and the wires from the reed switch were soldered to the PCB pads.

Once the eWeLink App is downloaded and an account is created (can be free but I chose to pay the nominal fee), the DW2 can be paired on the 2.4GHz WiFi home network, this is incredibly easy, open the app, press and hold for 5 seconds the push switch on the DW2 until a red LED flashes, back on the App – Press add device and after entering your WiFi details, the DW2 is paired 🙂

Details can be configured in the App, including changing the alert description, push notification and sharing the alerts with other eWeLink accounts if needed.

Now the moment of truth – bringing the magnet close to the reed switch should trigger the App status to show the switch is open and change to closed when the magnet is moved away.

As my block salt level was low, I noticed that the blocks tilts back slightly in use, I put the ABS box on top of the left hand block and due to the lean it should stay in the same place on the block as it drops.

I offered up the DW2 to the outside of the softener while watching the App status, moving it up and down the outside of the unit until it triggered, I marked with a pencil using the top of the DW2 on the cabinet the point at which I wanted an alert, I then stuck a strip of self adhesive Velco hoops under the pencil line.

The magnet I used is deliberately powerful, and it was no surprise that it operated the reed switch when it was some distance away from the reed switch and will continue to hold the reed switch open for a fair bit of travel as the salt level lowers, this was factored during the setup process.

Using Velco I secured the DW2 to the softener as this allows for fine adjustments and the job is done.

Salt changed and system ready with room for the lid.

This was the first time I had replaced the blocks and those with keen eyesight will note the blocks are not installed as per the manual (page 18), this has now been rectified.

Version 2 – Magnet Carrier

A few days after changing the block salt, I decided to see how the ABS box magnet carrier was sitting on top of the salt …………disaster!

As you can see from the picture, the left hand salt block has leaned over to the right taking the magnet too far away from the side wall, it may well be that when the salt block drops it may once again move to the optimal position for the magnet, I didn’t want to take the chance, so here is Version 2 which will defiantly need further revisions.

I took the two magnets out of the ABS box and cut two pieces of plastic conduit, the 25mm conduit spans the salt block gap, with a shorter piece of 20mm conduit glued inside it, the magnet was glued inside the 25mm pipe with the 20mm pipe acting as a backstop.

It was important that the magnet was flush with the end of the pipe as I’ve ordered some plastic end caps as I don’t want any metal contact with the salt or brine solution.

Its quite hard to see, but the conduit pipe bridges both salt blocks, I put a magnet at each end so it wasn’t important which way round I put it in.

The major problem with this design is that the pipe will hit the salt grid which I have only just noticed, so watch this space!

Version 3

To address the problems with Version 2, I bought a piece of 3mm thick Perspex and cut it to act as a full height guide for the left and salt block, the guide simply rests against the salt and the existing salt grid assembly.

I cutdown the magnet tube holder to be a nice fit and this time I’m only using one magnet to bias rather than trying to balance the tube.

Lessons Identified

1 . Make sure you have a solid WiFi signal where the DW2 is fitted.

The eWeLink App shows signal strength that the DW2 is seeing, however, once I put the box around the softener, the received signal strength fell and the DW2 went offline. To resolve this I changed one of the kitchen sockets, which is near to the softener, to a WiFi extending version from Screwfix (988FV) and this worked fine.

2 . The DW2 eWeLink allows for a selectable Push Notification to your phone if the switch either opens or closes, I could have left the DW2 as it arrived out of the box and made the change in the App rather than physically modify the DW2.

3 . My salt level was falling at a rate of 14.6mm per day and we will always have 8Kg available (Block 280mm tall/14.6mm daily usage = 19 days per 8Kg). This was the first salt the softener had used, so it may slow down, the point being to set the alert level to suit adding a new block straight away, or as a trigger to re-order or change it in X days, the positioning of the DW2 determines the alert trigger.

You could always add another DW2 using the same magnet, with one DW2 set as a pre-salt order trigger with the other DW2 as the block change alert.

4 . The ABS box for the magnet was just the right size, if it was any larger it might not allow the lid to close in the salt compartment when a new block was fitted, but it was small enough to give me an alert on low salt level with 30mm salt left (day and halfs worth).

5 . Keep an eye on things in case they don’t go to plan, hence Version 2 🙂

What’s Next

I’ve ordered another DW2 to see if it will work ok without any modifications, the other thing I’ve done is link a light controlled by a Sonoff Basic switch to the existing DW2 smart switch status, Low salt = light ON, all this is done via the eWeLink App and works great.

Kinetico Water Softener

We moved from the North a number of years ago from a soft water area to Chatteris, Cambridgeshire which has water classified as Hard, the effect of this is that soap doesn’t lather easily and appliance heating elements get coated in limescale reducing efficiency and life.

As a home improvement project, I decided to research water softeners.

How is Hard Water Quantified
Parts Per Million (ppm)

This scale is used to measure very small amounts of something in a larger quantity of liquid. It is used to measure dilute concentrations of chemical substances. One litre of water weight 1 million milligrams (mg). So 1 part per million (ppm) would mean the chemical is one millionth of the solution, or 1mg per litre. 

For water hardness levels, we measure parts per million of minerals including calcium carbonate (CACO3) in the water. Calcium carbonate is the compound in hard water that causes limescale build-up. Soft water typically has less than 50 ppm of calcium carbonate. Hard water has over 200ppm, Anglia Water drinking water quality information for the Chatteris area shows that the level is 230ppm compared to where we used to live which was 17.5ppm. 

I bought a water hardness test kit from Toolstation and this indicated that my incoming cold water was between 240ppm ~ 280ppm so I know the extent of the hardness which be of use later.

1 drop of reagent into incoming hard water , adding drops until the solution turns blue
After 12 drops equates to 240ppm on the 1 April 21, the same test on the 22 February 21 came out at 280ppm.
Water Softeners

These work by ion exchange, incoming hard water passes through a bed of activated resin beads, these beads remove the calcium carbonate and magnesium molecules as the water passes through the resin chamber, the exiting water is now free of the limescale causing molecules and is now soft.

To maintain the resins ability to ion exchange the resin is backflushed with a brine solution, the backflush waste water goes directly to drain.

There are a number of considerations to take into account in selecting a water softener, these are:

  • Cost to purchase
  • Cost to run
  • Salt – Block or Granular
  • Number of bathrooms
  • Number of people living in the property
  • Incoming water pressure
  • Single or Two resin chambers
  • Type of hot water system (Gravity, Indirect or combi boiler)
  • Electrical supply required or not
  • Physical size of the softener and where will it go
  • Warranty
  • Dealers
Cut away view of of Kinetico premier compact
What did we choose and why

I’m definitely no expert on water softeners, first port of call was the internet and YouTube to see what were the popular UK models and to read reviews that users made on dealer sites.

Going through the above list, the purchase and running cost will be known after most of the other points are answered.

3 live in the property and we have 2 bathrooms (ensuite shower is classed as a bathroom), the hot water is supplied from an unvented indirect cylinder, meaning the hot water is under a constant pressure and pushed out of the cylinder to the hot tap by the incoming water pressure at the bottom of the cylinder, the incoming pressure is typically maintained at 3 bar so that the hot & cold taps and mixer showers for example are at the same pressure.

Where the hot water uses the incoming water pressure, a High Flow (HF) unit will be required as the flow rate is higher through the resin chambers to reduce any pressure drops, also the softener inlet and outlet pipes are larger.

If the water pressure to the house was low, introducing the water softener might cause a problem, I measured the pressure here at 2.8 bar (40psi) which is fine, a pressure gauge is available from Toolstation.

The activated resin chamber I mentioned earlier needs to be regenerated, (back flushing the beads with brine (salt solution)), with a single chamber, softened water will not be available during the regeneration process, we opted for a dual chamber unit so we always have a supply of softened water, however this does have a cost implication.

How does the softener know it needs to be regenerated?

Two methods, timed or metered. With a timed version, an electrically powered (low voltage via a transformer) timer will trigger the process, the main disadvantage apart from requiring a power source is that regeneration could occur if no softened water was used, but simply based on time.

A strong advantage of an electrically powered softener is the ability to have an alarm indication on low salt, with a mechanical only unit, you have to physically monitor this (but I’m working on it 🙂).

The softener we selected used actual metered soft water usage to mechanically trigger regeneration

The model which satisfied all our requirements including a 10 year warranty was the Kinetico Premier Compact HF which we bought from Aquastream Water Softeners Ltd who gave exceptional service, they responded to my emails quickly and are experts in their field, I would not hesitate in highly recommending them.


If you are a confident at DIY, the plumbing for the water softener is very easy, with only two pipes and a drain hose, the price of the softener included the 22mm Bypass kit which contains all the full bore valves, strainers and 0.75m flexible hoses to connect the houses fixed plumbing to the softener.

Due to the underneath of the kitchen sink base unit being full of other stuff, we decided to put the unit outside and to build a wooden insulated enclosure for it.

As we replaced the kitchen a few years ago, I knew where the incoming water pipes run, from the picture below you can see the rising main and stop cock, this tees off for the kitchen sink, with the 22mm copper pipe transitioning to John Guest 22mm push fit disappearing behind the dot & dab plaster boarded wall on its way to upstairs.

The kitchen base cabinets were a bit too ‘busy’ for the softener to fit but left enough room for me to access the buried pipes once a hole is made in the cabinet back .

Once the cabinets back was cut out and plasterboard removed to expose the 22mm plastic cold water pipe, two 32mm holes were drilled to outside, the holes then sleeved with 28mm copper pipes ready for the 22mm copper passing through these to outside.

The water supply to the Insinkerator hot water boiler is from the valve on the left of the picture, the boiler water feed will be moved from hard to soft.

It is important to keep the kitchen sink cold tap feed before the water softener for cooking and untreated drinking water, it is also advisable to supply any outside taps before the softener to save on salt usage and prevent damage plants over time.

I used ‘O’ rings around the 22mm pipes to keep them centralized within the through wall sleeves.

To make the plastic pipe to fitting connection, it is important to cut plastic pipe to leave a clean cut and to use superseal pipe inserts, marking the depth of the fitting on the pipe before pushing it onto the pipe ensures that it is fully seated.

The pipe cutter I used came from Lidl and cost £5.99

Lidl  Parkside Pipe Tools

On the John Guest pipe their are fitting engagement marks already made to assist with ensuring the fitting is fully pushed over the pipe, but my fittings didn’t marry up with these, so I measured and marked the pipe to confirm the elbow and Tee were fully engaged before pushing them home and tightening the collet ring after which I pushed on the locking rings (Blue clips).

The 15mm copper pipe leaving the Tee in the picture below, is the new softened water supply to the hot water boiler, all the copper elbows (15mm for the water boiler and 22mm for the softener) are long street elbows, this reduces joints and saves space which was ideal in my situation.

To keep everything in place and to insulate the pipes I used expanding foam, two other pipes are in the picture, one is for the outside taps which I lagged internally when the kitchen was being fitted, the other is another plastic pipe, this time 15mm for the kitchen sinks hot water tap.

With the cover on, nobody would know the carnage 🙂

On the outside the bypass valves and copper runoff to drain installed.

The copper pipe is the regeneration drain for when the resin chambers are back flushed and must be air gapped from the waste system to avoid any cross contamination with the drinking water. The cold water inlet to the softener must have a a non return valve to prevent back flow.

Finished installation, the Kinetico softener is off the ground sitting on a 50mm polystyrene backed base, 22mm stainless steel braided hoses each have a strainer fitted and to ensure that the softener doesn’t freeze, I have taken the precaution of installing a 40 Watt thermostatically controlled tube heater from Toolstation.

Easily removeable frame, sides and top lined with 50mm polystyrene, access for checking salt is by lifting the top off.

Schematic for planning valves and documenting modifications
Running Costs

The cost of the softener including bypass valve arrangement and 2 x 8Kg blocks of salt including factory setup was £1,295.00 inc VAT which was as cheap as I could find.

The only consumable other than regeneration water is Kinetico Block salt, the cost varies tremendously and I have found Saltstore to be the most competitive with an excellent online ordering system and friendly staff.

I have mentioned water hardness and the metered chamber regenerations, the Kinetico uses different metering disc types in their machines depending on water hardness, this directly impacts on the number of regenerations.

For my areas water hardness a Type 6 disc, which regulates regeneration frequency based on flow through the softener, is installed, therefore after 327 litres of softened water has passed through the resin bed, the cylinder will regenerate using 20.5 litres of water and 0.34Kg of salt.

After referring to the specification table, I did query with Aquastream Water Softeners the reason for supplying a Type 6 disk with my softener as this is for up to 362ppm and in my area the maximum I have measured was 280ppm which would be within the scope of a Type 5 disc (305ppm).

The answer was based on their experience and knowledge in that the table values are factory test bench conditions and not real world, the water in Chatteris is typically around 300ppm and very low flow through the softener would not be metered, therefore their is a risk that we could have hard water before the softener regenerated which made perfect sense. Good to know.

The following spreadsheet shows expected costs per year based on current usage:

Without Water Softener
Average Daily Water Usage Per Person127Litres(Measured Usage)
Daily Total381Litres
Daily total *365 Days139065Litres
m2 (Litres/1000)139.07Annual m2
Anglian Water cost per m2 (2021)£1.6015£222.71Water usage cost excluding standing charges
With Water Softener
Annual water usage139.07m2
Kinetico regenerates after 327 litres have been metered (meter disc Type 6)139.07/.327425.3Annual regeneration cycles
Regeneration cycles uses 20.5 litres425.3 * 20.58,718.14Litres – Annual usage
Regen m2 water (/1000)8.72m2
Anglian Water cost per m2 (2021)£1.6015£13.96Per Annum additional  water regeneration costs
Kinetico takes two blocks each 4Kg8Kg£5.25per 8Kg (2 x 4Kg Blocks) Bag
Salt used per each regeneration0.34Kg
Number of regeneration per 8Kg23.5Cycles
Regeneration Cycles/8Kg Cycles18.078Kg bags block salt per year
Annual Salt Costs£94.89
Regeneration Annual Water Costs£13.96
Total water softener usage costs£108.85£0.30per day
£9.24 per month based on 31 days
In Use

The softened water is fine to drink with no trace of a salty taste, soap lathers well with either hot or cold water, skin no longer feels dry and Barneys cocker spaniels coat is nice and silky now.

I need to remember to put the softener in bypass when I water the lawn so I have a reminder drawing in the softener cabinet and it has made us even more focused on using the water from the rain water butt.

Ezviz DB1 Video Door bell

I have wanted a video door bell with two way speech via an App for a while and like most people I’ve looked at the Ring and Nest versions but I wanted to keep my existing doorbell as it interfaces into my alarm and CCTV system and didn’t want to be tied into any form of cloud subscription.

After researching online, the ezviz DB1 seemed to fit the bill as it has internal storage capability, use of existing of wiring and can integrate into my home CCTV system for continuous recording, plus a number of other secondary features which appealed to me.

I bought the ezviz DB1 for £99.99 and a 128Gb Micro SD card for £19.99, both from Amazon.

The kit is very comprehensive and contained everything needed down to the drill bit and screwdriver!

Wiring couldn’t be simpler, turn off the power to your existing door bell, remove the outside push button and using the same wires, connect it to the DB1.

Inside the door bell, fit a small module across the bell connections, power up the bell transformer* and your all set for the next stage of downloading the App.

Bell Transformer* – My existing door bell transformers output voltage was set to 8vAC and this caused problems with the ezviz DB1 when trying to connect to the App, the transformer also had a 12vAC output which I tried but in my case the only solution which worked, was to buy another bell transformer with a 24vAC output.

The one I bought was from Screwfix and cost £8.95, this transformer will eventually be housed within my consumer unit and so it wasn’t worth getting an enclosure for it.

List of compatible door bells:

My doorbell is a Friedland/Honeywell D113 Surf 2 Note Chime, although its not on the list it work perfectly. The Surf 2 Note is available from TLC Electrical, (as of 17 Feb 2021).

The ezviz App was downloaded from the App store in my case and needed an account to be set up first which was very quick, following the instructions, the phones camera was used to scan either the QR code on the box or on the DB1 itself and after answering the installation wizards questions the setup was complete.

I chose to use 2.4Ghz rather than 5Ghz as the signal strength was stronger outside where the DB1 is positioned, within the App is a signal strength function to test wireless connectivity.

When everything is working correctly a solid blue ring is lit around the bell push button, pressing this causes the internal door bell to chime and the mobile phone will ring as though it is an incoming call, allowing you to accept or decline the call, if you answer the call, two way speech is opened up as well as video.

The DB1 has a presence sensor which can be set so that you are notified when someone approaches the door, the camera will then take a small video which is saved to the internal SD card for viewing via the App.

A schedule can be set in the App making this detection feature very versatile.

The App can also be shared so that other family members can view the DB1 camera or answer calls etc.

The ezviz DB1 does have a cloud subscription service if you chose to use it, however, I have a CCTV system with recording capability and so I simply added the DB1 camera as an input to this system which works very well, even at night due to the DB1 built in infra-red illuminators.

One of the secondary features I mentioned earlier was the ability to add wireless repeater chimes to the DB1.

I bought the CS-CMT-Chime from cctvdirectonline for £41.98, setup was via the ezviz App and it works perfectly in my garden cabin.

17 February 2021Relay Interface

My original door bell interfaced into my Pyronix Euro 46 alarm system and Hikvision CCTV, operating the bell push caused the door bell to chime and at the same time and event was logged on the Euro 46 with a push notification with video clip being sent to my mobile, this was the key driver for the DB1 that I retained the door bell chime so I could still have a link into my alarm.

Once the DB1 was all set up and working, I started on interfacing the door bell into the alarm and this is where I met a problem 🙁

The original interface was simply a 12v relay via a rectifier wired across the door bell chime connections, operating the bell push, the relay energized and triggered the Euro 46 alarm input, trying the same configuration, nothing happened when the DB1 was pressed.

I thought that the rectifier might be causing a problem, so I sourced a low power 24AC relay, again this was wired across the door bell chime and again, nothing happened when the DB1 was pressed!

Doing a google search I found that others had discovered the solution to the problem, I’m crediting Sam from the Konnected Forum for the method I have copied and used.

0.2 – 30A SZC23 – NO – AL – CH AC Current Switch

The AC Current switch was bought off eBay for £10.56, the recommendation from Sam was that a larger gauge wire was wrapped around the core about 6 times.

In the picture you can see the transition to the larger gauge current transformer windings, also the terminal connections to the Euro 46 alarm.

The SZC23 – NO – AL – CH AC Current Switch fits perfectly inside the Surf 2 Note door bell after some modification with a Dremel.

Schematic of DB1 Switch installed

Setting Up AC Current Switch

1. One of the supply wire from the transformer which feeds the DB1 is wrapped through the hole in the AC Current Switch and then connected to the DB1.With the DB1 powered up, the RED LED will be lit on the current switch, using a precision screwdriver, carefully adjust the sensitivity be turning adjustment pot until the GREEN LED comes on, then back it off slightly till the GREEN LED goes out. Pressing the DB1 should caused the GREEN LED to momentarily come on before both the RED & GREEN LEDs go out and come back on again, during one press of the DB1, the current switch will trigger twice.

2. Open the Ezviz App to view the DB1 camera and enable the microphone to speak to the DB1, this may cause the current switch to operate, if so, carefully adjust the sensitivity until this action no longer causes the current switch to trigger when accessing using your App, but still triggers when the DB1 is pressed .

3. The DB1 has infra-red LEDs which come on automatically when it gets dark, this increase power draw will trigger the current switch, as per 2 above, make the required adjustments and test operation.

Finished Job 🙂

Garden cabin electrics

This is a follow on from my Dunster House cabin build blog, please note that this work is notifiable under Part P of Building Control Regulations and should only be carried out if competent to do so.

I broke the cabin wiring process into a number of parts, these are:

  • Expected use of the cabin
  • Cabin power demand
  • Submain cable size, type and installation method
  • Existing house supply characteristics
  • Installation method within the cabin

Expected use of the cabin

The cabin is for recreational purposes and will be used throughout the year, this means provision will be needed for TV, lighting , gym equipment , general power both inside and outside of the cabin, exterior lighting, internet and a way to not only heat the cabin in the winter, but to cool it in the summer, all this builds a picture of power demand.

Heating the cabin will take the most power, so I used an online calculator work out heat loss and the energy required to raise the cabin temperature to 20 0 when the outside temperature is 00 , this worked out to be just under 4kW, I then allowed a further 2kW for an external plug-in patio heater should we be sat outside.

It is equally important that the cabin can be cooled for used in the summer, the highest temperature recorded in the cabin so far was 41.70 on the 24th June 2020, so the installation of an energy efficient Samsung AR18RXFPEWQX heat pump (5kW Cooling/6kW Heating capacity) was an obvious choice with a rated power consumption 1745W during heating.

Fixed loads such as treadmill, fridge and TV within the cabin are calculated to be 750W.

Inside and outside lighting is low energy LED and comprises of a total of 12 x 20W luminaires.

Maximum Demand

Adding the predicted loads together gives a demand of just under 5kW or 21.7 Amps, however, this is not the correct method, applying BS7671 18th Edition On-Site Guide Appendix A for diversity of circuit loadings, the maximum demand based on known and unknown loads after the application of diversity allowance factors and engineering judgement is 36.65Amps (8.43kVA).

The breakdown of this is:

WayCircuitLoad WAmpsDiversity Factor %Demand
1Low Level Sockets20408
2High Level Sockets10004.35Assesed4.35
3External Sockets20408
4Air Conditioning11.510011.5
5Internal Lights6402.4
6External Lights6402.4

Submain cable size, type and installation method

British Standards 7671 18th Edition in conjunction with the IET On Site Guide (OSG) and manufactures data sheets will enable all the cable calculations to be undertaken, however, their are a number of cable calculation tools online, this is an example of my cabin calcs, although I did do them manually before verifying the results with the excellent online toolkit from jarsoftelectrical (Cable-Mate) :

Project Name : Cabin Submain with Diversity Allowance

Cable ID / REF number : DB1/Way 1 to DB2

Supply Voltage = 230 Volts
Power factor = 1
Ib – Design current = 36.65 Amps
Protective Device Type = MCB type B (BS EN 60898)
In – Protective Device Rating = 40 Amps

Cable Type : Thermosetting ARMOURED 90°C – Multicore
Length of run of cable = 21 metres
Maximum permissible Voltdrop: 3% (Lighting) = 6.9 volts : Appendix 4
Maximum selected Voltdrop for this calculation = 6.9 volts

Installation Method : Sheathed, armoured or multicore cables direct in the ground:
with added mechanical protection (e.g cable covers).
An installation depth of 0.5 Mtr, A soil thermal resistivity of 2.5 K.m/W
(method D)

Ambient temp = 20 °C
Number of circuits including this one = 1
Length of cable in thermal insulation = none

Apply Correction factors:
From TABLE 4C2 : Cg = 1 (Grouping)
From TABLE 4B2 : Ca = 1 (Ambient temp) – Ground Temperature : 20 °C
From TABLE 52.2 : Ci = 1 (Insulation)
Protective device factor for Buried cables : Cc = 0.9 (Burried direct)
For an installation depth of 0.5 Mtr : TABLE 4B4: Cd = 1.03
For soil thermal resistivity of 2.5 K.m/W : TABLE 4B3: Cs = 1
Protective device factor : Cf = 1

It = tabulated current carrying capacity
It = In / (Cg x Ci x Ca x Cf x Cc x Cs x Cd)
It = 40 / (1 x 1 x 1 x 1 x 0.9 x 1 x 1.03 )
It = 43.15 Amps
From TABLE 4E4A Cable selected = 6 mm²
Current capacity of cable selected = 53 Amps

TABLE 4E4B For 6 mm²: mV/A/m = 7.9
mV/A/m corrected for power factor = mV/A/m x Power Factor = 7.9 x 1 = 7.9

Voltdrop = (mV/A/m x Length x Design current) / 1000
Voltdrop = ( 7.9 x 21 x 36.65 ) / 1000
Voltdrop = 6.08 Volts
(Maximum permissible voltdrop (regulation – 525) = 6.9 Volts)

Calculated Cable size = 6 mm², Minimum Earth conductor size = 6 mm² (Table 54.7)
Maximum Cable Length = 23.8 Metres

My calculated maximum demand is the worst case, it is highly unlikely that the sustained loading on the cabin will exceed my original value of 21.7Amps based on predicted usage, however, I have designed the installation to meet the current regulations and that includes cable sizing, I could have gone for a 10mm2 SWA cable but that would have been over-engineering in my view as all regulatory requirements are within parameters.

Trench contains 6mm 2 core SWA Submain and 1.5mm 3 core SWA external lighting cables, also 2 x 25mm flexible copex all bedded on sand with warning marker tape.
Flexible copex transitions to 25mm conduits, one conduit is spare to the cabin, the other contains 3 x Cat5e network cables and 1 x TV Coaxial Cable.
SWA marshalling cabinet from cabin for external bollards, deck & garden lighting including water features.

Existing house supply characteristics

The supply origin is TN-C-S referred to as PME (Protective Multiple Earthing), in this arrangement the incoming cable is of concentric construction:

Inner Phase conductor, outer conductors Neutral/Protective conductor

Only if certain conditions are met can this type of supply, including earthing, be extended to outbuildings, I therefore opted for a TT supply to the cabin which will have its own independent earth electrode with all cabin circuits protected by RCBOs (Residual Current Circuit Breakers with Overcurrent protection).

With a TT arrangement it is important not to ‘import’ an earth path from the house, therefore the submain SWA terminates into a plastic external enclosure, the TV aerial cable has a galvanic isolator installed to break the shield at the house and the Cat5 internet cables have no connection to earth.

Point of entry and exit for all cables, earth electrode connection point is also visible.
TV aerial cable Galvanic Isolator.
Three patch panel ports dedicated to the cabin, pink leads denote POE.

Installation method within the cabin

Wood expands and contracts with humidity by up to 12mm in my case, therefore the wiring method must be able to accommodate this movement, I chose to use Univolt 100mm x 50mm dado trunking installed all around the base of the cabin and to the consumer unit, from this trunking 20mm heavy duty PVC conduit is taken to lighting and high level sockets, this gives me total flexibility to add to the wiring system if needed.

To allow for expansion, I have used a combination of lubricated slip couplings for 20mm conduit joints and flexible conduit for movement transitions where appropriate.

The trunking is capable of having a partition piece inserted to make a segregated trunking compartment, this I have used for data and TV cables.

Cabin DB2, trunking has lighting switches for gym lights and dartboard, also power energy monitor and separate control for treadmill supply
The surface mounted back box with blanking plate under the consumer unit houses the Quinetic external lighting receiver.
D Line metal fire clips from Toolstation have been used to give additional support to the20mm conduit to prevent premature collapse in the event of a fire.
Tado Smart AC controller remotely operates the Air Conditioning and monitors cabin temperature.
Non Maintained emergency light at low level by the exit door should the lighting power fail to the cabin, to the side of the light is the test key and local fusing.
isigns did a great job of engraving my grid switches, this now removes any confusion as to what the switches do.
8 lighting panels were used and I’m really pleased with the light output and uniformity of coverage.
Sperate conduits for data and power, the TP Link Access Point is POE.
Heat Pump, I had this professionally installed (long story!)
Tado graph showing the temperature rise after just a short period of the Air Conditioning being set to heat.

The cabin consumer unit has 6 RCBO protected ways these are for:

  • Way 1. Low level dado trunking socket outlets (B20)
  • Way 2. High level sockets via conduit (B20)
  • Way 3. External IP rated double sockets (B20)
  • Way 4. Air Conditioning unit (B16)
  • Way 5. Internal lighting including emergency light (B6)
  • Way 6. External lighting and water features (B6)

The cabin area is 29.25m2 and the OSG Table H2.1 final circuits to sockets outlets are Type A3, Radial using 2.5mm2 singles.

Low level dado trunking has 13 double sockets, the vast majority are not used but as the cost per socket is less than £5 it was worth doing, the high level socket circuit only has 1 double socket and one single socket so I’ve assed the maximum load to be 1000w as these sockets are dedicated to low wattage chargers and a TV it is highly unlikely this will be exceeded, especially considering the number for dado sockets 🙂

I have installed 3 double IP rated external sockets as a separate Type 3 Radial circuit.

Internal lighting cables are all 1.5mm2 singles, external lighting and water feature cables are 1.5mm2 SWA.


Having used the cabin for a year, one of the things I didn’t install at the time was a means of two way switching the cabins outside lights on or off, I thought the external security light sensors on the house would bring the house mounted lights on if someone left the cabin at night, unfortunately this wasn’t the case, so the first few steps out of the cabin were in pitch darkness, which is less than ideal.

The solution came with Quinetic switches from TLC, these are quite amazing as the switches need NO POWER, they internally generate enough energy to transmit to a receiver which could be up to 30m away.

Grid switch module from Quinetic

The above picture shows a two gang switch plate, originally this was only a single gang switch for the utility light by the back door, changing this to a grid switch allowed me to have the first switch as the utility light and the second switch as a Quinetic module remotely and wirelessly turning on and off the external cabin lights.

In a previous picture of the cabins four gang switch, the external lighting switch is also a Quinetic module, both paired to a single receiver operating the lights, I also have a keyfob paired to the receiver giving me maximum flexibility in operating the lights.

This modification was very easy to do with no mess, unlike the traditional method of hardwiring and cable chases.

Replacing Rotten Porch Support Post

It all started so innocently, I thought I would give the post supporting my porch a coat of paint, so armed with a blow torch and scraper I started to prepare the post until my scraper sunk into the soft wood at the bottom of the post 🙁

At this point I could have stopped and simply painted over the rotten wood, but as it was a nice day I got a screwdriver out and explored the extent of the rot.

This ended up being quite extensive.

I scraped out all the dead wood and tried to figure out how it had rotted, the post is inside a galvanized shoe and all I can imagine is that water has sat in the shoe and ‘wicked’ up the post and rotted it.

Once it was back to decent wood and left to dry out, I used Ronseal exterior wood filler over a number of sessions to make good and finally sand down and give two coats of gloss.

Once painted up it wasn’t a bad job and I was really pleased with how it turned out.

Rolling the clock forward 4 years and as my first retirement project and in the March 20 lockdown, I thought I would spruce up the front of the house staring with painting the post, so out came the sandpaper.

Once I started to rub the paintwork, it was obvious that the wood was soft in areas where the filler wasn’t previously and it was at this point I decided to bite the bullet and replace the post.

The unknows were how is the post secured at the top and at the post base also could I replace the post with little or no damage to either the wall or the UPVC barge board and cladding.

The two thing I knew was that the porch will need support once I remove the post and the second thing was that I’m rubbish with wood so splicing into good wood on the exiting post was out of the questions.

Very little information exists about the construction method used to support the porch, hence this blog to help others who have a rotted post problem.

Before starting I sourced and bought all the materials which I thought I needed.

The replacement post was a Stop Chamfered Porch Post 2100mm x 95mm x 95mm and bought online from RMJM Joinery Ltd and cost £56.97 including shipping.

The part number is SCPP2100 and is engineered timber meaning it is two pieces of wood laminated together giving a high strength, warp resisting, structurally sound post with no knots.

I bought a couple of used Acrow props of Facebook marketplace for £20, which was cheaper than hiring and started to figure out how I was going to do the post swap with minimal damage to the UPVC facias.

Checking the online forums, the general consensus was that getting the polytop pins out which hold the facias on was impossible without damaging the soft surface finish.

I ordered a small number of 30mm and 65mm polytop pins from ebay for £5.70 and looking for replacement UPVC cladding, I couldn’t believe my luck that a wholesaler who sells to the public was based in the town.

AJW Distribution had everything in stock I needed to replace anything I would damage, also they were very friendly and helpful.

I started by removing the guttering and porch roof tiles so I could figure out how the post is attached at the top, trying to save the UPVC was futile, so off all that came too.

Before the post was cut, the porch was supported by a substantial diagonal brace and bricks enclosing the base of the post removed. Using a nail puller, the nails at the top of the post came out easily, leaving the post to be cut and removed.

Nail Puller

The post base was seated in a galvanized shoe, once the soldier bricks were removed it exposed that the shoe base was sitting about 10mm off the second course of the brick wall.

Once I pulled the shoe out of the wall it exposed a locating spike which must have been sitting on the third course of bricks and all the weight of the porch was being transferred as point loading through the spike to the bricks below, a really rubbish construction.

Checking online, it look like the shoe has been modified as the base of the spike should have had a plate attached to spreads the loading, but I might be wrong.

The picture below shows the shoe fitted to the new post, the spike had been bent during original installation and I can only assume this was done in order to get the post level and true vertically.

Picture showing galvanized shoe on new post

Once the post was cut out, it was quite a job to get the residual wood out of the shoe to allow me to reuse it.

The picture shows the post damage over 300mm up from the base where I made the cut in removing the post.

The new post was an ‘interference’ fit into the shoe as I didn’t want their to be a gap allowing water to ingress between the post and the shoe, this meant I used a big hammer to knock the shoe over the post, it certainly wont come out in my lifetime 🙂

Fitting the new post back was very straightforward, once measured and cut to length, the post shoe spike was located back in the gap in the wall and the top of the post securely bolted at the top on both elevations.

I had packed the shoe base with mortar as it was being installed to spread any loading. I had to get two new bricks which unfortunately don’t match the existing (London Brick Company, Honey Buff), but I kind of like that as it shows the post has been changed.

In the picture above you can see a strip of masking tape, this is covering a piece of oval 15mm copper pipe which goes under the shoe and will act as a drain should water try and collect at the base of the post again.

The finished job, I replaced all the facia boards and cladding, including adding cladding edges, which was a significant improvement on how the house builders finished the porch, the overall cost was less than £150.00 including undercoat and top gloss paint.

Not much to look at once its all done, but I know it will last another 20 years and hopefully longer.

Intruder Alarm Circuit Test Box

I thought I’d build a test box which will simulate the three circuit conditions of an intruder detection system (IDS), these being:

  • Circuit Tamper
  • Alarm Condition
  • Circuit Healthy or Closed (non alarm condition)

The purpose was to confirm and test the ’cause & effect’ programming of a Pyronix Euro 46 panel , the Euro 46 remote Upload/Download Software allows for logic gates to be configured, so the system ended up being very versatile.

The above picture shows the Euro 46, Keypads, Zone Expansion, Output and Wireless modules set up for testing using the multiswitch test box, the alarm system is communicating with the Pyronix Cloud server via a LAN interface, cloud configuration also allows seamless integration with the Hikvision CCTV system.

The Euro 46 has several detection circuit configurations, I chose the common value for a Double End Of Line resistor system of a 2k2 and 4k7 Ohms.

At the detection input a healthy or closed circuit, would measure a resistance value of 2k2 Ohms, if the value either exceeded or fell below this by a defined margin, the alarm panel would see this as a tamper condition, and alarm condition would present a value of 4k7 Ohms, the test box achieved the three conditions listed using the following diagram:

The above circuit presents to panel with slightly more resistance than 2k2 when healthy, however, as its within the parameters, the panel see’s this as closed with no faults.

The completed unit was built using 30 switches and I utilised an old piece of trunking to fit them in:

The circuit description label temporarily sticks over the laminated switch backing so I can fully program and test the wired circuits before installation in the future, one element I can’t test is the wireless aspect which forms a a large part of this system.

BRK Smoke Alarm Relay Interface

I have a number of BRK Smoke and Heat detectors which are interlinked to all sound on activation of any detector, I needed a way of linking the detectors to my house alarm which in turn would alert me on the mobile app.

A quick Google search flags a BRK RM4 relay interface which is triggered by the interconnect wire, the problem is they are only for the US market and work at 120v AC, this was confirmed with a phone call to the UK BRK representative.

I decided to take a punt and bought a RM4 from a US vendor, this took ages as a large number of seller just wouldn’t entertain shipping to the UK.

The moment the RM4 arrived, it was cut open 🙂

After checking the component data sheets the only parts which needed upgrading were the 2.2uF capacitor from 50v to 250v and the relay from 120v AC to 240v AC (part 369-337: G2R-2 230v).

Before swapping the parts I set up a ‘rough and ready’ test rig using a variostat to provide 110v AC to the RM4, a clamp meter was used to measure RM4 consumption and a 9v battery ready to place a voltage on the interconnect wire simulating an alarm condition, this worked fine.

After exchanging the capacitor and relay the RM4 was back on the rig and the supply voltage gradually increased to 240v AC while keeping a close eye on the current consumption which slightly increased from 2.8mA to 3.3mA.

The interface works as expected and the relay energises when a voltage is on the interconnect wire, it must be noted that the interface requires a supply voltage for it to work, the relay will not work in a power outage.

The RM4 wires are coloured for the US market and required sleeving with UK colours:

  • RM4 Relay White wire = UK Blue Neutral
  • RM4 Relay Black wire = UK Brown Live
  • RM4 Relay Orange wire = UK BRK White Interconnect

Carsare Grande Log Cabin

Link to Cabin Electrics Blog

Link to Cabin Overhang Dimensions

This is a short blog on the process for constructing a Carsare Grande Log Cabin from Dunster House. I dealt with the Bedford branch as its the nearest to where we live and took a trip to look at the build quality and also armed with a tape measure, confirmed some dimensions, Samson the sales representative was very helpful and non pushy which made the visit very relaxed.


The garden was overhauled in 2006 when we first moved in and we were very pleased with it, but over time the maintenance became a burden and we only functionally enjoyed it for a limited time over the year, so we decided to make better use of the space and explore options.

Not sure which family member suggested a outdoor building, but it made sense and so the seed was sown.


Research included all aspects of an outdoor building, this included compiling budgetary costings, proposed purpose, design options and what permissions are needed.

So it quickly became obvious that a home gym with a recreational space was the preferred option, the gym would need plenty of room for equipment and be tall enough to stand in with arms lifted, the rest of the space would be for games and seating, looking at my gardens available area, a 6.5m X 4.5m outbuilding would fit.

Checking with the UK Planning Portal, outbuildings are a permitted development (Class E) as long as certain conditions are met, the key criteria that I needed to meet was below, (my answers in bold) –

1 Purpose – Incidental to the enjoyment of the dwelling house. (YES)
2 Over 50% of the total area of the curtilage used. (NO)
3 Any part forward of the principal elevation. (NO)
4 Single storey. (YES)
5 Total eaves height restricted to 2.5m is within 2m of boundary. (YES)
6 Listed building. (NO)
7 Verandah, balcony or platform over 0.3m. (NO)
8 Microwave antenna. (NO)
9 Less than 30 square meters floor area. (YES)
10 At least one meter from any boundary. (YES)

The key document is below:

The outbuildings construction is not stipulated in the Guidance, however, I’m no builder, so the option to buy a prefabricated kit seemed a good idea.

After quite a long time online looking at different vendors and weighing up the pros and cons, we went for a 6.5m x 4.5m Dunster House Carsare Grande, 45mm thick timber interlocking walls, non insulated.

The following files relate to the Carsare Grande we have:

We decided as the cabin will not be a habitable space or used as an office, their was no need to have insulated walls also we didn’t take up the additional expense of roof insulation or gutters and downspouts from Dunster House as part of the purchase, more about this as bit further on.


OK, now we know what we are going to have, what it’s for and how much its will cost, the next bit is the base the cabin will sit on, here we had three main options, all of which required a level of excavation works and spoil disposal, I excluded simply building it on top of the existing grass as I want it to last!

Option 1 – Concrete Pad, The recommendation is that the base should be 150mm thick, as the cabins footprint is 6.5m x 4.5m, the foundation slab, needed to be bigger than this, the amount of concrete works out to be 4.46 Cubic Metres, and as the plot is 25m from the road, the concrete would have to be pumped as using wheelbarrows would need 50 trips and that would incur additional waiting time costs for the cement mixer driver and knowing my luck, the cement would have started to set before I had finished! also the cost for concrete, rebar and pumping made this unaffordable, putting aside the fact that restoration of the garden at a future time would be expensive.

Option 2 – Concrete Block or Slabs, Heavy manual handling and these would need a foundation and getting level would be difficult over such a large area.

Option 3 – Plastic Pro Base – This sits on a bed of pea gravel with a weed control sheet under the gravel, each base grid is physically interlocked into place and the spaces in the Pro Base grid are filled with more gravel to give stability and add to water drainage, this was the option chosen.

The base was marked out to give the required minimum 1 metre distance from the fences, this worked out perfectly as its enough space to comfortably get around the cabin to build it, apply stain and maintain it afterwards.

In total we used 4 bulk bags of 10mm pea gravel for the cabin base and the base dimension is 7m x 5m. The cost of excavation plant, labour, skips and base materials cost ~ £1350, so make sure you budget for this! To get the base level we used a laser level with remote detector, this was perfect for our needs, good value for money and easy to use. The model number is Firecore FIR411G and was bought from Amazon.

Dunster House

As mentioned earlier on, we went though to the Bedford showroom and when we got home placed the order using the online portal, this was very easy to navigate and the order tracker was informative. The lead time on the Cabin was eight weeks which was good as it gave us some time to prepare the plot, but after just three weeks we had a phone call asking if they could deliver, at which time we hadn’t even started preparing the ground!!

On the revised delivery date the cabin arrived, I paid for a two person delivery and the guys were very helpful and placed all the parts, of which their was loads , onto an area I had laid out. The parts come off the lorry in no particular order, so some sorting out is needed afterwards, my Cabin is made of two distinct sections and these sections need to be kept separate to avoid mixing up the parts.

Oh, one tip, on the ordering portal you can track the delivery on route to you, don’t believe its accuracy and wait for the order to arrive in case you think it will be OK to nip out 😉

The Build

Tools I recommend you have in advance are:

  • Spirt Level
  • Pencil
  • Rubber Mallet (I used a white head type from Screwfix to avoid marking the wood – Part Number 2472V)
  • Drill and wood drill bits (3mm, 6mm & 8mm)
  • Impact screwdriver
  • Flooring Clamp (Screwfix – Part Number 932FT)
  • Step Ladder
  • Adjustable spanner
  • Tape Measure
  • Right Angle
  • Hammer
  • Tube felt adhesive and applicator gun
  • Stanley Knife and spare blades
  • Wood Saw

The first job of the build is to identify the parts, this starts with the floor timbers, as the cabin is made up of two cabin bolted together, you have two lots of instructions and the floor timber spacing’s are different, this will mean that the floorboard screws will not follow a straight line throughout the finished floor, my OCD would not allow this, so I had to take apart the floor timbers and make sure that were all in line. Not a big job, but as its the first thing to do, undoing your work is a bit demotivational.

The walls progressed quickly, simply slotting into each other, a bit of persuasion with the mallet helps to ensure the wood interlocks. I opted to have the window on the left of the door as you look from the outside, the reason for this is that we wanted a seat under the window which would be in a corner and the door would open with an internal wall on the right enabling the light switches to be easily operated without walking across a dark room to operate the lights.

Dunster House provide spare parts, so it may look like you have bits left over from the wall build, but this is intentional which was unexpected but welcome as we did have a couple of lengths with a twist in them.

Once the walls are up, roof joists tie the gable ends together, this is the only doggy part of the build, as for a moment in time, the gables are unsupported.

With the roof joists in, the next step is to board the roof making sure to use the roof boards and NOT the floorboards, they are different dimensions, so if you start cutting roof boards, your doing it wrong!

The construction guide says to leave a 2mm gap in the tongue & groove for expansion rather than have each piece butted up to each other, what we found was that as the wood had been outdoor for a while it had started to twist, the only way to get the boards to engage throughout their length with the next piece was to use a flooring clamp to pull the pieces into shape, this worked really well, but took ages. It was important to get this right as the boards are the cabins ceiling finished surface.

The kit comes with a under-felt plastic barrier and felt shingles, an extra Dunster House offer is roof insulation for £858. I decided to install my variant of this warm roof system which cost ~£250.

The first step was to install a vapour barrier on top of the roof, once this was done, a 25mm wooden baton was secured all around the perimeter edge of the roof. Due to planning rules the building cannot be over 2.5m high, this limits the thickness of the insulation to 25mm, hence the insulation is the same thickness as the batons.

With the insulation boards cut and fitted to shape across the roof with the reflective side upwards, I used aluminium jointing tape to seal the boards, the insulation was then covered by 9mm plywood and screwed down, the roof boards are 19mm thick, so 50mm screws were used, but not driven too hard as I didn’t want them to show inside the cabin ceiling.

The plywood joints and screw heads were covered with a waterproof tape and a waterproof membrane was rolled out on top of this. I tried to used the plastic sheet which came with the cabin kit, but it was impossible to get it to lay flat, so this was discarded and I used Protect A1 Roofing Underlay from Screwfix.

The last item in the warm roof process was to installed the roof felt shingles and affix them with the supplied galvanised clout nails.

The Tip for cutting felt shingles is to change the blade after 4 cuts maximum and to clean the blades between cuts with White Spirts. The shingles go down quickly and I had a pack and a half left over, so they do give you plenty.

Once the roof is complete, the boards for the gutters and end boards go on. Dunster House wanted £330 for the rainwater kits which included water butts, I bought the same system parts from B&Q for £150, if you keep the receipt you can take unused parts back for a refund which worked really well for us.


Once the cabin was watertight we could focus on getting the floor down, the cost for an insulated floor was £300, so like the roof, we bought the materials from a local builders merchant and saved money. I fixed small blocks to the side of the floor beams to keep the insulating board off the floor and allow an air flow, the insulation boards were cut with a saw, and pushed into place and all joints sealed with tape or expanding foam where needed, before the floorboards were screwed down, we used the flooring clamp to get the wood to fit in order to get the finish we wanted.

Finish & Interior

I bought the wood stain from Dunster House and applied two coats as per the recommendation, the stain dries very quickly and runs easily, so take your time as the finish is worth it. The stain is a quality make and I couldn’t find it cheaper elsewhere, 2x 2.5l tins is more than enough for at least two coats of the cabin, windows and doors.

The double doors need door hook & eye stays to keep them open, these are a lot cheaper online than from Dunster House.

I undertook the electrical works, this involved digging a trench to carry 1x 25mm flexible conduit containing 3x Cat5e data cables and a Coax cable for the TV, also in the trench was a 6mm 2 core SWA for power, inside the cabin I used a 6 way consumer unit with RCBO’s. For ease of installation and future expansion if needed, I used dado trunking around the complete perimeter at low level, I was advised that the wood will move with humidity, so the trunking is fixed to one length of wood and not screwed to bridge separate lengths. All electrical bits came from TLC Electrical and they are my go to supplier. Within the dado trunking is partition separation between the data and TV cable and the power circuits.

The cabin has a WiFi Access Point as well as hard wired tap points for flexibility.

Lighting is by 300mm x 300mm LED panels, 4 on each side of the cabin, 8 in total.

Time to Relax

Floor tiles were fitted as the plain floorboards got too dirty with all the construction works, the tiles were good condition used ones and bought locally from Fuller Gray Carpet Tiles.

The only part of the cabin I didn’t do was the installation of the Samsung split unit Air Conditioning, this has the facility to heat or cool, this was sized to give 5kW of cooling or 6kW of heating, this method of heating uses less electricity for the comparable output than using traditional heaters.

We are very happy with the quality of the cabin and the all year round usable space it has given us, I would recommend this to anyone.

SGC Auto-Tuner SG-237 Repair

I have had the SG-237 for nearly 5 years and it has worked perfectly matching my random length wire across the bands, due to changes to the garden, I had to power down the SG-237 for a few weeks, on powering up, nothing would tune.

Checking current to the tuner showed that no power was being drawn, so off came the lid, and out came the voltmeter.

Tracing 12v through the circuit, it appeared their was a break between jumper J5 and the fuse holder, (the 2A fuse was in tact), but I couldn’t see any damage to the PCB tracks.

The reply from the SGC support ticket was within two days and their tech support said this was a very unusual fault and bridging from J5 to the base of the fuse holder was fine.

I can only deduce that the track link is made within one of the layers of the multi layer PCB, I did try and re float all the relevant solder connections, but this didn’t work unfortunately.

In the end, I soldered a link from the diode, bypassing J5 as I’ll never remove the link to the fuse holder, this link now removes another future point of failure and everything works just fine 🙂

Bird Bath Auto Water Fill

start pic

I bought my bird bath second hand for £10 and have had it for several years, I’ve always hated the colour and topping it up with the watering can every day was getting to be a pain.

So I thought I would ‘ kill two birds with one stone’, (I know, not the best phase considering the context), anyway, a nice little project in the making.

My original design ended up way to complex, the plan was to use a Programmable Logic Controller to drain the bowl and refill it everyday, plus some other tweaks such as overfilling the bath to flush out waste and only draining down at night etc.

I did a relality check and simplified the design to simply fill when the level in the bowl gets low, however, the plumbing manifold was made to allow auto draining if I choose to do it later.

Current Operation – This is very simple and needs no manual intervention. With the water supply and power on, the liquid level controller keeps the solenoid fill valve closed as long as a circuit is made via the water from the common connector (metal tank connector) to the low level brass stud.

When the water level drops below the low level stud and the contact to the common connector is missing, the controller, after a short delay, powers the fill solenoid valve and water enters the bird bath, once the water touches the upper contact (high level), the solenoid power is removed and the valve closes.

How it was made – As the bird bath is made of plastic and the top bowl lifts off the column, I was able to put hardware out of view inside the base.

First job was to drill and fit the 15mm Tank Connector (£2.79) and a small length of 15mm copper pipe in the top bowl, this will connect to the filling manifold via a push fit coupling, the copper stub will also act as a ‘Common’ connector for the level sensor circuit.

dish top

The manifold is made of 15mm copper pipe with end fed fittings, the manifold is connected via a 15mm ‘push fit’ connection to the bowl stub, thiis makes maintenance very easy as it all comes apart quickly. The finished pipework is fully lagged.

inserted manifold

The liquid level control PCB was off eBay (£3.65 and) fitted neatly inside an IP rated enclosure I already had, in the picture above you can see an earth wire which is soldered to the stub pipe from the bowl and the black cable is a two core to the high and low level stud contacts.


The solenoid is 1/2″ version, 12vDC and connects to the water supply via 15mm tap connectors with fibre washers (£1.50 @ B&Q), I fitted a flywheel diode across the terminals to avoid pitting the PCB relay contacts, the valve was off eBay and cost £4.32.

The studs are Pan Head 12mm x 4mm brass machine screws commonly used for metal conduit box lids, the studs are positioned at the low level and high level marks. On the underside I have used hot melt glue to secure the sensor connecting wire.

Finished bb

Finished project and a new colour, Winsor Green. The water supply to the bird bath is via a hose from an outside tap, the connection at the bird bath is via a hozelok connector with an isolating ball valve, the valve is ‘gagged in’ so the when the solenoid opens, the bath fill is quite slow,

12vDC to power the circuit board and solenoid is fed from an external IP rated socket with a small plug in PSU.

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