Central Heating Frost Protection

Due to the recent cold snap and the fact that my central heating boiler is in the garage, I thought I’d install frost protection which will override the heating controls and fire up the boiler when the frost stat air temperature is  at or below +5℃, on the return pipework to the boiler is pipe stat set for +25℃ to turn the boiler off.

I have a Hive system which has a frost setting on the internal thermostat, this will bring the heating on if the temperature falls to +7℃ or below, the garage frost protection supplements this.

I spotted the Honeywell Frost Protection Kit – K42008628-001 comprising of a Frost Stat and Pipe Stat for £27.00 on eBay which is a really good price compared to Screwfix, Plumbase and Toolstation, so I bought it.


For the installation, apart from the stats, I needed some heat resisting cable for the pipe stat and a double mounting box.

2 core and earth (3093Y) 0.75mm2 heat resisting white round flexible cable was bought off the internet from Under Control Instruments (www.undercontrol.co.uk)  for £4.00 which is temperature rated to 85℃.

The double gang surface box took a little bit of searching as I needed one with the flexibility to be used either vertically or horizontally with face-plates in the correct orientation, this cost £3.99 off eBay.

Original installation showing the boilers isolating switch, the white flex is from the pipe stat.

First job was to wire the pipe stat and install it on the return pipe to the boiler, the stat is held in place with a spring which hook onto lugs on the base of the stat, getting the spring behind the pipe and stretching it to fit was made easier by tying a piece of string to one end of the spring and passing that behind the pipe.

Hooking the spring on the stat lug and keeping tension on the string, offer the stat to the pipe and pull the string to stretch the spring round the back of the pipe and hook it on the opposite lug, once done the string is simply cut off, this worked very easily once you got the knack.

pipe stat

With the power isolated, the existing isolator was opened and a picture taken for reference.

The Blue (Neutral (N)), Yellow (system calling for heat – switched 230v (L2)) and Red (Live (L1)) are from the junction box wiring centre, the opposing wires in the isolator are to the boiler.


Once everything was identified and proved dead, the wiring was removed and the new double gang surface box was fitted and wires pulled back in.

The two red sleeved blacks were separated, one will be connected back into L2, the other will be used by the frost protection system.




The isolator was wired up and screwed into place, then the frost stat was fitted but it did not sit right as it was very slightly smaller than the back box so I needed packing to make it level, for this I used an off-cut of trunking lid, which did the trick.


Once the Froststat was fixed in place and connected, the power was turned on and the frost protection tested by simulation that everything worked ok, including the operation of the Automatic Bypass Valve, once done the trigger temperature was set and the stat lid fixed in place.

I did notice a draft from behind my changeover switch on the left of the picture which was blowing across the face of the froststat, so I sealed the gap with decorators caulk to avoid inaccurate operation of the stat.

frost stat
Froststat and isolator, I bought additional lower cover screws and two were missing, the part number is Vaillant 290811 Clips.

As I have recently installed an Automatic Bypass Valve, I have not connected the frost stat to any motorised zone valves, therefore, once the air temperature is at or below +5℃,  a switched live will be applied to the boilers ‘calling for heat’ via the red sleeved black wire, the boiler will now fire and the circulation pump will operate.

As the motorised valves to either the central heating or hot water cylinder will be closed (‘S’ Plan system), the pumped water pressure will ‘lift’ the automatic bypass valve, maintaining a heated water flow to the boiler via the return pipework to which the pipe stat is affixed.

Once the return pipework is above +25℃, the pipe stat opens the series wired connection from the frost stat, this removes the switched live to the boiler, and the boiler enters ‘no heat run on mode’ before switching off.

The job took 2 hours and cost £35.00 and although we have never had a problem, the boiler and pipework in the garage should have had effective frost protection from day one.


19 March 18 – The boiler came on unexpectedly and it was caused by the frost stat, closer inspection reveled that one of the bimetallic switch support pillar was snapped inside the unit, I’ve contacted the seller on eBay to see if I can get a replacement.

20 March 18 – eBay seller responded to my mail and is sending a replacement unit out.

24 March 18 – Replacement froststat arrived in good order and installed, all working now and the original unit sent back to the seller.

BRK 86RAC Smoke Detector Replacement and Additions

I have two BRK 86RAC Ionisation type smoke detector, one in the Hall and the other on the upstairs Landing, these were installed by the builder and in 2008 I added a heat detector (690MBX) in the garage, all three devices are mains powered with battery backup and are interlinked so that they all alert to a detection.

BRK 86RAC Discontinued ionisation smoke detector.

Checking the batteries in the smoke detector I noticed the unit has a life of 10 years from date of manufacture which was 21 June 2002, as the date of noticing this was 4 March 2018, they are well overdue for replacement!

The BRK 86RAC is no longer produced and has been replaced by the  BRK 670MBX.


Checking my local Screwfix had BRK ionisation smoke dectors (part number 81969) for £12.99 and the surface mounting kit (part number 30152) for £2.99, I thought I would add two more to my system, so bought  four of everything.

On opening the boxes, I didn’t realise that the detectors came with 9v PP3 type batteries, so wasted £6.00 buying them, and the other thing was that they are not a direct replacement, the 86RAC base is a smaller size and the plugin connector is a different style.

In the box are the above plus instructions, sticker for the consumer unit and protective detector cover, no fixing screws are supplied.
Fitting –

First job was to isolate the mains supply to the existing detectors which are on their own dedicated circuit, once this was done I twisted the detectors from the base to allow me to take photographs of the wiring.

The existing wiring was Black to Neutral, Brown to Live and Orange striped is the interconnect wire, 670MBX uses Blue for Neutral, Brown to Live and Grey for the interlink, the existing detector had a ferrite bobbin through which all the detector wires passed, whereas the new model doesn’t, I decided to reuse these on the replacement units.


Once the cable colours were recorded, the detector was unpluged and the base completely disconnected to allow the replacement of the new base, once this was screwed into place, the connections were remade.


The wiring in the base looks more complicated than it should due to the change of cable colours, the existing 1mm CSA 3 core and earth used the pre EU harmonisation wire colour convention of Red, Yellow and Blue,  the cable to the new additional detectors which I have installed are in the office and IT cupboard, uses harmonised colours of  Brown, Black and Grey, as the installation has mixed wire colouring, a warning notice to this effect is fixed to the consumer unit.

While the new detector was on the desk, the battery was dated and connected, without a battery installed the detector will not engage in the base, this is a safety feature.

After making the connections, the detector base was fixed to the surface fitting by two supplied screws, the cardboard sealing gasket was then pressed into place covering the detector base fixing holes, the next step was to plug the lead into the base of the detector and lastly twist the detector into the base.


Within the baseplate of the detector is a small plastic extrusion  which can be removed, this is used once the detector is installed as a locking clip preventing the detector being removed from the base with the clip in place.

With all detectors connected and new ones installed, mains power was turned back on, and each detector was then checked that it showed a continuous green LED for power healthy and a flashing red LED every 60 seconds to show the detector is functioning.

The center test button on each detector was pressed and held, this caused the local unit to sound, followed a moment later by all the other interconnected heads.

I had already sealed the cables passing through the ceiling, the final job was to seal the base to the ceiling and paint the exposed part of the ceiling as a result of the base being smaller than the original one.

A point to note was that I was going to use flushed in circular dry lining boxes to make the connections in and hold the base, this would have made the smoke detector sit closer to the ceiling but would of meant a large hole being made, so I decided against it.

Job was very straightforward, adding new detectors was easy as I looped off the landing detector to the other units which were only a few meters away.

ESi Electronic Hot Water Cylinder Thermostat – ESCTDE/B

In order to save energy and better regulate the temperature of my domestic hot water in my Santon Premier Plus unvented cylinder, I decided to install a ESCTDE/B Electronic Dual Cylinder Thermostat manufactured by ESI Controls, I bought online from PlumbNation.


The ESCTDE/B has two thermisters, one for the temperature reading and control, the other is for over-temperature trip and is set for 80℃, I must have a big problem if this operates as my boiler output temperature is set to 68℃.


Fortunately the Santon Premier Plus has a spare thermostat pocket which the thermisters are a perfect fit.


I marked the location of the thermister pocket on the outside of the cylinder cover and offered up the ESCTDE/B back-plate and marked the centre hole.  I’m not sure what the ESCTDE/B is specifically designed to fit, but the rear fixing was perplexing and I didn’t want to modify the casing of the unit in case I invalidated the warranty.

Rear fixing arrangment

I used a cut down 20mm Female Adapter as a center bush, this was cut to size and fixed to the front cylinder cover.

20mm Female Adapter
Cut down female adapter used as a through cover fixing method.
Fixing bush installed.
Inside cover showing bush and thermostat pocket.

ESCTDE/B fixed to the bush with the three back-plate screws and as the female adapter has a serrated edge, it holds very well, the existing cylinder thermostat was turned up to position 5 which is 72℃, I have left this in circuit as another backup to over-temperature, as mentioned earlier, my boiler output temperature is set to 68℃, so only under a fault condition should this protection operate.

Indirect temperature setting and top view of fixing to ESCTDE/B.
Thermistors sliding into cylinder pocket.

NOTE – The mains supply to the ESCTBE/B MUST be from the same source as the heating systems programmer, this will ensure that there is only one point of electrical isolation for safe working.

I used 1mm 4 core and earth from the ESCTDE/B to the heating connection box, the ESCTDE/B does not have an earth connection, so this wire was parked, the unit requires a permanent 230v feed, the temperature calling relay changeover contacts are NOT volt free, although they are simply wired in series with the existing cylinder thermostat.

If the Legionella setting is active on the ESCTDE/B, the unit will automatically switch 230v to the Domestic Hot Water motorised valve (NOTE- this overrides any programmer settings), which in turn will bring on the heating, the output from the ESCTDE/B will remain on for 1 hour when the tank temperature is above 61℃.

As the bending radius of the connecting wires within the unit is quite tight, I used ferrules on the end of the wires, this ensures that no ‘whiskers’ can cause problems later.

Ready for wire stripping.
Insulation removed and conductors twisted.
Bootlace ferrule pushed on.
Bootlace crimped and job done.

Finished installation all working, as my hot water system is directly fed, (no header tank), I did not need to enable the ‘disinfection mode’, this mode increases the water temperature to 61℃ to kill Legionella, however, as the feature exists, I set it to activate once per week.

We had been away for a few days hence the water temperature was showing 21℃, the unit was initially set for 48℃ and the Red lED shows the cylinder is calling for heat.
Picture showing wiring from ESCTDE/B to heating terminal box and the tank temperature now reached the set-point of 48℃.
Link to ESI Controls Information:

Central Heating Enhancement

I was reading on the plumbing forums about the need for an Automatic Bypass Valve (ABV) on central heating systems and compliance with the HM Government  document – Domestic Building Services Compliance Guide, specifically the need for a ABV (page 15, section 2.0).

I have a System configuration using a Valliant Thermocompact 624e boiler, the purpose of the ABV is to maintain a consistent flow through the boiler and also should both the hot water and central heating zone valves close due reaching the set point temperature, the boiler will continue to run for 10 minutes to dissipate heat in the the boilers heat exchanger, without some form of bypass the pump will be pumping against closed valves, which is not good!

The ABV senses the increase in pump pressure and opens against a calibrated spring pressure to maintain water flow.

S Plan

My central heating system had a 15mm hand valve cracked open between the boilers flow and return for this purpose, the 28mm pipe with an automatic air vent is the feed from the boiler, the centre 22mm pipe is the return.


The advantage of this configuration is that the pump can not pump against a dead head, the disadvantage is that a portion of the heated water from the boiler is immediately returned to the boiler and not used the heat radiators or hot water, so I thought I’d install an Automatic Bypass Valve not realising that the boiler already had an inbuilt one until I had bought all the parts…oh well!!

The manual bypass valve was not the only thing I wasn’t entirely happy with, the main niggles were the motorised valve to the heating circuit was mounted very low and it would be better to move it higher for ease of replacement and the automatic air vent was not at the recommended height above the highest point in the system, both of these were going to be fixed at the same time as the installation of the ABV.

First job was to electrically isolate all power to the boiler and controller, once done it was a matter of draining the system down, I’m fortunate that my radiators have drain valves, this made the process very simple.

Once drained I could disassemble the pipework.


I retained the hand valve for adding inhibitor and for use as a vacuum break should I need to drain down in the future.

Once the pipework was apart, I used a 22m straight compression coupling to extend the central heating pipe, lifting the motorised valve  to a more accessible location, the pipe to the automatic air vent was also extended to be 300mm above the height of the upstairs radiators.

The tricky job was to unsolder a 22mm stub which was cut to allow the pipework to come apart.


With the heat mats in place, I was surprised how easy it was to desolder the stub from the feed pipe elbow, once the stub was out, I could start to  dry fit the pipework so that the ABV exit pipe was directly inline with the return from the hot water cylinders heating coil.

Once everything was aligned, I removed the head of the ABV so as not to melt anything inside it when I started soldering the fittings.


This is the finished job, I used another compression fitting on the return pipework to make any future ABV replacement easier as the whole assembly can be broken down, something you cant do with soldered fittings.

British Gas replace one of the motorised valve heads and they don’t open the Honeywell junction box to connect the new head wiring, they add an external junction box which looked naff, so I remade the head cable off as it should be done.

The system now needed to be refilled, I coupled a length of 15mm copper pipe with a tundish to the original hand valve and added 1 litre of Fernox Protector F1, once done the pipe was removed, valve closed and a screw cap was fitted.

Mine is a closed system with no head tank, a filling loop from the cold water feed is used to add water and pressurise the system, as I knew there would be a lot of radiator venting, I installed a water pressure reducing valve inline with the double check and isolating valve already installed, this allowed me to set the filling pressure at 1.2bar and leave the valve open, rather than continually repressurising the system after venting air, this worked really well and saved loads of time.


The picture was taken after all the air in the system was vented and the boiler pressure was 1.4bar and steady with no leaks, the loop was disconnected and capped off until next required.

To keep a beady eye on the the pressure over the nest few days I used a home CCTV system 🙂


The main problems I had was not having all the correct fittings to hand when you have to adapt from the original plan, I started the job on a Saturday morning just in case, and fortunately Screwfix is not too far away and they had everything in stock, including a new 22mm pipe slice as mine had packed it.

One thing which bothers me is that the builder used copper pipe where it can be seen and plastic where it can’t, this means that as your cutting pipe, it starts to turn inside the transitional coupling!!

I hate with a passion plastic fittings and have little confidence in them, fingers crossed they will last the test of time.

Sonoff POW – Power Measuring WiFi Switch

Sonoff POW is a WiFi switch with the added facility of monitoring power consumption to the load it switches also it can run trends over time and give instantaneous readings.

I currently use a Belkin power meter inline with my home network UPS so the Sonoff POW is a great addition enabling remote monitoring.

The first job was to attache the IEC plug and socket to the Sonoff POW, I had a small IEC extension cord which I simply cut in half and used that.


Stripping the cable back, I used bootlace ferrules on the wires going under the spring connection terminals for a neat job.


Once the connections were made, the lid was fitted which has integral cable grips to keep the cable from being pulled out.


Making sure that the socket is used for the Input and the plug for the Output, I powered the unit up and paired it with my iPhone and the internet.


To connect to the UPS, I simply unpluged the IEC plug suppling the UPS and placed the Sonoff POW inbetween, using the plug from the Sonoff POW output to reconnect to the UPS and thats it!

in line monitoring

The reading from the Sonoff POW and the Belkin seem to tally up, so well pleased, regarding the On/Off switching function, I will be using this test the operation of the UPS by simulating mains failure, the Sonoff App software allows for a detailed schedule to be created, so may well automate this as some point.

Sonoff Basic Voltage Free Relay Changeover Modification

What is Sonoff –

Home automation is “The Internet of Things”. It simply means the way all devices or appliances are networked together to provide customers with a seamless control over their home equipment.

Sonoff is an affordable device that provides users with smart home control. It is a WiFi based wireless switch that can connect to a wide range of appliances. Sonoff transmits data to a cloud platform through the WiFi router, which enables users to remotely control all the connected appliances, via the mobile application eWeLink. The cloud server of Sonoff is Amazon AWS global server.

Sonoff makes all home appliances smart. As long as the mobile has network, users can remotely control the appliances from anywhere at any time. Another feature available is to set timing schedules for the appliances, which can include countdown, scheduled on/off, and can thus, help users maintain an easy life.



The unit I needed to modify was the Sonoff Basic, this is a simple WiFi enabled unit which will switch 230v on or off, however, the application I needed was for it to switch a set of voltage free contacts, as these cost less that £6.00 each, its worth a go with the soldering iron.sonoff

The unit is very compact and before starting, I paired it with my mobile phone and checked that it worked correctly.

Sonoff open

The top simply clips off the base and the PCB comes apart without any fixings after cutting the paper security seal.



The relay has the Sonoff sticker on it and the mains is switched through the relay, the board uses double sided tracks for this.


The relay was desoldered and removed from the PCB, this then allowed access to the tracks which were cut with a Dremel.

bottom cut

The picture shows the bottom of the PCB with the tracks cut from the 230v input and a shorting link to complete the relay switching circuit.

top cut

This shows the relay back in place and the top tracks cut, the modification now allows a voltage free changeover which will be used to bring on my low voltage triggered external lighting.

Lighting Sonoff

Sonoff installed and connected to controller.

Sonoff Power Switching & Hive Light in Workshop

Sonoff Power Switching & Hive Light in Workshop

I’ve wanted to do a few tweaks to the home workshop for a while, and today I finally got round to it.

The easiest job was done first, this was to install an additional light fixture to house a Hive Smart Light, this has been added to the global Group ‘Lights’ in the Hive App, by the simple Alexa command ‘Lights On’ or Lights Off, all Hive lights and sockets with connected lights operate, this is really handy feature should we hear any noises in the night.

The light can also be turned on independatly via the Hive  App or via interfaces to other Apps’ or IFTTT.

hive light

I bought a cheap and cheerful circular light fitting for the Hive light as it’s very easy to wipe clean.  In the application I was using the hive light for, the lamp required an unswitched mains supply.

The besa box Tee above the Exocutor had the ‘loop in, loop out’ wiring for the suspended light, the new fixture was simply fed from permanent live from this and was up and running within 5 minutes.

The second job is something that I have wanted to for ages but the cost of the technology was prohibitive, until now!


The picture above shows my conversion of a garage into a workshop, this was done in 2007, after the walls were lined, the dado trunking and socket outlets were installed, you can make out that I have used Red and White sockets, the Red ones are not switched via a contactor, whereas the white ones are.

white red

Operating any of the three ‘Emergency Off’ latching buttons, will disconnect the sockets and non Red fused connection units.  A Red LED indicator by the bench  illuminates when the Power to the sockets is ON.


The existing arrangement works fine , but I have always wanted an easy remote ‘power off’ ability, as I have had to check on countless occasions if I have left a soldering iron ON, my usual ‘gotcha’ is the compressor ‘kicking in’, in the middle of the night.

With the cost of internet enabled and Alexa compatable WiFi Smart switches coming down to a ridiculous price of £4.39, now was the time to make the addition of remote operation.


To the left of the change-over switch is the consumer unit feeding the Garage sockets via a 20A MCB, a 3A MCB is for the contactors control circuit via the latching stop buttons.

The idea was to install a Sonoff Basic WiFi Smart Switch to switch the supply to the contactors control circuit.


Cables fished in, Left side is the supply to the Sonoff, the Right side is the Sonoff’s switched output.


Sonoff connected and cables dressed in to consumer unit.


Completed job with Sonoff showing link to server established, before starting the work I configured the Sonoff in the house and enabled the power to be ON by default, once this was done I checked that it work in the Garage.

The configuration is very easy and the App is EWelink, also this is linked to Alexa, the image below is a screen shot of the EWelink App.


The blog on the Rig switching is HERE.

Update – 5 Jan 18, E-WeLink servers have failed this means that control of the Sonoff devices is not possible, no time given as to restoration of service 🙁

14 Jan 18 – Service back up and running and all Sonoff devices now working.

Sonoff 4Ch Pro WiFi/Internet Switch Linked to Alexa

Sonoff 4 Channel Pro


I have had an Amazon Dot for a while and use the interactive plugs and lights all the time, one of the plugs is for my Ham Radio PSU, so I have been looking for a relay interface which will work with the Amazon Dot, one of the key requirements is that the relays must be able to pulse on then off.

The Sonoff 4Ch Pro costs ~£25 and has 4 programmable relays including the ability to ‘inch’ a relay (pulse on then off), the reason this is important for me,  is that it allows a momentary trigger to the PLC controlling my automated mast.

The Sonoff 4Ch Pro is well made and can be powered from either the mains or 5 – 24v DC, relays are all voltage free.

The Sonoff App is EWeLink and allows direct control of the relays from anywhere, this App is then linked to the Amazon Alex App to allow voice control of the relays,m if you want to use voice control from your smartphone, Reverb is good.

EWeLink App needs an account setting up, once this is done, follow the instructions to pair with your router.  The default pairing LED flashing sequence did not work for me, I had to keep my finger on a relay button until the blue LED rapidly flashed and then followed the instructions.

Once paired, the blue LED remains steady, after a power down, WiFi locks within 20 seconds.

Sonoff Enclosure

I decided to mount the Sonoff 4Ch Pro in a 220 x 150 x 96mm ABS enclosure (£9.70 eBay), in Visio I drew the cutting stencil and transferred this to the enclosure.

The width of the Sonoff needing trimming slightly to make a snug fit, the get the correct height I packed the unit with 25 x 25mm wood off-cut.


Using a Dremel equivalent, the lid was cut to accept the Sonoff.


The IEC plug and socket stencil was attached to the side of the enclosure, using a scalpel, the cutting pattern was transferred.



Wired Sonoff 4Ch Pro, Relays 1 & 2 momentarily switch +24v as a trigger input to either Raise or Lower my mast, Relays 3 & 4 latch to supply individual IEC outlets.

The Relays and outlets are rated at 10A, the feeding plugtop has the appropriate fuse fitted.


Finished unit tucked behind a PSU, LEDs show that Relay 3 is energized and WiFi is connected.


The label below is the remind instructions on the voice commands (prefixed with ‘Alexa’) and how to change the relay names.

operating instructions

Update –

Had a huge headache trying to get this unit to re-pair once I had done some modifications to my home network and access point, looking through the help forums a large number of others are having the same problem, the solution which worked for was to put the iPhone in ‘Airplane Mode’ and follow the process to pair an Android phone (Touch) and not AP which had worked previously. What didn’t help was an unannounced outage of the European Sonoff servers!

The second issue which came to light was relay 4 would randomly operate, the fix was very simple, press and hold the internal S5 button to erase any pre-enabled RF switches.

Davis 6410 Anemometer Reed & Bearing Replacement (2000 – 2013 version)

Davis 6410 Anemometer

25 October 17 my wind speed sensor failed after 9 years service, the symptom being that the wind speed is always at zero after checking the connection to the ISS is tight and the cable to the anemometer is not damaged.

This is the blog is how to replace the reed switch and test its operation, also while it was in bits, I thought I’d take the opportunity and replace the bearings as well.


Information Sources

Online sources of information relating to replacing the Davies 6410 reed switch –

Parts Used

Magnetic Reed Switch 10mm MKA-10110 100v 0.5A Russia £3.50 for 10 from eBay.

Metal Sheilded Bearing 0.125 x 0.375 x 0.156 Part R2zz £0.85 each from rcbearings.co.uk

Tools Required
  • Pliers
  • Sharp knife
  • Marker pen
  • Phillips screwdriver
  • 1.25mm or 0.05″ allen key
  • Soldering Iron & Solder
  • Magnifing Glass
  • Terminal Screwdriver
  • Glue gun (or similar adhesive)
  • Multimeter or battery & lamp.
Step 1

Remove the vane and wind speed cups to avoid damage.

Undo allen screw, if tight, use penetrating oil first, the screw does not need to come out.

Once the allen screw is loose, the vane is an interference fit, and with a little gentle force, pulls up revealing the potentiometers (pot) shaft.


The shaft is not ‘keyed’ but will have a mark where the allen screw tightened against, when you reassemble, use this to align the vane so the screw tightens in the same place.

direction shaft

I marked the shaft showing the allen screw mark, I also marked the body of the pot in relation to the housing so that when I reassemble everything is in the same position and the wind direction reading will not be out.


Step 2

Using the same allen key, undo the securing screw on the wind cups, once loose, the assembly slides off the shaft with little force.


Put the wind cups and vane in a safe place till later.

Removing the wind cups reveals the reed switch which can only be accessed by removing the pot.


Step 3

Breaking down the arm and releasing the cable, this is important when we come to remove the pot.

Undo the machine screw and slide this out, once the cable has been released from the in-built grips of the mounting bracket, the tube should slide out of the housing.


The cable inside the tube has a crude cable grip made from an off-cut of plastic hose, either use pliers or a wood screw in the center of the hose, and gently tease it out.


The next part is to slacken the two allen screws which hold the wind and direction body to the arm, once done, slide the arm down the cable to give you working room.


Step 4

Removing the pot, this is a push fit and held in place by hot melted indents, these need to be cut away with a sharp knife.



Once the indents have been cut away, the pot will pull out of the housing, NOTEthis is a tight fit, use pliers to hold onto the pot shaft and draw towards you, Warning – I pulled too hard and pulled wires off  the pot as their is not much slack in the wires from the reed switch, it’s not the end of the earth if you do though as I cut them off anyway!

Note red wire snaped as I pulled to hard removing pot.
Step 5

Remove the gunge from the rear of the pot and note which colour wires go where, the red and black fly lead go to the reed switch and these I cut, I also cut all wires to the pot and removed this so I could easily work on the reed switch and bearings.



Step 6

The reed switch is held in place with the same gunge (hot glue?) as is on the rear of the pot, due to aging it had gone brittle, using a terminal screwdriver it was possible to break this up from inside the housing body.


Once glue is removed, the reed switch assemble will slide out.


Step 7

Reed switch replacement, the reed didn’t appear to be visually damaged, only slight rusting. Testing with a meter and magnet, the reed flexed but no electrical contact was made, checks on the circuit board tracks and resistors were OK.


The zoomed pictures make things look easier to handle than they are, the picture below offers some scale.


New reed soldered into position with the contact leafs horizontal to the orientation of the PCB, I also replaced the Red and Black wires from the PCB with more flexible ones.


Once the reed switch excess wire was trimmed, sliding the PCB into the housing body and getting it flush broke the reed.


The cause was the reed needs sit,as flat as possible,inline with the PCB, I had used too much solder and this lifted the reed wires slightly off the PCB.

The picture below is the second attempt where I used minimal solder on the PCB pads and pressed the reed wires onto the pad before using a small amount of solder to connect to the pad. This seems to have worked and allows the PCB to slide into the housing and sit flush once the wires were trimmed.



After sliding  the reed switch in the body, I connected a multi-meter on continuity buzzer setting, sliding on the wind cups and spinning them, this should cause the buzzer to sound once on each revolution.

Once correct operation is proved, remove the wind cups and reed switch assembly, I sprayed the reed switch with a protective coating and put them in a safe place until later.


Step 7

Replace the wind shaft bearing, first the circlip needs removing and retaining for later use, once the clip is off, the shaft can be pushed into the housing.


The shaft and black cap can now be removed.


My model has the brass follower looking from the cup side, other pictures I’ve seen show this to be the bearing with the brass follower inside the body, I reassembled in the same order as I took apart.


To remove the bearing, I left the brass follower in  and used a terminal driver to go through the hole and using it at a slight angle, gently tap against the underside of the bearing, moving around the inside of the bearing and tapping to tease the bearing out of the housing.

The old bearing is in the bag and it is in good condition with only slight signs of rusting.


The new bearing simple pushed into the housing.

Step 8


  • Slide shaft into place and fit circlip, make sure the shaft spins freely, I applied a light oil to the brass follower only.
  • Slide the reed switch into place and making sure that it sits flush, after putting the bearing protective cap on and I then used hot melt glue from inside the housing to secure everything in place.
  • Checking that the cable is still threaded through the arm, pass the cable into the housing ready for soldering onto the back of the pot.
  • Once with wires are back in place, I sprayed a protective coating on the pot and pushed it back into the housing checking that the marks I made at the start are aligned.
  • I didn’t melt fix the pot, the protective costing will act as an adhesive.
  • The arm was then re-affixed and secured.
  • The arm cable grip was pushed back in, check that the fixing hole is clear for the machine screw when pushing the grip back in.
  • Fix vane back on to pot, aligning grub screw with marking on shaft.
  • Fix wind cups onto shaft.

I used a Glaxio Telecom Wall Box RJ11 which cost £2.69 from eBay as a breakout box for testing that the reed and directing pot are working:


My old 6410 is now refurbished and will be stored in the loft until the one in use packs up.

If you need any further information, please contact me.

Davis Wind Speed Sensor Failed

25 October 17 @ 01:24 – Wind speed stopped recording,  when I noticed I checked all the accessible connections, but still no reading, can’t complain, after 9 years its not done to bad!

Reed Switch failed after 9 years, not too bad!

Detailed information on the Wind Sensor is here.

Ordered a new one from Scaled Instruments,  Gainesville, Florida, also I added a couple of other nice to have goodies:

Product Quantity Price
Davis 6462 – AeroCone w/Bird Spikes and Debris Screen With Davis logo 1 $24.50
Davis 7120.031 – Reed Switch for Tipping Bucket 1 $2.70
Davis 6410 – Anemometer for Vantage Pro2 & Vantage Pro 1 $105.00
Subtotal: $132.20
  • Sub Total – £158.69
  • Customs & VAT – £35.90
  • Total£194.59
New Davis 6401 installed 19 Nov 17

Delivery & Installation Progress

  • November 19, 2017 – Installed all tested and working.
  • November 16, 2017 – Tested new anemometer and wind. direction vane for operation before installation.
  • November 14, 2017, 2:00pm – Received and unpacked.
  • November 11, 2017, 10:33am – Paid Customs Charges and Handing fees of £35.90 to release for delivery.
  • November 9, 2017, 11:37 pm 
    Arrival at Post Office
    Your item has arrived at the delivering post office in UNITED KINGDOM at 11:37 pm on November 9, 2017.
  • November 9, 2017, 3:16 pm 
    Customs clearance processing complete
  • November 8, 2017, 11:07 pm 
    Held in Customs
  • November 3, 2017, 10:24 am 
  • November 1, 2017, 2:41 pm 
    Arrived at USPS Regional Facility
  • October 31, 2017, 12:28 am 
    Arrived at USPS Regional Facility
  • October 30, 2017, 4:05 pm 
    Departed Post Office
    ARCHER, FL 32618
  • October 29, 2017 
    Pre-Shipment Info Sent to USPS, USPS Awaiting Item
  • October 28, 2017 Placed Order


General information and status updates.

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