No heating

benpwallis

I've had Tado V3 for years now with no problem. The last 3 days I have no heating, changes within the app register on the thermostat but does not fire the boiler. Manual button press fires the boiler up to then revert back to waiting status.

Things I've tried

-Reinstall App

-Betteries changed

-Remove Home and reinstall devices (bridge and thermostat)

-Power down boiler and check cabling

-Replaced thermostat cabling to boiler to rule out cable issue

-Purchased new Tado V3 and installed, (now reverted as is didnt resolve issue)

All to no effect, Tado says they saw I had some kind of interruption in the configuration 3 days ago and they resolved it but still nothing. I see the firmware did update on the thermostat in the last few days unfortunately not resolving the issue. I've tried a lot as I get one email a day from Tado even though I have no heating 😡

Boiler is intergas HR Eco Combi compact 36,

Wired connection on boiler is

-red cable to connection 12

-Blue to connection 11

Wiring to thermostat is

-Red cable to +

-Blue cable to -

Any ideas?

benpwallis

Additional info.

-Test program on the boiler works fine and heating is provided.

TadoUser2

I posted a few days ago with similar issues, I had to increase my upstairs Wired Thermostat to 25 degrees before the boiler fired.

Weirdly the downstairs Wired Thermostat was opposite, it was well above the temperature set yet it kept clicking on and firing the boiler.

There's something not quite right at the moment as up to a few days ago everything worked well.

benpwallis

Well I can’t keep telling my wife and kids to wear more clothes for much longer, I fear the tado device will soon experience a new type of ‘open window detection’ ;)

policywonk

How comfortable are you with an electrical testing screwdriver and some wires? You can take a few steps to work out whether it is the boiler or the Tado side which is causing the trouble.

Presumably the boiler still has an annual service. How long before that is due? This link Plumbase Manuals identifies the installation guide. Go to pages 31 onwards. Pages 41-42 provide the wiring diagram.

It provides a scheme to check for errors from page 31. You might want to work through that and use it to determine whether there is a boiler logic fault or whether it is arising from the Tado side.

It refers to the fact that it can operate in Opentherm mode, where the following are in place in connector X4:

• Pins 6-7 as a bridge can force the boiler to fire.
• Pins 11-12 - which is where I presume your Tado thermostat is wired in - should control it in Opentherm mode. Is that where is wired?

Connector X3 runs the boiler in dumb mode, if yours was wired that way instead, with pins 1-3 acting as a dumb, mains voltage thermostat. However in order to force the boiler to bypass the Tado wiring, you will need to call the manufacturer's tech team and get their advice on how to force a test. It shouldnt be difficult.

Also, can you, from your app, identify how your Tado Thermostat was configured? Was it in dumb mode, or Opentherm mode?

• If it is set to operate in dumb mode, you should be able to test whether the thermostat has failed by bridging the relevant pins
• If set to operate in Opentherm mode, I suggest you come back here and push for someone who has Opentherm experience to help you. There are a few, including the Tado administrators.

benpwallis

These photos show the connection that has always been in place, for years. A boiler engineer came out today and we (temporarily) wired the thermostat exactly the same way to the boiler using a shorter cable so I can diagnose better. Note after speaking with Customer support they suggested overiding the smart thermostat by connecting both wires to NO terminal. This fires the boiler normally and continuous. I just don't understand how this thermostat (which is a v2 not v3 btw) and the V3 I purchased yesterday are having the same issue but bypassing them has no problem. I don't know how to check the app for opentherm or dumb mode, nothing I can see like this within the app

policywonk

@Emcee . Would you accelerate Tado support on this client? An Opentherm configuration where the boiler fires when your client creates a novolts bridge. This suggests that the thermostat or the app are failing to send the wake up signal and modulate properly.

benpwallis

Thanks. Please note I just tried the V3 unit again but this time wired it to NO and COM terminals instead of + - which the V2 worked on for years. The V3 in this config works as expected by app or manual control. If I reconnect V2 on this config the boiler is always firing and cannot be controlled. It looks to me as if I have a failed V2 unit or Tado have pushed an update which has messed this up. @Emcee i would appreciate some guidance and next steps from someone. Preferably I don’t want to have to keep this V3 unit as I only have it temporarily without charge ;-)

benpwallis

Update: V2 unit IS working in using connections NO and COM. So why after all these years where it’s been working perfectly fine on + and - connection has it suddenly changed? My firmware on the device a few days ago when I first started having an issue was 4x.xx or something and now it’s 54.2 which I understand is the latest. I’m guessing 54.2 only supports this new wiring config? But unsure why it was not working when I had 4x.xx displayed? Beyond me, but for now it seems to have been resolved as I’ve changed the wiring

srichards

The firmware on my v3 (or maybe it's a v3+) says 215.2! Mine is wired in dumb switch mode. I have just changed boiler but kept the old method. Not seen these issues. Both boilers are Worcester ones. I got the wiring options out of this:

https://cdn.brandfolder.io/607DGEMS/as/7k4rssnm8hbmr6mjf94qmck/104210-DIGITAL-ST01IB01-INSTALLER_MANUAL-TA-EN-00-V3.pdf

Emcee

@policywonk the case has been escalated as of today.