Tado wired thermostat not communicating with my boiler

TadSad

I have a Worcester Bosch Greenstar 37 CDi combi boiler.

My installer has just connected a Tado Wired Thermostat Starter Kit V3+. ALl of the wifi pairing is fine, and it's communicating with the app and the Smart Radiator Thermostats fine. The only (critical) problem is that the Wired Thermostat isn't communicating with the boiler - either to turn it on or off. The installer has tested the electrics and found them fine without the Tado (plus my previous thermostat worked fine), but he says only 160v are being passed to the boiler by the Tado Wired Thermostat, so he's not surprised that it isn't able to power the boiler up or down.

I see there are quite a lot of posts on here about Wired Tado Thermostats not communicating with boilers, and the only helpful sign was someone saying that Tado had pushed a change to the configuration.

Other than it being very disappointing and having wasted a lot of time, it's not a massive problem at the moment that I have no heating as teh weather is warm. However, we do need to get this working after investing =nearly £400 in the Tado system.

All advice welcome.

Thanks

johnnyp78

Check your thermostat is set to the right mode. Instructions here. Sounds like the installer has installed yours as either potential free relay or 230v but I couldn’t guarantee that. https://cdn.brandfolder.io/607DGEMS/as/7k4rssnm8hbmr6mjf94qmck/104210-DIGITAL-ST01IB01-INSTALLER_MANUAL-TA-EN-00-V3.pdf

The 160v comment is confusing - ask your installer how he’s wired it to make sure. If he’s wired it digitally the configuration will need to be changed on the thermostat.

TadSad

Thanks, I've now decided that we just needed to be more patient - it takes 2 mins for the boiler to turn off after the app or thermostat tells it to. As it fires the boiler up within a few seconds, we had expected the same response the other way, but I see that the instructions say to wait 3 minutes, so that was where we were going wrong.

TadSad

Update: Installer has confirmed it's wired as a 230V Relay , which the Instructions say is the default factory configuration. Is this wrong?

Further testing has revealed very variable delays to it turning the boiler off - current one still not off after 4 mins.

johnnyp78

Sounds like it's working as it should do. If the delays get any longer you might need to look into it but Tado should be working like this - because it can't modulate the boiler water temperature, with a relay installation it will attempt to modulate by cycling the boiler - turning the heat off and on at variable intervals.