Tado and Vaillant boiler

[Sohail Ahmed]

Hi guys

I am trying to figure out what is wrong with my Tado smart thermostat install.

The boiler is a 837 ecotec plus

The picture shows the wiring on the boiler side. This is how the engineer had wired up my old thermostat a vaillant vrt350.

The picture shows the wiring on the tado thermostat.

The manual states it don't matter which wire goes to the + Or -. I have tried it both ways so brown to + on both sides still the same issue exists.

I can call for heat on the tado app and the testing seems to suggest all is working correctly. The phone app is communicating with the thermostat. However the issue is the radiators get warm even when heating is off on the Tado app.

Have I wired it wrong or do I have a faulty thermostat?

Thanks

 

[picasso]

The tado is not compatable with the ecotec when trying to use opentherm, only vaillants own controls will work as you have found out, I think there is a bit of hardware you can use to marry your tado to the ecotec (Vr33 ?) but I have never installed one.

 

[Dan Robinson]

Don't forget your 26.9 checks when you've finished messing with your boiler

 

[Sohail Ahmed]

Thanks for the help guys