Mixing TRVs and Thermostat

Phil_Taylor

I recently installed the starter kit with a smart thermostat in my lounge with the TRV left fully open. All other rooms were left with conventional thermostats. Everything worked well.

I have now added 3 Tado TRVs to the remaining rooms. I now have the problem that even if the room with the thermostat in is to temperature or above, but another room is cold, the boiler fires up, causing the room with the thermostat to overheat.

Is there a better way to solve this, other than setting the conventional TRV in the room with the thermostat in to the max temperature I would want to heat this room to?

Secondly, should I be setting the offset on the TRVs when the room is cold, or when the heating is on?

wateroakley

@Phil_Taylor It'll probably behave just the way you describe, as all rooms can now call for heat and your lounge rad will always heat up when the boiler is on. The way to solve this is to fit a Tado SRV on the rad thermostatic valve in the lounge where you have the room stat, they will work together. When the room temperature fon the stat is reached, the system will tell the SRV to turn off the rad valve. You could check this out by swapping one of your 3 Tado SRVs for the TRV head on the lounge rad. (If you have added thermostatic valves on all rads, check with your heating engineer if you need a 'bypass' for the boiler).

We adjusted the offset for one SRV (on a rad behind the sofa) to reach the required room temperature, checked against a digital thermometer. It took a couple of attempts of successive approximation to get it right. It is now correct at the 'set temperature'. When the heating in the room has been OFF overnight, our Tado SRV reports the room is cooler than the digital thermometer. I put that non-linear effect down to the sofa in front of the rad and SRV.