Rad not heating despite below temp

I have tado smart trvs fitted on the 4 bedroom radiators - but downstairs the radiators are dumb trvs. With this setup I know and understand that when any one one of the bedrooms calls for heat the downstairs radiators will heat up. And that’s fine. However I have situations where on occasions a bedroom trv will be calling for heat but not getting warm - despite the boiler firing up and the downstairs radiators getting hot - this means the bedroom never reaches the desired temperature and the downstairs just gets too hot (albeit I have the dumb rads down low) In order to force the boiler to turn off I have to manually intervene and turn down the bedroom temperature which then triggers the boiler to turn off. What’s wrong here? I’m confused. It seems to be when the room is within 1/2 and 1 degree below the desired temperature but doesn’t get warm therefore doesn’t reach the temperature and hence the boiler stays on and rads downstairs are boiling. I’m confused. Any advice appreciated thanks. Hopefully my description makes sense.


  • Sounds like your Tado trvs aren’t calibrating properly to the radiator valves - you can ask Tado support to adjust the amount they open when there’s only one bar of heat required.
  • Thanks for the quick response. Sounds like a plan. I’ll drop them them a message. I’ll update this thread with what happens.