Other rooms overheating when reheating the living room

I noticed a strange behaviour from my Tado temperature graphs.

Whenever Tado is "reheating" the living room, two of my other rooms heat up despite the individual smart knobs are set to a lower value.

The said two rooms did not call for heating. However, their temperature rose up to 19.3 degrees, even though thermostats were set to 16 & 17 degrees. Only the living room was expected to heat to 19 degrees.

Other rooms, except the problematic ones mentioned above, maintained their expected temperature (16 and 17 degrees).

All rooms except the living room have Tado smart radiator knobs.

Questions:

  1. Which steps would you take to troubleshoot the issue if you encountered this problem?
  2. Is it possible that the thermostatic valves are stuck?

Any help/ idea to troubleshoot this issue is much appreciated.

Answers

  • Most likely a problem with calcification causing the pin to stick or the valve seat not to seal properly. Use a coin to repeatedly push the pin down hard and release. WD40 will temporarily ease a sticky pin, but it's not a long term fix. Remount the valve head and it will recalibrate. Ultimately you may need to replace the valve body.

  • Thank you for your suggestion.

    The valve didn't seem to be stuck when I pushed it, but I lubricated it with WD40 anyway.

    It seems to be only partially effective.

    Someone also suggested that water temperature could be too high. I'm going to try lowering the water temperature as well.

  • If they are big radiators in small, well insulated rooms it could be that they are getting really hot, then shutting off but still heating the room. Does it peak and then drop to below the 16/17c then peak again, or sustain at around the 19c for the duration of the Lounge heating cycle?