Tado TRV issue!?

Hello, I’ve recently had a radiator replaced including the valves. The TRV has been mounted on the return side of the radiator and not the flow side. The valve is bi-directional. The issue I’m having is that when heat is called for, it takes a very long time for the radiator to get hot and the valve where the TRV is mounted remains lukewarm. Is this a case of the new valve not opening fully!?


  • As a test unscrew the Tado TRV and its mounting base from the valve (dont unclip the TRV from its base or it will want to calibrate again). This will ensure the spring pin is fully up - do a manual test to check that the spring pin moves up and down freely.
    Dial up the temp to max for a different TRV that you know works. Both radiators should now get hot. If the problem one doesnt you should check how far open the valve at the other end of the radiator is (the lock shield valve).
    On a balanced system it is always worth counting the number of turns it takes to close the lock shield valve so that it can be reopened to the same ammount. If the radiator has been replaced this probably hasn't been done.
    Try opening the lock shield valve some more.

    If the radiator gets hot without having to change the lock shield setting then the problem would appear to be with the Tado TRV.
    Try swapping the TRV with a different one to see if the problem moves with the TRV.
  • Thank you for the reply. I’m away at present but will try this as soon as I’m home. My dad fitted a standard TRV and it still seems to be an issue, so potentially the lock shield might need to be opened more as you’ve suggested. I’ll come back and update asap, thanks.
  • If the problem still exists using a standard TRV head then it is either the spring pin is stuck down - probably worth replacing the valve - or the lock shield is closed down too far.
  • Hello… so I’ve removed the TRV’s and the pin is functioning as it should… moves quite freely when pressed.

    The radiator is almost too hot to touch at the incoming and barely hot on the return. Does the lock valve need opening more!? Is there a risk of opening it too much!?

    The radiator is fed by 10mm pipe as it’s an. Add on from the previous owners, should that make a difference with how long it takes to heat up the radiator!?
  • @Kidnap86

    If your radiator is not getting "HOT" and is only getting "LUKEWARM" then possibly the Lockshield valve is open too much.....this would allow the heated water to pass through your radiator too quickly and therefore the heated water can not actually pass on the heat to your radiator. So shut down the Lockshield valve.

    Just a thought.

  • It’s a lot of trial and error but will try shutting it down somewhat. If it was open too much … wouldn’t the LSV get hot get hot either way? This gets hot when the radiator is finally hot. Every other radiator gets crazy hot and fast. Just this one takes time.