Valve not able to control a radiator

What to do if a radiator valve does not seem to be behaving as it should. Here are the steps to check what may be causing the problem:

• If the room has a blue background on the app, the wireless valve should read 4 and the radiator should be cold. Note that it can take up to 10 minutes for the valve to update if the room has just turned off.
• If the room has an orange background on the app, the wireless valve should read the set (target) temperature on the app. Note that it can take up to 10 minutes for the valve to update if the room has just turned on.
  
  
• If the wireless valve is showing a target temperature above 4 but the radiator is cold, this is most likely to be because the target temperature is set close to the measured temperature in the room, and though the app is orange and the wireless valve is showing the target temperature, the radiator is cold because the wireless valve has decided that the room is close enough to the set temperature and it does not need to add any more heat to the room.
  
  
• If the room temperature is significantly below the temperature displayed on the valve's screen, but the radiator is still cold, then the pin in the valve body (the metal part of the valve, which the water flows through) cannot open properly. It's possible that the pin has become jammed or stuck. To fix this, remove the valve head from the radiator, and with a pare of pliers or end of a large spanner, work the pin on the valve body free. Be careful when doing this as if the valve body is in poor condition, it may cause the valve body to leak. If it's not possible to free up the pin on the valve body, it will need to be replaced. Once the pin is free, remount the valve head. Also see the Installation Guide to see how to mount the radiator valve correctly.

• If the wireless valve is showing a target temperature of 4 but the radiator is warm, this means that the wireless valve cannot control the water flowing into the radiator and this may be because of the following reasons:
  • The valve body may be corroded inside, which means that the wireless valve cannot push the valve shut. This means that the wireless valve needs to be removed from the valve body, and with a pare of pliers or end of a large spanner the pin on the valve body needs to be worked free. Be careful doing this as if the valve body is in poor condition this may cause the valve body to leak. If it is not possible to free up the valve body, then it will need to be replaced. Once the pin is free, remount the valve head. Also see the Installation Guide to see how to mount the radiator valve correctly.
    
    
  • The wireless valve head may be cross threaded onto the valve body. This means that the wireless valve cannot push down on the valve body effectively. To rectify this the wireless valve needs to be removed from the valve body and remounted. Also see the Installation Guide to see how to mount the radiator valve correctly.
    
    
  • If the valve bodies are Danfoss RA-FS type, some times the grub-screw that is tightened up with an allen key is not tightened up enough, and the white adapter ring rises up the valve body; you will see a small gap under the adapter ring. This means that the wireless valve cannot control the pin properly in the valve body. The wireless valve head needs to be put into mount mode and then mounted onto the valve body, so that the white adapter ring is tight up against the valve body. HG - Installing a Wireless Radiator Valve (Danfoss RA-FS thread)