Swap a worn or stuck thermostatic radiator valve head for a new one without draining the system or calling a plumber.
RV-01Check the valve type and buy a matching headTRV heads are not universal. Look for a brand name on the old head (Danfoss, Drayton, Honeywell, Myson and others all differ) and note whether it screws on with a collar or clips on with a small side clip. Buy a replacement head to match, or a universal head if the packaging confirms it fits your valve body.
RV-02Turn the heating off and let the radiator coolTurn off the central heating at the thermostat or boiler and wait about 30 minutes until the radiator is cool to the touch. Turn the TRV head itself to its highest number first, so the valve pin inside is pushed out and easy to check later.
RV-03Remove the old headFor a screw-collar type, hold the valve body still and turn the collar behind the head anti-clockwise by hand until it comes free, then pull the head off. For a clip type, look for a small plastic clip on the side or underside, push or slide it to release, then pull the head straight off. Lay an old cloth under the valve to catch any drips.
RV-04Check the valve pin moves freelyWith the head off, you'll see a small metal pin sticking out of the valve body. Press it gently with a fingertip; it should move in and spring back out on its own. If it's stuck solid, a new head alone won't fix the problem — the valve itself needs freeing or replacing, which is a bigger job.
RV-05Fit the new headLine up the new head with the valve body — most have an arrow or flat edge to match up. Push it on firmly and straight, no wiggling from side to side. Screw the collar back on clockwise until snug, or push the clip back into place until it locks.
RV-06Set the temperature and testTurn the new head to your usual setting, around 3 on most dials for a normal room. Turn the heating back on and check the radiator warms up evenly across its whole width within 15-20 minutes. Check around the valve collar for any dampness once it's warmed through.
RV-07Tidy upWipe down the valve and radiator with a dry cloth. Bin the old head, or keep it briefly in case the new one is faulty and needs swapping back for comparison.
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