If you have thermostatic radiator valves (TRVs) and all your radiators are hot except maybe 1 or 2 that are cold, try out this simple tip immediately.
Go to the toolbox and pick up a hammer (preferably a small one) and/or long-nose pliers – and then:
- Head to a cold radiator
- Unscrew TRV base (red circle on photo)
- Squirt with WD40
- Gently tap with a hammer to ease up the metal pin
- Screw TRV back on
If the pin in your TRV had been faulty, hot water should now be flowing back into your once-cold radiator, as easy as riding a bike. You have likely saved yourself a large amount of money in boiler engineer call-out fees!