Why is my radiator not working?

Cold at the top, warm at the bottom

That's trapped air. Bleed the radiator with a radiator key until water appears, then check your boiler pressure and top it up to around 1.2 bar if it's dropped.

Warm at the top, cold at the bottom

That's sludge. Rust and debris settle at the bottom of the radiator and block the flow. A power flush clears it from the whole system.

Cold all over

Check the valves at both ends are open. A thermostatic valve pin can stick, so turn it fully up and down a few times. If that doesn't work, the system may need balancing.

Some rooms hot, others cold

The system isn't balanced, so hot water takes the easy route to the nearest radiators. An engineer can adjust the lockshield valves so every room gets its share.

Not sure which it is? Our fault finder walks you through it, or book a visit and we'll take a thermal image of your system.