Helpdesk for tenants

Heating » No heating » Radiators not hot enough

Radiators not hot enough


If a radiator remains cold (when the central heating boiler is working properly) or just the top of the radiator remains cold, this suggests there is an airlock in the radiator. An airlock in the radiator is always at the top and will block the water flow. This can be solved by bleeding the radiator.

Resolve it yourself

You will need a radiator key and an old towel or cloth. Radiator keys are available at any hardware store.

  1. Turn off the heat and wait for the radiator to cool down. An active system can introduce more air into the system.
  2. Use the radiator key to open the 'bleed valve'. It's located at the top of one end of your radiator.
  3. Hold the cloth under it and let the air escape very slowly. It will probably hiss and occasionally a drop of water will come out. You should continue until a trickle of water comes out. This means the air has left the radiator.
  4. Close the bleed valve with the radiator key.If air escapes, usually the pressure in the system drops.

Always check the pressure at your central heating boiler after bleeding a radiator. If necessary, please refill your boiler.

Radiator knobs

If after bleeding the radiator remains cold, it could be that the radiator knob is stuck. This is common with thermostatic valves after a period of inactivity (e.g. after summer).

  1. You can remove the knob and you’ll see a pin going into the radiator.
  2. Press this pin several times with the back of a screwdriver until it moves smoothly back and forth (only a few millimetres!).
  3. Reinstall the knob.

Repair request

If none of the above gets the heating working properly, please leave a repair request.