How do I know if I need to bleed a radiator?
If your radiator has cold spots, then there’s likely to be air trapped inside – so you may need to bleed it. Trapped air will cause your radiator to have cold spots, reducing the efficiency of it. You can bleed a radiator yourself, and it can vastly improve the efficiency of your entire heating system.
What you will need
- Radiator key
- A cloth
- Safety Gloves
Here’s how you can bleed a radiator in 5 easy steps!
- Turn off your boiler
First, switch off your boiler completely, so there’s no chance of you getting splashed. For safety, we recommend wearing gloves
- Locate the radiator bleed valve
Every radiator has a bleed valve at one of its corners, identifiable by a square bit in the middle of the round plug. They’re turned by specific keys, called ‘radiator keys’, which you can buy at any good DIY shop.
- Open the valve with the radiator key and release air (until water appears)
Holding a rag or cloth under the valve (to catch any water that may be released), use the radiator key to turn the valve anticlockwise about a quarter of a turn (not too far) – you should hear the trapped air hissing as it’s being released.
- Close the Valve
Keep the key on the valve, and once the hissing stops and the first dribble of water appears, close the valve tightly.
We’d recommend having a bucket handy to catch spurting water in case you open the valve too far.
If no water or air comes out when you bleed the radiator, then the valve could be blocked with paint. Close the inlet and outlet valve at each end of the radiator, then remove the screw from the center of the bleed valve.
Clear the hole with a piece of wire, and reopen one of the radiator valves slightly to eject some water from the hole.
Close the radiator valve again and refit the screw in the bleed valve. Open both radiator valves and test the bleed valve again.