Radiator cold at the top? How to bleed it., by BeeXpress on YouTube. 1 min 47 s.
- Video length
- 1 min 47 s
- Time to do it
- 10 minutes
- Difficulty
- Easy
- Steps
- 9
What you need
Steps
Switch off the heating and let the radiators cool completely. Bleeding a hot radiator risks scalding water and makes the job harder.
Find the bleed valve at the top corner of the radiator. It is a small square or slotted screw inside a round nut.
Put the cloth under the valve and hold the small container just below it to catch any water.
Fit the radiator key onto the valve and turn it anticlockwise, about a quarter turn. Do not unscrew it fully.
Listen for a hiss as trapped air escapes. Keep the key steady until the hissing stops and water starts to dribble out.
Close the valve by turning the key clockwise until it is snug. Do not overtighten it.
Wipe up any drips with the cloth and repeat on each radiator that feels cold at the top.
If you have a pressurised system, check the boiler pressure gauge. Top it up to the level in your boiler manual if it has dropped.
Turn the heating back on and check that each radiator now heats evenly from top to bottom.
Tips and common mistakes
Bleed radiators when the heating is off and the metal is cold to avoid burns.
Keep the key straight and turn gently so you do not damage the valve or lose the key inside it.
If a radiator stays cold or needs bleeding often, call a heating engineer to check for air being drawn in.
Never drain large amounts of water from the valve. A few drips are normal, a steady flow means the valve is open too far.
Questions
What if I don't have a radiator key?
Some valves take a flat-head screwdriver instead. Check the shape of the valve first, and buy a radiator key if it is the square type.
Why is my radiator still cold at the top after bleeding?
Air may still be trapped, so try bleeding it again once the system has run. If it keeps happening, the system may need a professional check.
Do I need to top up my boiler after bleeding?
Only on a pressurised system, and only if the gauge has dropped below the recommended level. Follow your boiler manufacturer's instructions.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
