How to Bleed a Radiator

Radiators need to be regularly bled of excess air or gas to ensure they’re performing to maximum capacity. It may seem the wrong time of year to think about your heating system, but sorting it out now will ensure your radiators are ready for use when you switch them on again.

You may prefer to have this done by professionals, and if you’re looking for London plumbers or a handyman in London, Handy Squad would be delighted to help. It’s quite possible to bleed your own radiators, though, if you follow a few simple steps.

Bleeding your Radiators

1. Turn on your you heating system and wait until all your radiators have fully heated up. Unless you’ve built up the pressure inside, the air won’t come out when you open the valve.
2. When your radiators have been on for a while, check each one individually to find out if it’s heating up properly — but be careful not to burn yourself. Cool spots are most likely to be found near the top of the radiator, marking where there’s a build-up of air or gas.
3. Radiators with cool spots need to be bled. Turn off the heating, so you can carry out the process safely, and find the valve at one end of the radiator.
4. You’ll need either a radiator key (available from any hardware shop or DIY store) or a flat-blade screwdriver. Either fix the key to the square valve, or insert the screwdriver into the groove.
5. Have two cloths ready, one to hold the key or screwdriver, the other to catch any water that escapes. Turn the screwdriver or key slowly anti-clockwise. If you hear a hiss, that means the gas is escaping.
6. When the gas is all gone, water will start coming out — usually a dribble if you’ve used a key, or a spurt if you’ve used a screwdriver. Turn the valve clockwise immediately to close it.
7. Look at the gauge on the boiler to check pressure. If it’s low, use the “filling loop” to fill up — this will be a lever or tap on your boiler, and should be clearly marked in the manual.
8. Repeat steps 1 and 2 to make sure all air has been eliminated.

Make Your Heating Efficient

Bleeding your radiators will make a big difference to the efficiency of your heating system, but there are other things you can do, from putting insulation foil behind your radiators to buying a radiator booster. If you need assistance with any of this, Handy Squad offers help with plumbing in London.