Problems with radiators

If the radiator valve leaks...
A radiator leak is often caused by a loose joint. To fix, first switch off the central heating system. If the leak is from one of the valves at either end of the radiator, you may be able to solve the problem by simply tightening the nuts with an adjustable spanner. Use a pipe wrench to stop the body of the valve twisting.

If the joint continues to leak, you may need to replace the valve - call in a plumber if you aren't confident about tackling the job.

The other possible cause of a leak is corrosion to the radiator panel. Although you can buy metal repair resin to plug the hole, it's better to invest in a new radiator.

If the radiator is colder at the top...
If the top of your radiator is colder than the bottom, air may be trapped in the central heating system.

To fix, turn your heating on and use a radiator key to twist the square bleed valve at the top corner of the radiator. You should only need to make about a quarter of a turn anti-clockwise. When the air has been released from the valve, the hissing sound will stop and water will start to drip out. Retighten the valve.

Tip: Always have a cloth ready to catch the drips.

If the radiator is cooler in the middle...
This may be caused by corrosion in the system. Sludge builds up in the radiators and stops the even flow of heat. The radiator will need to be taken off the wall and flushed with clean water before refitting. Once you've removed the sludge, add a pack of corrosion inhibitor to the central heating system, following the maker's instructions.

Log on to The Association of Plumbing and Heating Contractors for more information.