The problem of cold radiators can have a number of possible causes. When your radiators fail to heat up, work through these solutions to work out what is wrong with your central heating system and fix the problem as quickly and easily as possible.
1. Bleed the Radiators
One of the most common explanations for a radiator feeling cold is that there is air trapped inside it. The presence of air prevents hot water from flowing into the radiator to heat it up.
To fix this problem, you need to open the valve at the end of the radiator using a radiator key or a flat head screwdriver to release the air. Be sure to put a towel on the floor before you carry out this action, as it is likely that some dirty water will bubble out along with the air. Once you have released all the air, close the valve again and wait for the radiator to heat up.
2. Fix Leaks in the Heating System
Sometimes, a leak in the pipe that serves a radiator prevents hot water from flowing into the radiator to heat it up. Look for signs of leaks in the pipes that carry water around your heating system, such as damp patches, discolouration, mould and rust. If you find a leak, turn off the water supply to prevent further water damage and then call a plumber. Do not try to repair the pipe yourself using tape or home pipe repair kits, as these repairs are rarely reliable.
3. Repair the Water Heater
Sometimes, the problem with a home heating system is located in the water heater itself. A fault in the water heater could mean that it is not capable of producing enough hot water to serve all the radiators in your home. You might notice that the hot water you use for bathing is only lukewarm or that the water supply turns cold during your shower. If you experience these kinds of problems, ask a plumber to service your water heater.
4. Replace the Water Heater
If your water heater is very old, it might not be possible or practical for a plumber to carry out a long-lasting repair. In this case, you would need to replace the water heater with a newer model. Ask your plumber to recommend a heater that offers a high level of energy efficiency to keep your heating bills low.