My radiator isn’t working! Here are some possible explanations, and what you need to do 

There can be several reasons why your radiator is not working correctly. The list below presents the most common causes and what you should do to deal with them.

Air trapped in the radiator

Does your radiator feel cold in places, even though it is on? This may be caused by air in your radiator. Air trapped in your radiator can prevent the hot water from circulating efficiently. The solution is to bleed your radiator. Bleeding radiators is a relatively simple process which you can generally take care of yourself.

How to bleed radiators

Problems with the thermostat

If your thermostat is not working or if it is incorrectly set, this can prevent your radiator from heating properly. Try adjusting the setting on your thermostat to check whether this produces the desired changes.

Some indications that there may be problems with your radiator thermostat:

• Uneven temperatures: If your thermostats are set to the same value, but it is noticeably warmer or colder in certain areas, this may indicate that one or more thermostats are not regulating the temperature correctly.
• Radiators do not heat to the set temperature: If the temperature in the room does not match the temperature set on the thermostat, this may indicate that the radiator thermostat is not working.
• Constant heating: If your radiators continue providing heat, even though the temperature in your home is higher than the temperature set on the thermostat, this may indicate that the thermostat is defective.
• No reaction to changes: If you change the setting on your thermostat but cannot feel any change to the heating in your home, this may indicate that the thermostat is defective.

In some cases, the solution may be as simple as replacing the batteries if your thermostat is battery-powered. In other cases, you may need to replace the thermostat itself.

Circulation issues

If the pump in your heating system is defective, this may prevent the hot water from circulating correctly to the radiators. In that case, it is a good idea to call in a professional to check your pump and repair it if necessary. Here are some indications that the pump may be the problem:

• If none of your radiators heats up even though the boiler is working properly, this may indicate a problem with the circulation.
• Uneven heating: If some of your radiators are hot while others are cold, this may indicate a circulation issue.
• Noise from the system: If you hear unexpected or unusual noises coming from your heating system – especially from the pump – this may indicate a circulation issue.
• Age of the pump: If the pump in your heating system is old, there is a good chance that it may be causing the circulation issues.

Blocked or damaged pipes:

If the pipes to your radiators are blocked or damaged, this can prevent hot water from reaching the radiators. You will need to call in a professional to deal with this sort of problem. Here are some indications that the pipes are the source of the problem:

• Only some radiators are working: If a few of your radiators don’t heat up, while others are working fine, this may indicate problems with the pipes leading to the cold radiators.
• Unusual noises: If you hear unusual noises from your pipes – knocking or bubbling noises, for example – this may indicate that a pipe is blocked.
• Leaks: If there are signs of water leaking from your pipes or radiators, this may indicate that the pipe in question is damaged.
• Reduced water pressure: If the water pressure in your heating system is too low, this may indicate that one of your pipes is leaking.

Sludge in the radiator:

Sludge and deposits can build up inside your radiators over time, eventually preventing the hot water from circulating correctly. This may result in your radiators feeling cold, especially at the bottom. A professional can flush your heating system to remove any sludge that may have built up. Here are some indications that unwelcome sludge has built up in your radiators:

• Cold at the bottom: If the bottom of your radiator is noticeably colder than the top, this may indicate a build-up of sludge. Sludge and deposits have a tendency to collect at the bottom of the radiator.
• Noise from the radiator: If you hear knocking or bubbling noises from your radiator, this may indicate that sludge has built up in it.
• Reduced efficiency: If your radiators generally feel less warm, of if it takes them longer than usual to heat up, this may indicate that they contain sludge.

Still unsure what’s wrong with your radiators?

Many symptoms of problem issues are quite similar. If you are still unsure why your radiator isn’t working properly, try carrying out the most basic and straightforward repairs first. For example, start by bleeding your radiators. If the problem persists, move on to the next possible cause.

Look out for any additional symptoms that may help pinpoint the cause of the problem. For example, if only one radiator is not working, it is more likely that the problem has to do with the pipes leading to that particular radiator, than with the thermostat and the pump.

If you cannot work out why your radiator is not working, the best move is to call in a professional. A plumber or a heating technician should be able to diagnose the problem and suggest an appropriate solution.