If your radiator isn’t working properly, it’s usually due to one of several common radiator problems.
Many of these problems can be solved by home residents, without having to call a plumber or boiler engineer.
Radiator not getting hot
If your radiator isn’t getting hot, make sure that the thermostatic valve – the one with the adjustable plastic cap – is open.
If it is, check to see that the lockshield is open. To do this, you will need a small pair of adjustable grips. Whenever you open or close the lockshield, make a note of how much you’ve moved the valve. This will save you from having to balance the radiator.
It could be that the valves have a jam or blockage, or that there is a blockage elsewhere in the system.
Radiator cold at the top
If your radiator is cold at the top but hot every else, it’s most likely due to air trapped inside.
You can easily remove this air by bleeding the radiator. Turn the heating off and allow the system to cool down. While holding an old towel or cloth to catch any water, open the bleed valve with a radiator bleed key and the air should come hissing out.
If you have several radiators with this problem, you may want to read the following article: how to bleed the radiators.
Radiator isn’t working and there’s no hot water
In this case, there’s most likely an issue with the boiler. Check to see that the power supply is OK and that the programmer or thermostat is actually calling for heat.
If you have a combi boiler, check the pressure gauge. It should be between 1 – 1.5 bar when the system is off. If it’s less than this, the boiler won’t come on at all.
You can easily restore the pressure yourself: click here for the article on how to fix low boiler pressure.
Radiator cold at the bottom but hot at the top
This is usually due to the build-up of sludge inside the radiator.
Sludge is a black substance that is produced when oxygen in the water reacts with the metals inside your heating system.
This problem is a bit trickier to solve yourself, but it’s not impossible. You can remove the radiator from the wall and flush it out. Click here for our guide on how to remove a radiator.
However, if there’s sludge in one radiator, there’s probably sludge elsewhere in yourself. It’s probably a good idea to remove the sludge from the whole system by getting a power flush.
Make sure to add central heating inhibitor to stop sludge from forming again. Click here for our article on how to do that.
Radiator making strange noises
Most radiators make some noise – for example, you may hear a faint sound as water flows through it. You may also hear a clicking sound – this is just the sound of the metal expanding or contracting as it heats up or cools down.
However, if you hear grinding, banging, thumping, or gurgling sounds, it may be due to air in the system, improperly secured pipes, or the pump speed is set too high.
For more on this topic, check the following article: radiator is making strange noises.