First things first: Diagnose the issue

Firstly, ascertain whether the problem is limited to one radiator or is affecting your entire heating system. To do this, simply turn your heating on to check whether each of your radiators is warm or not. Once you have performed this step, you should take the relevant course of action depending on your findings. Here’s what to do if...

...None of your radiators are working

If none of your radiators are working, you can safely assume that the root of the issue lies in the whole heating system. You can address this in the following ways:

1. Check your boiler

Ascertain whether your boiler is functioning correctly by looking out for signs that it is healthy. If you discover that your boiler is making strange noises or is displaying an error message, try resetting it. If this still does not work, you may need to call in a professional to help you out. If your boiler appears to be healthy, try checking its settings. Boiler settings can vary significantly depending on their make and model so it is important you check the user manual to ensure that it has been calibrated to suit your needs. It may not be set for both heating and hot water, for example, or it may be in a special mode designed for warm weather. Alternatively, you may have set the timer incorrectly. There are plenty of possibilities so make sure you read any user instructions very carefully.

2. Bleed the heating system

If you find that a number of radiators are cold then there may be a significant amount of air trapped in your heating system. Fortunately, this can be easily solved by bleeding your radiators. To bleed your radiators, you will need to start by figuring out which radiators are colder. The colder the radiator, the more air will be preventing water from flowing into it. You will also need a radiator key. These can be bought cheaply from most homeware stores if you do not already own one. Once you have located a key, fit it onto the radiator valve and slowly turn it until you can hear the release of air (it will sound something like a hiss). As soon as this sound stops or water starts to come out, you should quickly turn the valve back to its original position. You can then repeat this for all of the cold radiators in your home.

...If only one radiator is not working

If the problem is only affecting one radiator, you should be able to address it yourself. Start by checking that it is actually turned on. It may sound obvious, but failing to realise the radiator is turned off is a very common mistake! If it still does not get warm, try the following measures:

1. Check your thermostatic valves

If the whole radiator is cold, there may be an issue with its thermostatic valves (the devices which control water flow in your radiator). Start by removing the head of the valve and checking whether the pin inside it can move up and down. If it is stuck, it probably needs to be replaced and you will need to purchase a new one.

2. Bleed the radiator

Sometimes, air bubbles in the heating system only affect one radiator. If this is the case, it can be bled in the same way as in the instructions above or watch our video

3. Clean out the insides of the radiator

If your radiator is cold at the bottom, it may be suffering from an unpleasant build-up of sludge within the system. Indeed, this sludge tends to be heavy so will sink towards the bottom of the radiator. To clean it out and fix your radiator, you will need to turn off your heating system and turn off the radiator valves to separate it from the rest of the system. You can then bleed it, drain it and remove it in order to clean out the offending material. It can then be replaced and your system turned back on.