Radiators, who’d have them? They seem to be more trouble than they're worth sometimes…or at least this is what you'd imagine sometimes. A night without radiators and you'll soon be blessing them as one of the greatest inventions ever made – it’s freezing without radiators!
Still, from time to time, they do play up, and it can be incredibly frustrating. Sometimes, the hardest part is working out what the problem is. Today, we have created this troubleshooting guide to help you work out why your radiators might be cold. If the system is working correctly, and the radiators are cold, or partially cold, then one of the following troubleshooting options should provide the answer – if not, it’s time to call in the experts.
The Top of the Radiator Is Cool
This is such a common issue that the solution is built into the radiator. Radiators get cold at the top when there is air in the system. The air loses heat much faster than the water, and so wherever there is an air pocket, there will be a cold patch, and because air is lighter than water, it will rise to the top of the radiator eventually, hence making it cool at the top.
If the radiator is cool at the top, then it invariably means that you will need to bleed the radiator. To do this, you need your bleed key. You simply put the key in the valve and turn it slowly until you hear a hiss, you keep this up until a bit of water leaks out, and then you close the valve. This should sort the problem
The Bottom of the Radiator Is Cool
A radiator being colder at the bottom is worse news. It indicates that there is debris in the system. This is harder to address. The first thing you can do is install a magnet trap and see if it collects the debris. If you continue to have issues, it means that you will need to have the system flushed. To do this, you need to call in the experts. Flat panel radiators tend to be less susceptible to this sort of issue than designer radiators or column radiators, so if it is a common occurrence, you should consider swapping out your radiators.
The Radiators Are Warmer Upstairs Than Downstairs
If you're radiators are warmer upstairs than downstairs, it can indicate that there's a problem with the balance. You simply need to repressurise the central heating system. There are plenty of articles and videos that can show you how to do this, but if in doubt, call out the experts.
One Radiator Is Cold But the Others Are Warm
Finally, if only one radiator is cold, it indicates a problem with the valve. Check to see if it’s stuck, and if it is, then apply a little WD40 and wiggle the pin until it’s released. With most flat panel radiators, you will have a TRV valve. You will need to remove the head to locate the pin.