What are some common radiator problems?

Finding a cold spot on a radiator, or even the whole radiator itself is cold, can be a daunting prospect - it's both annoying when you want to heat your house up, and worrying because it makes you wonder what the problem is. Understanding what some of the most common causes of cold radiators are can give you a convenient checklist to work through when you're diagnosing the fault.

Wrongly set thermostats, faulty timers, closed radiator valves, air pockets and blockages in the system and general circulation errors are all your primary candidates for a cold radiator - fortunately, none of them is difficult to rectify.

What's behind your radiator malfunction?

An issue with your boiler or your central heating system, in general, could be the cause of your cold radiators. Where the radiator is, however, and the way that it's not heating up can tell you a lot about the fault that's causing it.

Cold radiators in certain parts of the house

If you notice only certain radiators in your house aren't heating up, it could be down to an issue with one of your central heating zones. Central heating works by pumping a constant flow of hot water through the pipes to the radiators, then back to the boiler to be heated again. Often this system is broken up into different "zones" within the home, which could be where your fault lies.

An individual radiator isn't working

You might notice that only one radiator in the house isn't heating up. This could be down to the valves being set incorrectly. Check the sides of the radiator to ensure that both of the valves are open. If they are open but the radiator still won't heat up, the valves are likely blocked. This is where you should be contacting a Gas Safe registered heating engineer to come and rectify the problem.

Cold radiators only upstairs

If your radiators are only cold upstairs, it could mean the expansion and feed tank in your loft has dried. This is an issue in itself, but usually only happens as a result of a larger issue. However, a simple fix might be the ball valve in the tank has malfunctioned, so rectify this before exploring any other options. You do this by getting to your cistern and clearing out any obstructions you might find in the ball valve, before refilling the cistern - there should be just enough water to make the ball float and turn off the water coming in.

This might be the only issue, and with the cistern properly refilled and ball valve unblocked, the upstairs heating should begin working again. However, it might also be a symptom of a larger issue, so it's worth seeking the services of a professional heating engineer for further investigation, especially if it becomes a recurring problem.

Cold radiators downstairs

When radiators downstairs stop heating up, it often falls back to a problem with your pump, which is not producing enough pressure to push the hot water around the whole heating system. A warm pump is normal, but a hot pump or one that is making any sort of grinding or metallic sound is at the end of its life and needs to be replaced as soon as possible by a Gas Safe registered heating engineer.

Cold zones within a radiator

Sometimes parts of one radiator might be cold. If the middle or the bottom of the radiator is cold, it might mean a blockage. For open-vent systems, a dedicated blockage remover can be bought from your local hardware store, which you can use by following the instructions on the packaging. For a pressurised system, however, contact a heating engineer to flush your system and remove the blockage for you.

Always be ready to contact a professional

In many cases, an issue can be rectified relatively simply - however, if you're not confident in what you're doing, it's essential you seek the services of a professional Gas Safe registered heating engineer. No matter how small the problem is, if you're not sure of each step you're taking, it's highly likely you could cause further damage to your heating system. If you're ever unsure, it's always the wisest course of action to contact a heating engineer who can determine and solve the problem for you. This is far more stress-free, efficient and affordable than risking further damage.