Cold Radiator Troubleshooting Tips

If you discover that one of your radiators is cold to the touch and doesn’t seem to be heating up properly, your first step is to identify whether the problem is limited to one single radiator, or whether all your radiators are affected. Once you’ve determined the scope of the problem, you can begin troubleshooting.

Should you find that all your radiators are cold, it is likely a larger problem with your boiler, plumbing, or pipework. You’ll want to call a professional plumber to come take a look.

However, if the problem seems to be isolated to one radiator, you may be able to fix the issue yourself. This list of common radiator problems and how to repair them will help you get started.

Problem: Top of radiator is warm, but the bottom is cold.
Solution: Excess air may be trapped in the upper portions of the radiator, creating a bubble of cool air that prevents the hot air from rising to the top. You will need to bleed the radiator to expel it.

Bleeding a radiator is very simple. First, turn off your heating system, as bleeding a radiator while the system is active can introduce more air into the radiator. Then use a radiator key (available at any hardware store) to open the radiator valve. You’ll hear a hissing sound as air escapes. Have a towel ready beneath the radiator—water will begin to sputter out. When the sputter becomes a steady stream, you’ll know that all the trapped air has been dispelled.

Bleeding all the radiators in your home regularly can help prevent this problem in the future.

Problem: Top of the radiator is cold and the bottom is warm.
Solution: A layer of sludge has likely accumulated in the bottom of your radiator, which is preventing it from circulating the warm air and heating up properly. To clean it out, you will have to remove the radiator from the wall and rinse it out. Be prepared for water to gush out when you detach the radiator from the wall. Have pans and towels ready to catch the flow of water.

Problem: The entire radiator is cold.
Solution: Check your thermostatic radiator valve to see whether the pins inside the valve are moving properly. You will have to remove the top of the valve to do so. Take the head off the valve and watch to see whether the pins are stuck or whether they are able to move up and down freely. Tap the valve gently to loosen any that are stuck. If this doesn’t solve the problem, you may need to replace the valve entirely.

If after you’ve tried these troubleshooting solutions your radiator remains cold, it may be time to call a professional. Bonfe’s heating repair experts will be able to identify and resolve your radiator woes without delay so that you don’t have to spend any more time shivering in a chilly house.

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