Why is My Radiator Cold? A Guide To Heating Your Home

Fri 7th Jun 2013 - 3:07pm DIY Troubleshooting Why is My Radiator Cold? A Guide To Heating Your Home

Benjamin Clarke

If you don’t feel as warm as you used to, but the heating is on at the same temperature, you may be having issues in the radiator department. We aren’t saying that finding out what is wrong is going to be easy, and many people will often immediately ring a plumber, but if you have a few hours of spare time this guide will go somewhere towards finding out what the problem is.

The Top of My Radiator is Cool

Column Radiators can get cold at the topIf the radiator is hot at the bottom and cool at the top it’s a pretty big indication that you have air trapped in the heating system. To fix the problem, use a radiator bleeding key to open the air vent at one end of the top of the radiator.

Ensure you have a rag or a towel to catch the water once it starts to flow.

One turn is usually enough to hear air hissing out and as soon as you see water flowing out close the valve. It is important to remember not to open the valve fully and it is also critical that you undertake this work when the heating system is turned off, as the water in the system can be very hot!

If you need to do this work on a regular basis, it is more than likely that you have air entering the system somewhere. This problem does not only cause cool radiators, it can cause corrosion and there may be a problem in the system that needs the attention of a plumber. One possible cause of this problem is the build-up of sludge. Sludge removal liquid is available; simply add the liquid to the feed and expansion cistern. A couple of days later, you will need to drain and refill the system.

All my Radiators are Cool

This problem can be more than likely attributed to the dreaded sludge. Cool radiators are usually caused by this disgusting stuff. What is this sludge? It is black iron-oxide and it is caused by corrosion on the inside of pipes and radiators, resulting in poor circulation of water. The system needs to be thoroughly cleaned with special chemicals, as previously mentioned.

My Downstairs Radiators are Cool, My Upstairs Radiators Are Hot

If the heating is working downstairs, but upstairs is cool, this often indicates that the feed and expansion cistern is empty. Refill the cistern allowing just enough water to float the ball when the water in the system is cold.

My Upstairs Radiators are Cool, Except When Hot Water Only is Selected on The Programmer

If the system is gravity driven, hot water from the hot water cylinder fails to reach the upstairs radiators when a gravity-check valve switches off the heating. When your heating is turned on, hot water will rise naturally above cooler water. The gravity check valve can be found on the flow pipe to the upstairs radiators. If it is stuck in the open position, the pipe on either side of the valve will be warm. It needs replacing; a good time to call a plumber!

Admit Defeat & Call in The Experts

Sometimes, you just won’t be able to work out what is wrong with your heating system or find a simple solution to the problem yourself. There is only so much the internet will teach you! There are plenty of good plumbers in the heating industry to use, so pick up the phone and explain the problem!

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