A cold radiator or a radiator with cold spots often indicates that the water is not flowing through the radiator as it should. This is almost always down to an installation issue and is very rarely due to a problem with the radiator itself.
This means that the issue should be easy to correct by following the step-by-step instructions detailed below.
1. Bleed the radiator
Firstly, you need to make sure the radiator has been “bled” properly. Bleeding a radiator means getting rid of any air that has accumulated at the top of radiator, using an air vent/bleed valve. Where air is present, there is no water, which means no heat.
Ideally radiators should be checked for air accumulation at least once a year. Bleed keys (vent keys) can be purchased from a plumbers’ merchant or home improvement store.
Bleeding a radiator is a simple process:
a) Ensure both valves at the bottom of the radiator are open;
b) Attach the bleed key (vent key) onto the bleed valve (air vent) at the top of the radiator;
c) Unscrew the air vent and have a cloth ready to catch minor drips;
d) Listen for the change in sound; you will hear a hissing noise at first (the sound of air escaping), then it will change to a steady squirt of water. At this point you can retighten the air vent.
Please note: On first filling a system it is air that is vented from a radiator. From then on the periodic venting required is actually releasing hydrogen that is the by-product of rusting in the system. If regular bleeding is continually required, then this is a strong indication that the system requires draining, cleaning and refilling incorporating a corrosion inhibitor to prevent further rust in accordance with BS5449 section five commissioning.
2. Check that the valves are open
Make sure the valve is fully open, to ensure water can flow into the radiator.
3. Is a “flow diverter” required?
Certain radiators need “flow diverters” that are fitted internally, to ensure that the water flows in the right direction around the radiator. A flow diverter is designed to ensure that all parts of the radiator get as hot as they should. If a flow diverter is required then it will be sent out with your radiator but occasionally installers do forget to put these in. Failure to install a flow diverter when it is required will almost always result in a radiator not performing properly.
4. Does your system need ‘balancing’?
Finally, if your radiator is still not hot all over, then you need to check whether your radiators need ‘balancing’. Your plumber or heating engineer should balance your system following installation or maintenance of your central heating system. Balancing is adjusting the flow of water through each radiator on a system so that all radiators are running at equal temperatures and take an equal amount of time to reach their operating temperature. Lack of balancing within a system is often the cause of cold spots on radiators, radiators failing to heat up properly, or radiators making noises. If your radiator is not heating up correctly then it is highly unlikely that the problem is caused by a manufacturing fault.
Please note: If you have paid a plumber or heating engineer to install your radiator(s), then unless there is a manufacturing fault with the radiator(s) (which is rare), then any newly installed radiators should function correctly before that person leaves your property. Your installer should also ensure that the performance of any existing radiators on the system has not deteriorated as a result of the work carried out. Problems are sometimes caused by installers failing to balance a system following maintenance but these checks should be included as standard as part of the service provided by them.
For more information on radiators including expertise and technical advice from a specialist, then contact Feature Radiators on 01274 567789, meet the team at their showroom in West Yorkshire or visit http://www.featureradiators.co.uk/