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Tips, FAQs and Useful Advice

When do radiators need bleeding and how do I do it?

Radiators can need bleeding when they have trapped air or gas preventing hot water from heating your radiator fully. It is fairly simple to bleed a radiator and you can do this yourself providing you follow simple instructions.

First of all, you should identify which radiators need bleeding. To do this turn your heating on, and wait until the radiators are fully heated. Then, being careful not to burn yourself, check how warm each of the radiators are.

Once you’ve found the cool spots turn your heating off to limit the amount of water that may go on to the floor when you bleed the radiators, and get a radiator key or a flat blade screwdriver. At the top of the radiator there will be a valve at one end. Attach the radiator key to the square bit in the centre or put the end of the screwdriver into the groove. Slowly turn the radiator key or screwdriver anti-clockwise – if gas is escaping you’ll hear a hissing sound. Once there is no more gas, liquid will come out and you should close the valve quickly.

After you have finished bleeding all the radiators that needed it, check the pressure on your system is normal by looking at the gauge on your boiler. If the pressure is normal, turn your heating back on, and test your radiators again to ensure they are all now working properly and providing the heating you need with no cool spots.

If the pressure is too low, ‘top up’ using the lever or tap on your boiler, known as the filling loop, and then test your heating.

If you would rather not bleed the radiators yourself, contact us and we can do this for you.


How do I check the water pressure of my boiler, and what do I do if it is too low?

A water pressure indicator can be found on the front of most boilers, they are either a dial or a digital display. If the water pressure is at the correct level, the indicator will be between one and two bars. If it is below one you will need to refill the boiler pressure.

To do this, you should first locate the cold water feed to your boiler, which will usually be a plastic tube under, or next to, your boiler). Gently turn the small tap on the cold water feed until the boiler pressure indicator returns to between one and two, then close the tap. Check then to see if your boiler is working properly again. If it isn’t, or if you are unsure of any aspect of this process please call us, and we will be able to help you.


What can I do to make sure my heating system is ready for the winter?

The first thing to do is be prepared, and start early. Make sure that you have your boiler and heating system serviced yearly, as this is the safest way to make sure your system is ready for the cold weather, but also test the system yourself at the end of the summer, by turning the heating on and checking all radiators are heating correctly. If any of them aren’t, then bleed them and check for any other obvious signs of problems such as cracked or damaged pipes and call us so that we can rectify the problems before winter arrives.

If you have bled the radiators, and they are still not heating the house properly it may be that a natural build up of dirt and sludge has occurred and you should obtain a powerflush of your whole system to clear this out, and ensure that the system is operating at full efficiency for when you need it. Don’t wait till the last minute as this is likely to leave you with at least a few days of a cold house when you least need it.

During winter itself, a common problem is the boiler shutting down, often because of water freezing in the overflow pipe. If this happens, you can normally solve the problem by pouring warm water over the pipe, although this carries with it the risk of cracking the pipe, and so it is better to be forewarned and eliminating the possibility of pipes freezing by insulating them. This is something we can do for you during an annual service, or at any other time of the year when you need it.

Insulation is also recommended for outside taps and pipes as they may also freeze and lead to bigger problems with your system including cracked pipes, and heating shutting down.