Don’t Turn Your Heating on Until You’ve Done This Simple Radiator Check, Experts Warn

A simple DIY task could be the key to a cozier home this season. Here's why experts recommend tackling it before the cold weather sets in.

As the warmth of summer fades, many people will soon be turning to their thermostats to keep their homes nice and toasty. However, before you switch your heating on, experts say there is one vital home maintenance task you should do first: bleeding your radiators.

"Over time, air pockets can build up inside radiators, and this prevents the hot water from circulating properly," explains Gareth Kloet, energy expert at Go.Compare. "This not only means your home won't heat up as evenly, but it can also put unnecessary strain on your boiler."

"Bleeding your radiators regularly — and particularly before you switch the heating back on — can help make sure you avoid these issues. It's a good habit to check your radiators at least once a year — and early autumn, just before you start using your heating, is a good time."

If your heating is on but your radiators feel cold at the top or are making gurgling noises, it's a telltale sign that they need bleeding. Left unchecked, the problem can quietly drive up your energy bills, as you end up paying for heat that barely reaches your rooms.

Bleeding restores full circulation and gets radiators running efficiently again, all without the expense of calling in an engineer. Most homeowners can finish the entire job in under an hour.

Here's a step-by-step guide to help you:

1. Check your radiator type: Only hot water radiators need bleeding. Steam radiators don't, as this process won't work on them.
2. Find the radiators that need bleeding: Turn the heating on and let the radiators warm up fully. Check each one for cold spots, especially at the top, and listen for gurgling or rattling. Wear light gloves to avoid burns, and make a note of any radiator that needs attention.
3. Turn the heating off and prepare the area: Switch off the central heating and let the radiators cool completely. Then place old towels or dust sheets beneath each one, as a little water will escape during the process.
4. Bleed the radiator: Find the bleed valve at the top of the radiator, usually at one end, and fit the bleeding key into the square slot until it clicks into place. Holding a cloth in your other hand to catch drips, turn the key counterclockwise no more than half a turn. You'll hear a hiss as the air escapes. Once the hissing stops and water starts to drip, close the valve by turning the key clockwise.
5. Repeat on the remaining radiators: Work through each radiator you marked, starting with the one farthest from the boiler.
6. Check the boiler pressure and restart the heating: If the pressure has dropped below 1.0 bar, top it up using the filling loop, then turn the heating back on.

Kloet added that while bleeding radiators won't cut energy bills overnight, it does help heating systems run more effectively, which could prevent wasted energy and higher costs over time. He described it as a simple job that can make a home warmer while easing the strain on the boiler.

But if you find yourself having to bleed your radiators repeatedly throughout the winter, it could point to a bigger problem, so it's always worth consulting an engineer. In the meantime, find out how often you need to be changing your sheets.