How to Bleed a Radiator

As the temperature drops around this time of year we invariably end up turning on the heating to ward off the cold. But of course, as the thermostat temperature goes up, so do our bills, which is less than ideal with sky-high energy prices. So if you don’t already know, it’s time to learn how to bleed a radiator. You’ll be reaping the benefits in minutes.

Why Bleed a Radiator? 

Bleeding a radiator allows trapped air to be released, allowing the radiator to heat up evenly.. Keeping your radiators well maintained will help save energy because they’ll work more efficiently. 

If yours has become corroded or damaged, it’s a straightforward job to replace it with one the same style and size. Check out our ultimate radiator buying guide for everything you need to know when it comes to choosing and fitting new radiators.

If your radiator feels cooler at the top than at the bottom, it probably needs bleeding to let the air out and allow it to heat more evenly. 

If you find you have to bleed your radiators often, get them checked by a heating engineer as there may be a fault somewhere.

This low-effort, high-impact trick doesn’t take long at all and is well worth doing to cut your energy usage.

Step 1

Before draining, make sure the heating is off. Then lay down a towel to catch any water.

Step 2

Use a radiator key (or in some cases a flat-head screwdriver) and turn it anti-clockwise a little – between a quarter- and a half-turn will do it. Be careful not to unscrew it by more than a full turn. You’ll hear the trapped air hissing as it escapes.

Step 3

When the first trickle of water begins to leak out, gently turn the key back clockwise to close the valve. 

And that’s it! Check out our video to see exactly how it’s done.

Now you know how to bleed a radiator, you can stay toasty and start saving on those bills. Don’t have a radiator key? Simply head over to your local Robert Dyas or have a look at our DIY range to get the job done.