How Do You Bleed A Radiator?

If the thought of bleeding a radiator leaves you feeling a little squeamish, don't worry, it needn't be a messy job. Bleeding a radiator is a simple DIY task that releases air trapped in your heating system. The practice of bleeding your radiators ensures your heating system works at maximum efficiency, warming your rooms effectively, and potentially reducing your energy bills.

Why do you need to bleed your radiators?

There are several reasons why you might need to bleed your radiators. These include:

• The top of your radiator feels cold: This is one of the most common reasons for bleeding a radiator. Trapped air prevents hot water from circulating properly around your radiator, resulting in cold spots. When this happens, you need to bleed your radiator to maintain consistent heat. If your entire radiator feels cold, it may be a sign of a bigger problem with your radiator pipes. If bleeding your radiators doesn't resolve the situation, you may need to seek expert help.
• Your radiators are making a funny noise: If your radiators are rattling, thumping, or gurgling, it's probably because air is trapped in the system. Bleeding your radiators will restore your heating system to its usual quiet efficiency.
• Mould or damp patches: Poorly heated rooms are susceptible to mould and dampness. If you notice new patches of damp or mould, particularly in less frequently used rooms, it may be because your radiators are not operating as efficiently as they should be. Therefore, bleeding your radiators may help prevent further incidents of mould or damp.

How often should you bleed your radiators?

To ensure your radiators heat your room to maximum efficiency, you should regularly check your radiators for problems that may be resolved by bleeding. In addition, it's always a good idea to check your radiators before periods of cold weather to ensure your heating system works efficiently and effectively when it is most needed.

What tools do you need to bleed a radiator?

Bleeding a radiator isn’t a big job and only requires a few tools. Here’s what you’ll need:

• A radiator valve key: A small and inexpensive tool enabling you to open and close the top valve on a radiator easily.
• A small bucket: To catch any drips or escaping water. We are not usually talking torrents of water here. A mug, jug, Tupperware tub or pan will suffice.
• A cloth: To help turn the radiator key if the valve is stiff and clean up any drips or spills.
• Gloves: Safety first - your radiators and any escaping air or water may be very hot. A thin pair of gloves will protect you from getting burned.

How to bleed radiators without a key

• If you don't have a radiator key, you may be able to use a flat-headed screwdriver on more modern radiators with a slotted head bleed valve.

A step-by-step guide to bleeding your radiator

Identify which radiators need bleeding: To do this, turn your heating on and wait for your radiators to heat up. Next, check each radiator for any uneven temperature or cold spots by running your hand across the radiator's surface, and listen out for any unusual gurgling or rattling noises. Finally, note any radiator needing attention and note down the symptoms.

Turn your heating off: Turn your radiators off and wait for them to cool. Important: You cannot bleed your radiators while your heating is turned on. Venting air when the boiler pump is running will result in more air being drawn into the system from elsewhere.

Locate the bleed valve: Your radiator bleed valve is typically located at the top corner of a radiator. It will look like a round hole with a square inside, which your radiator valve key should easily fit.

Open and close the bleed valve: Slowly open the radiator bleed valve by turning your radiator key anti-clockwise. You should hear air escaping from your radiator. When the hissing stops and you see water escaping, close the bleed valve by turning your valve key clockwise. Keep the bucket handy just in case you open the valve too far and water squirts out. Repeat the process for every radiator that needs attention.

Check your boiler pressure: Once you've bled all your radiators, you should check your boiler pressure. If the pressure is below 1 bar, you'll need to re-pressurise your system back to between 1 and 2 bars.

Turn your heating back on: You can then restart the process of checking your radiators for cold spots and strange noises, which should now be resolved.

Look after your radiators, and they'll look after you

A central heating system comprising of high-quality radiators will potentially heat your home for many decades to come. Simple maintenance jobs, like bleeding your radiators, will ensure they continue to work as efficiently as they day you first installed them

Alongside a complete range of radiators, in a variety of styles, finishes and materials, Radiators 4u also stock a wide selection of accessories to guarantee your radiators perform as well as they look. For more information, check out our website, or for more advice regarding radiator maintenance, contact our in-house team of experts here.