How to bleed your radiators

How to bleed your radiators.

Many of us may find our houses are not heating up properly or the radiators may not be giving out a lot of heat. Uneven heat in the radiators could be caused by air in the system, this can be presented by the radiator being cold at the top and hot at the bottom. This can be easily resolved by bleeding the radiators and letting the air out of the system. This is done by opening the valve at the top of a radiator very slightly with a key. However, when you bleed radiators, it will let pressure out of the system and if the pressure on the boiler is too low (below 1 bar) it can cause problems with the boiler working properly. If you are unsure please call our office for help and advice.

Here are a few steps to help you bleed your radiators:

  1. Identify which radiators need bleeding – start by turning on the heating system and let all the radiators heat up. Then check all the radiators and make a note of the ones that aren’t heating up evenly.
  2. Turn off the heating – make sure you turn off the heating and let all the radiators cool down before you bleed them. If you bleed the radiators while the water is still hot you could end up scalding yourself.
  3. Bleeding the radiators – once the radiators are cool you can use a radiator valve key to open the valve slightly and let the air out. Be careful to only turn the key a little bit to let the air out, you should hear a hissing noise. Make sure you have a cloth to catch any water that may drip out the valve.
  4. Retighten the radiator valve – once the valve stops hissing, quickly tighten it back up to stop the radiator from losing too much water. Make sure that the valve is tightly closed so it doesn’t leak.
  5. Turn the heating back on – check the pressure on the boiler before turning the heating back on. The boiler pressure should be between 1 and 2 bars. If the pressure is showing too low, the boiler may have trouble working and the system will need to re-pressurised. If you are unsure of how to top up your boiler pressure, have a look on YouTube as some manufactures have videos on how to it top up. Otherwise you will need a gas engineer to attend to top up the pressure in your boiler.
  6. Check the radiators – once the heating is on you can go round the house and check that the radiators are heating up evenly.

If you are unsure on how to bleed your radiators and how to top up your boiler pressure, you can give our office a call on 01453 763332. One of our engineers can bleed your radiators, check the boiler pressure and top it up if it is needed. This way you won’t be left without any heating if you aren’t able to top up the pressure.

Other reasons for uneven heating in the radiators could be due to sludge build up. You can find out more about this on our Power Flushing page.