Your complete guide on when and how to repressurise your boiler

The Great British winter is not known for being forgiving. You may find yourself using your boiler significantly more over the winter months, which means you will want it running at peak efficiency. If your boiler is not within the optimal range of pressure (usually between 1 and 1.5 bar), then it may not be working quite as intended.

Many people don’t know this, but you can repressurise your own boiler without the need of an external boiler repair service. Our guide below tells you exactly what you need to know about repressurising your boiler using multiple different methods.

Important: If you follow these steps but your boiler does not repressurise, make sure you utilise our boiler cover with a service or your landlord boiler cover to organise an engineer visit as soon as possible.

When to repressurise your boiler

Your boiler may need repressurising when the internal pressure is not within its optimal range, often considered to be between 1 and 1.5 bar. This may result in your heating or hot water not quite working as intended.

The internal pressure of your boiler is indicated on the front of your boiler by either a digital reading or traditional pressure gauge.

If your boiler has a pressure gauge, you will know that it is not operating at maximum efficiency as the needle will be pointed towards a red section of the display. For digital screens, there will usually be a clear warning displayed or the pressure number will be flashing.

If your boiler pressure is too high, then it is likely that you need to bleed your radiators – if you’re not sure how to do that, we have uploaded a guide to help you.

If your boiler pressure is too low (below 1 bar), you will need to repressurise your boiler to ensure your system is operating at maximum efficiency. There are several ways to do this:

1. Using an internal filling key

Before filling up any boiler with water to help repressurise the system, you must first turn off its power.

Next, you want to detach the tray below the boiler system and take out the filling key. There will be a black plastic manifold at the base of the boiler which the key will fit inside – on this manifold, you will see two logos of a padlock, one open and one closed.

You will want to insert the key so that the arrow is pointing towards the open padlock and turn it to the closed padlock position. From there, you will want to twist the white plastic nut beside the black manifold to release some cold water in the boiler. You will be able to hear this happening.

Keep an eye on your boiler’s pressure display. Once it has reached the required 1.5 bar, tighten the white plastic nut to stop water flow, and twist the key to the locked position.

You can now safely remove the key, though be aware that a little bit of water may also leave the system here – this is perfectly normal.

If your system continues to drip after the removal of the key, ensure the nut is tightened as much as possible.

You can find a detailed video on our FAQ page!

2. Using an external filling hose

When using an external filling hose, first ensure that the boiler is switched off, and that both ends of the hose are securely connected to the corresponding valves. If you do not have your hose to hand, check around your boiler and beneath the kitchen sink.

Next, using a screwdriver, you need to open both valves so that the water can start filling into the boiler. Once you can hear the system filling up, keep your eye on the pressure reader, and isolate the valves once your system has reached the desired 1.5 bar.

Release the end of the hose that feeds into your boiler. At this stage, you can expect some water to drip out of the system, but this will stop after a few moments.

For a more detailed how-to on using an external filling hose, check our FAQ page.

3. Using a Worcester keyless filling link

The newest and most simple method of repressurising a boiler is with a keyless filling link. As always, make sure the power to your boiler is switched off before repressurising.

Remove the tray beneath the boiler and look for a blue lever on one of the pipes. Simply pull that lever down gently and keep a close eye on the pressure display. Once it has reached the desired pressure of 1.5 bar, release the lever.

If you’re not sure what you’re looking for, check out our video on using a keyless filling link on our FAQ page.

Contact us if your boiler hasn’t repressurised

If you’ve followed the steps for your type of boiler but it doesn’t appear to have repressurised, you may need the help of a qualified engineer. Our engineers are specialists in gas, electric, and combi boiler repair, and will get your system back up to full functionality in no time.

Whether our engineers are visiting as part of one of our boiler care service plans or to take a look at a faulty smart heating control system, rest assured knowing you’re getting the best service on the market.

Our boiler service cover plans can give you peace of mind knowing that we are just a phone call away to help get you back up and running. We also have landlord boiler cover options available to ensure your tenants have access to a quick fix if things go wrong.

Thinking of replacing your boiler, joining one of our boiler care plans, or repairing your central heating? Contact us today by emailing or call us on 0333 366 1121.