Has your combi boiler suddenly displayed an error code or simply lost pressure?

When this happens, it can stop your combi boiler from providing you and your family with heating and hot water.

However, don’t panic; the good news is that typically this is a relatively simple fix that you can try at home, without having to call in the experts for costly repairs.

How to regain your boiler’s pressure

We’re going to tell you how to get your boiler working again below by following these step-by-step instructions:

  • First, check your gauge. It will likely be close to zero.
  • Now, locate your filling loop. It should be a silver braided hose between two pipes, and there should be a tap attached to it. (For Worcester boilers, this could also appear as a plastic key stored in the bottom panel underneath your boiler. See video below.
  • Your tap should be in the quarter past nine position, so turn it 90 degrees until it is at around the six o’clock mark. You should be able to hear water going into the boiler.
  • Pay close attention to your boiler’s gauge, as this should be moving up to around 1 – 1.5 bars of pressure. Turn off when it rises to around 1.2 so that you avoid overpressurising your boiler.
  • You should leave your tap at around the same position you found it in, back at quarter past nine. You should not be able to hear any more water entering your boiler.
  • Now, in order to get rid of any error codes that have popped up, simply press the ‘reset’ button on your boiler; this should clear the fault.
  • The reset button is normally located on the front of the boiler, and usually looks like a flame symbol with a line or cross through it, as pictured below:


Inspect your boiler

It may also be wise to carry out an inspection of your boiler, in order to check there are no visible bashes or leaks that could have led to a loss in pressure.

Do the same with your radiator valves, as these can easily be bashed with a vacuum cleaner.

Check the outside wall towards the back of your boiler, where you should be able to see a discharge pipe.

Ensure the pipe is not dripping or leaking any water, as this could require a replacement part from a qualified heating engineer.


If your combi boiler loses pressure, it can be an annoying disruption to your home comfort, especially in winter when you rely on your central heating to keep you and your family warm.

Simply follow the above steps in order to regain the pressure and reset your boiler to rid it of any error codes.

Carry out a quick inspection to make sure there aren’t any obvious factors that may have caused the problem; you may need to call in a professional if your discharge pipe is leaking. Good luck!

Question: Have you ever experienced a sudden pressure loss in your boiler?

What was the cause, and how did you fix it? Let us know in the comments section below.