The water in your boiler needs to be kept at a constant pressure to keep the system functioning as it should.
If you’re having problems with your heating or hot water, then it could be a sign your boiler is losing pressure.
Most modern models use a system called a ‘filling loop’ to maintain pressure, allowing you to easily check whether your system is ok.
Usually, the water pressure gauge should read between 1-1.5 bars of pressure for your boiler to work correctly.
If your water pressure drops below that level, you may begin to experience problems like radiators not heating up or water that isn’t as hot as usual.
What causes a boiler to lose pressure?
There are several reasons why your boiler may lose pressure, including:
- Leaking pipework – If water is escaping from your boiler system, you are likely to experience some loss of pressure. Lots of leaks occur at joints in your pipework or fixtures, so try checking all visible pipework first for signs.
Because much of your boiler’s pipework is located behind walls, it can sometimes be difficult to detect a leak. Evidence to look out for that could indicate a hidden leak includes the sudden appearance of damp patches or mould.
If you do discover a water leak, then invite a professional to repair it.
- Boiler fault – If your boiler has lost pressure then it may simply need to be recalibrated toregulate the amount of water and level of pressure in the system.
This is a job you may be able to do yourself or, if you have an old boiler or don’t feel confident doing the work, then call in a heating engineer to fix.
- Broken boiler component – If there is no water leak and re-pressurising does not resolve the problem, then your boiler could have a broken component.
If that is the case, you will need to call in a qualified heating engineer to diagnose the problem and repair it safely.
Re-pressurising your boiler
If you feel confident, you may be able to re-pressurise a boiler yourself by following instructions in its manual.
Always consult the manufacturer’s guide for step-by-step instructions before attempting to do so.
Usually, re-pressurising a boiler is a relatively straightforward job that can be completed using the following process:
- Wait until your boiler is switched off and cool
- Identify your boiler’s filling loop and check both ends are attached securely
- Make sure you can see your boiler’s pressure gauge and then open both valves on the filling loop, allowing cold water to enter the system.
- Wait until the pressure gauge on your system reaches the correct reading and then close the valves again
- Switch the boiler back on
- Be careful not to over-pressurise your boiler; if you accidently do, you can resolve this by bleeding your radiators