Boiler Low Pressure

Do you have a boiler low pressure problem and it will not start when you turn on the heating? This can be a simple enough issue to fix if you know how to do it.

boiler low pressure
Filling Loop

If you have a valve in your hotpress that looks like the valve in the picture above you can add pressure to your system yourself. You need to turn the valves on the pipes so that they are in line with the silver pipe and this will let water into your heating system.

boiler low pressure
Boiler Low Pressure

Some boiler types are quite happy to work on as little as 0.4 bar of pressure, some need as much as 1.8 bar of pressure. This is dictated by the type of boiler installed and the type of heating system that is in the property. For example, most Glow-worm boilers will error out with an F9 error when the pressure in the system drops to 0.4 bar in the system and the boiler will not fire. Vokera Boilers have Low boiler pressure (error codes A04, AL40 or AL41).Ideal Boilers have an error code of F1 for low pressure. All of these error codes mean the same thing; lack of water and water pressure in your heating system.

no water pressure
No Pressure in Heating System

Why do you have low pressure in your heating?

If you have a boiler that’s losing pressure, it’s very likely that there is a leak and even if you can’t see it, that doesn’t mean it’s not there.

For example, there are tiny components like the pressure safety release valve and automatic air vent. If either of these are faulty they might not be constantly leaking water, but they may still be releasing pressure when they shouldn’t. If they are, that’s going to reduce the pressure on the boiler’s pressure gauge over time.

Also don’t completely discount the fact that the boiler’s pressure gauge could be faulty too. This is rare, and it’s only likely to be the case if the boiler has always shown the F1 fault code and the needle on the pressure gauge doesn’t move up or down even when pressure is added. These issues are normally picked up on during the annual service though.

We are available 24 hours a day, 7 days a week for all of your plumbing emergency needs or general plumbing and heating requirements. Call us on 087 4048238, email us on info@cityplumbers.ie or fill in the contact form here.

Leave a comment