What To Do If Your Boiler Loses Pressure

January 27, 2022 | Boiler Pressure, Boiler Problems

What To Do If Your Boiler Loses Pressure

Boilers are one of the great inventions of modern times, from heating your home at the flick of a switch to providing your family with hot relaxing showers and warm water to do your dishes with. However, like all pieces of equipment there are parts in the system which can at times cause issues with your boiler, and one of the main things that can go wrong with a boiler is to do with the pressure. 

A central heating system is sealed, meaning that within the pipes that run throughout your home to your radiators and taps there is a balance of water and air which keeps the system adequately pressurised. If this balance changes, your boiler can end up being over-pressurised or under-pressurised. 

Thankfully, it’s usually a quick fix, however at times when an internal part is causing the issue, you may need to call a boiler repair service near you to come and fix the problem. 

What Is Causing My Low Boiler Pressure?

When it comes to low pressure in the boiler system it is usually one of two things causing the issue: a leak in the system or radiators being bled to relieve high pressure. As mentioned above, the cause of low pressure is due to an imbalance between the water and air as there is only a finite amount within the system to stabilise the pressure. 

If you have a leak either in your pipes or the system itself, then that slow dripping of water out of the system will inevitably cause a loss of pressure as there is not enough water to sustain the regular functioning of it. Even a small leak can cause this, as the loss of water builds up over time, and if water is not put into the system to rebalance it, you’ll end up with a noticeable pressure loss. 

Look around the boiler, the exposed pipes and around the radiator valves to see if there are any damp areas which could be a tell-tale sign of a leak. Don’t attempt to open up your boiler to find a leak, only a capable and qualified boiler service engineer should be trusted to do this. 

If you find a leak from a valve, simply twist it back to tighten and stop the flow. If a pipe has burst, you will need a boiler and heating technician to attend and fit a new pipe for you or fix the existing one.

If you have had high pressure in your boiler and as a result you’ve bled the air out of all your radiators, the pressure within the system may have dropped significantly. 

Is Having Low Pressure In My Boiler Dangerous?

Low pressure in your boiler system is usually nothing to worry about, and it simply means that the balance of water and air in your closed system is not quite right. The water that is heated and then pumped around to your radiators and taps cannot be circulated in the way it should be. 

Recognising this, the boiler can sometimes shut itself down to prevent any further issues, and it should give an error code on the display screen for you to be able to diagnose the issue. If you have any concerns about your boiler, it’s sensible to call a Gas Safe registered boiler engineer to assess the problem if you don’t think it can be remedied by yourself.

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How Do I Repressurise My Boiler?

Repressuring your boiler, if there are no faults with the internal parts or leaks in the system, is quite an easy fix. The first step is to clear any clutter in front of your boiler, so you have easy access to it. Recheck the gauge to be sure the pressure is under 1 bar. 

Locate your filling loop which can be found underneath the boiler itself. You may see a lot of pipework underneath there, but your filling loop will be silver in colour and a flexible looped pipe which has two small black taps at either end, or if you have an older boiler it may simply be a twist valve for which you’ll need a flathead screwdriver or a knife. 

That pipe allows water to flow into the system, filling it up again and rebalancing the pressure within it. Turn the small taps or valve to a 45-degree position and you may hear the water rushing through into your system. Keep an eye on the gauge at this point and see it rising from the low pressure zone back into the green area, of between 1 and 2 bar. 

Once it has reached this zone, twist the valves back to prevent any more water flowing in, and your boiler should be fully repressurised. 

Still Having Problems With Low Boiler Pressure?

If you have followed the above steps and your boiler does not repressurise properly, or within a day or two it goes back to showing low pressure, you need expert help from a local boiler repair service. Rowlen Boiler Service are dedicated boiler repair specialists and can fix any issues with your heating system. If you’ve tried everything to repressurise your boiler but it’s still not working, don’t hesitate to reach out and give our friendly team a call and we will be with you as quickly as we are able.

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