There are many things which can go wrong with your boiler as it is a complex system of pipes and other components which keep your home warm and taps running hot water. One of the most common issues however is to do with the pressure, sometimes it can be too low and at other times it can have problems with pressure that is too high. 

In this article we’ll be looking at how to solve boiler high pressure, what causes it and whether you can fix it on your own or if you will need a boiler repair expert near you to check it out. 

What Is Boiler Pressure?

In layman’s terms, boiler pressure is simply the balance of both air and water within the system. So that hot water can be pumped around your home through the various pipes to your radiators, the pressure of the system as a whole needs to be correct. You may be aware that the system which your boiler operates is a closed one, so any changes you make to either the amount of water or air in it affects the entire functioning. 

For example, if you have air in your radiators that needs to be bled out, when you do so your whole system experiences a drop in pressure that needs to be compensated with a top up of water. In a system with too much pressure the opposite occurs, and you may need to take appropriate steps to rebalance the boiler system. 

What Is The Normal Pressure Of A Boiler?

For the majority of boilers in use in homes, the usual pressure is around 1 or 2 bars, which is displayed on the pressure gauge on the front of all boilers. Looking at the gauge, you should see the needle drifting between these two values, and oftentimes this zone is coloured green. Above this value, the gauge may have a section coloured in red, and if the needle begins to enter this area then it’s a sure sign your boiler pressure is too high. 

Even if your boiler is showing pressure in the red area, it still may be able to work as normal, however if it keeps on shutting off or just won’t work at all you have an issue that needs looked at. You may have caused the issue if you’ve added more water than needed to the system when attempting to fix a low pressure problem, or you may have not closed the valves correctly which means water can continually flow into the system. 

When boiler pressure is too high, there are a number of steps you can take to reduce that pressure and alleviate your system.

Steps To Reduce The Pressure In Your Boiler

Usually high boiler pressure is a quick fix and you can self-diagnose, then take a few simple steps to recalibrate the system. Firstly, you should turn off the boiler at the wall and then check that all of the valves underneath the boiler are closed, in some cases this may be as simple as turning a key. 

Once the system has cooled down, you can reduce the overall pressure in the system by bleeding your radiators. Your radiators will have a small valve at the top which can be turned with a screwdriver or a knife. Have a towel ready and turn it slowly until you hear a hissing noise as the air escapes from the top of the radiator. 

If your boiler pressure was very high, then bleed all of the radiators in your home in the same way. Once you have done this, go back to the boiler and take a look at the gauge displaying the pressure, as it should have now dropped back down to safe levels, of around 1 or 2 bar. In some cases, your pressure might now have dropped below 1 and now be under pressurised. 

All you need to do is turn the filling valve at the bottom and top up your boiler again. You will see the gauge rising as you do this, so as soon as you’re back at over 1 but under 2, you can stop the filling. Make sure you close that valve securely, or your boiler will begin moving to high pressure once again. 

Boiler Pressure Still Showing As Too High?

This do-it-yourself fix should have alleviated the problem, however in some cases where the pressure release valve or other internal mechanism is broken and causing the high pressure, you should always know your limits and reach out to a professional boiler repair service in your area. 

Here at Rowlen Boiler Services, we have a large team of professional Gas Safe registered engineers who can help fix your high pressure boiler issues. Just give us a call and we’ll get out to you as soon as possible for a safe and effective boiler servicing.