29th June, 2021

Boiler Pressure Too High

What happens when your boiler pressure goes too high, some possible causes and how to fix it.

Boiler Pressure Too High

The pressure gauge on your boiler needs to be just right for it to run efficiently and safely. If you notice that boiler pressure is too high, this can be dangerous and will cause issues within your hot water and central heating system.

This guide is here to explain why your boiler pressure is too high and how this can be resolved, we also have a quick video available below which can help with boiler pressure issues.

What Is Boiler Pressure And Why Is It Important?

'Boiler pressure' refers to the water pressure within the boiler. The balance of water and air, within the machine, determines the boiler's pressure and these needs to be kept at a reasonable level to ensure that the boiler is gas safe, which is extremely important for your safety, and working well.

The boiler's pressure takes place in the pipes and components of the system, and it can be dangerous if there is too much pressure building up within the system.

There are also issues to deal with if the pressure is too low, our guide on what to do if this is the case can be found here.

Whether you need to reduce your boiler pressure or bring it back to a standard, it is a good idea to consult an engineer. In some cases, a boiler replacement might be a better option, than actually dealing with the issues caused by high or low pressure as a new model can be bought for a fixed price rather than the various expenses of getting your boiler fixed.

How to Read Boiler Pressure

The ideal boiler would be able to tell you when the pressure may need adjusting and then call an engineer for you, but unfortunately, that is not the case.

Instead, you have to keep an eye on the boiler pressure gauge to see whether your combi boiler is working as it should.

On most boilers, it is easy to see when the boiler pressure enters a dangerous zone because of the colours and numbers on the gauge.

Your boiler should be running between the 1 bar and the 1.5 bar, which will be in the green section of the boiler pressure gauge.

If the bar is hitting over 2.5 bars, then the pressure from the water in the system is too high, and anything below 1 bar is too low.

Once the boiler pressure is too high or low, your heating system should automatically shut off to keep it safe. A new boiler model like the Worcester BOSCH 8000 will shut off automatically at a high pressure of three or four bars.

Sometimes high pressure is not always an issue in your boiler, as it can just indicate high demand for water from the system. You will see the release valve go down if this is the case once you have stopped running water in the home, such as from washing dishes or running a bath.

However, if your boiler pressure is too high, at around the 3 bar, without additional demand for hot water, then there is an issue.

Common Causes of High Boiler Pressure

If the boiler pressure is consistently too high, then there is likely an issue with your system.

Let us take a look at some of the common causes of high boiler pressure:

Boiler Needs Replacing

You should only use a boiler for 10 years before it needs to be replaced. There will come a time when your boiler can no longer be fixed as the problems will either be too expensive or too difficult to solve.

If this is the case, then you might be better off buying a new boiler rather than trying to get your old system fixed.

It is possible to get financial support when you need to replace your boiler, however, make sure to go through a credit broker that is authorised and regulated by the Financial Conduct Authority in England.

Standard Faults

The expansion vessel, pressure release valve and the filling loop are some of the common causes of too much water or air pressure in your boiler.

You could check these kinds of valves yourself, but usually, boilers need to be assessed by a gas safe engineer to ensure that your home has safe access to heating and hot water.

In most cases, boilers that have a faulty valve of this kind can be easily fixed, and it does not have to cost a lot to do so.

Make sure to call an engineer as soon as you notice problems with your boiler to get the right solution and keep your home safe.

How to Fix High Pressure Boilers

You might find that you can solve the issues with water pressure yourself if they are not too complicated.

If the issue lies in one of the valve controls we have mentioned, you may find it easy to solve yourself. For example, a filling loop may have to be re-pressurised to solve your issues.

There are other causes of boiler pressure too. Having too much water in boilers is one of the problems you may be able to fix on your own.

To reduce boiler pressure caused by too much water, you first need to check that this is the problem. You can do this by switching the boiler off and seeing what the pressure gauge says.

If the pressure is higher than 1.5 bars, then the pressure is too high.

It is easy to pressure release water from a boiler and fix this issue. In most cases, all you will need to do is bleed the radiators in your home using a radiator key to release some of the pressure.

There is a pressure release valve on every radiator that you can easily find. Turning this will help release pressure from the boiler.

You should only open the radiator valves a little bit and let them bleed until the excess water has come out of your boiler, which you can track using the pressure gauge.

For this, you should get towels or other floor coverings to keep surfaces dry when bleeding radiators around the house.

Call for Help

If your boiler is more than 10 years old, then it is time to get a new central heating system installed in your home. This could be cheaper than the cost of fixing your old one, as most boilers come at a fixed price that you can budget for.

While engineers commonly do not work for a fixed price, use their services if you are having issues with heating your home. This could make things easier for you and get the problem sorted faster than you doing it yourself.

Having a broken boiler is never ideal, but with engineers on your side, you can get the heating working again in no time! Give us a call today on 0333 305 6880, or use our online quote engine to receive a fixed price quote for a new boiler.

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