Almost everybody has a boiler in their home, however not everyone knows how to reduce boiler pressure. A lot of people fail to understand the way in which a boiler works.

Your boiler moderates your central heating system using water, but the pressure has to be correct if the boiler is going to function properly. Keeping the pressure of your boiler at the right level is not only energy efficient but also cost effective. However, at times, the pressure inside the boiler rises above the optimal level and this can cause unwanted issues. Here, we take a look at how your boiler functions and also how to reduce the pressure inside the system to prevent a major problem from occurring.

What Does Boiler Pressure Mean?

In simple terms, boiler pressure is a reference to the balance between the air and the water inside a central heating system. Don’t confuse this with water pressure which relates to running tap water.

If your boiler is going to work as it should, its pressure has to be maintained at the right level. This means it cannot be allowed to get too low or too high. If the boiler pressure is too low, your central heating may not work properly and it may even cut off completely. Conversely, if the boiler pressure is too high, the system can get overloaded and fail.

What Boiler Pressure Is Best?

There’s no single answer to this question, but the majority of boilers perform best between 1 bar and 2 bars of pressure. This is equal to 14 – 30 PSI (pounds per square inch). On the boiler there will be a pressure gauge to show this figure. Usually, the pressure will be marked out of 4 bars maximum.

What Is The Cause Of High Boiler Pressure?

High pressure in your boiler could be down to several causes. However, you need to be aware that boiler pressure naturally rises when your hot water or heating is being used. This causes spikes in your pressure reading, but those spikes are normal so you don’t have to panic. On the other hand, though, if the pressure goes above 2.5 bar, this isn’t normal. If the pressure remains continuously between 2.5 – 4 bar, your boiler probably has an issue.

A common cause of high pressure in a boiler is having too much water inside the system. Usually, this occurs when the boiler pressure has just been adjusted from a low level. Possibly the filling loop or valve that is used for pumping water into the boiler may have been left open by accident. Normally, this can be found at the boiler’s bottom and you can make sure it’s closed tightly. Another cause of high pressure could be a leaky valve or other faulty part.

How Do I Reduce My Boiler Pressure?

Luckily, it’s quite easy to lower the pressure in your boiler. All you need to do is bleed the radiators in your home. This will reduce the overall pressure in the central heating system and, in turn, this lowers the boiler pressure.

You can do this using a radiator key. Before you bleed your radiators, though, ensure the boiler is cold. This will prevent you from being burned by the hot water. Locate your radiator’s release valve, and using the key, turn it slowly, releasing air out of the radiator. Water will start leaking from the radiator, so keep a towel and container nearby as this will keep the floor from getting wet. Once the bleeding process is complete and no more liquid or air is being discharged, the boiler pressure begins to return to normal.

What If Bleeding The Radiators Doesn’t Work?

If bleeding the radiators doesn’t work, there must be another issue. The pressure gauge may be experiencing a problem, or another component inside the boiler may be faulty – for example, the expansion vessel. You will need the services of a qualified Gas Safe engineer to inspect the boiler and carry out repairs.

Never Carry Out Repairs Yourself

Make sure you periodically check your boiler pressure and take action of it remains over 2.5 bar. If you are experiencing an ongoing problem, first check the filling loop or valve to ensure it is properly sealed. If this doesn’t resolve the problem, bleed the radiators. If neither of these work, contact a qualified engineer. You should never carry out repairs or maintenance on your gas boiler yourself. A trained and qualified boiler professional must carry out all work on your boiler. This will ensure your health and safety is preserved and it will also keep you covered under your boiler’s warranty.