Understanding Low Boiler Pressure Faults: What Are They and How to Fix them.

Boiler Pressure Gauge

At HeatOn Heating we believe every customer should be able to walk into a happy, warm home, especially in the colder months. One of the most common calls we receive is from homeowners facing issues with low boiler pressure, which can cause the system to stop working efficiently or even shut down completely.

In this blog, we’ll explain what boiler pressure is, help identify it, and discuss what you can do to resolve the issue.

What is Boiler Pressure?

Boiler Pressure refers to the amount of pressure in the system that allows it to circulate hot water through the pipes and radiators. Pressure is measured in Bars, with 1 bar being the pressure at Sea Level.

A typical boiler should run around 1 – 1.5 when it is cold and 1.5-2.5 when it is hot.

When the pressure drops too low or too high, your boiler might not work as efficiently, and in some cases can cause damage or even breakdown. Not Ideal… So what can you look out for?

How to Check Your Boiler Pressure

Locate the Pressure Gauge: Most modern boilers have their pressure gauge on the front of the unit. The Gauge will usually show a needle or digital reading indicating the pressure.

Once you have located the pressure gauge, check where the needle or digital reading is sitting. Is it below 1 bar or above 2.5 bar? If it is, you may be facing issues with pressure.

Low Boiler Pressure

The most common pressure fault is low boiler pressure. When the pressure drops below 1 bar, your boiler will often display an error code, stop heating or make gurgling noises. Low pressure can result for several factors including:

• Leaks in the System: If there is a leak in the system, whether it is in a radiator, pipe or valve, the pressure will drop. Leaks can be subtle, we recommend checking regularly for signs of water pooling around your boiler, radiator, or pipes.

• Corroded Pipework: Over time, the pipes in your heating system can become corroded, leading to small leaks that are hard to detect but result in gradual loss of pressure.

• Bleeding Radiators: If air gets trapped in the radiators, it can cause the pressure to drop. Bleeding the radiators (releasing the trapped air) is a common DIY fix for this problem. For more information on how to bleed your radiators please CLICK HERE.

• Faulty Pressure Relief Valve: The pressure relief valve controls the pressure inside the system. If it is faulty or damaged, it can cause a loss of pressure. If you believe this is the issue now is the time to call in a professional!

  
  

Gas Boiler with front controls.

Repressurising the system

If the system pressure is too low, you may need to add water to the system. Here is how you can do it:

1.      Turn the boiler off and let it cool down.

2.      Locate the filling loop, this is normally underneath the boiler unit. It is a

If you have noticed an issue with low pressure and you have tried to repressurise, have been unable to find any leaks or signs of corrosion, and have bled the radiators, we recommend calling a qualified gas & heating engineer to diagnose and fix the issue. Of course, visit our website to book an appointment, we can help.