How to Repressurise My Boiler?

Maintaining the optimal pressure in your boiler is essential for its efficient operation. If you’ve noticed a drop in pressure, don’t panic! It’s a common issue that can be easily fixed. Follow these simple steps to repressurise your boiler and ensure it continues to function smoothly.


If you struggle for any reason our central heating repair services can come to your rescue.


Understanding Boiler Pressure

Before diving into the depressurisation process, it’s crucial to understand the ideal pressure range for your boiler. Most boilers operate best within a pressure range of 1 to 1.5 bar. Anything below or above this range can lead to performance issues.

Identifying Low Pressure

The first step is to determine if your boiler’s pressure is indeed low. Check the pressure gauge on your boiler – it’s usually located on the front panel. If the needle is below the optimal range or in the red zone, your boiler’s pressure is too low and needs to be addressed.


Before attempting to repressurise your boiler, ensure it’s switched off and completely cooled down. You’ll also need a few tools: a filling loop (which is often supplied with the boiler), a cloth or towel, and a container to catch any excess water.

Locate the Filling Loop

The filling loop is a small, flexible hose that connects the boiler to the mains water supply. It’s typically located underneath the boiler or nearby. Once you’ve located it, make sure the valves at both ends of the filling loop are closed.

Open the Valves

Carefully open both valves on the filling loop. This allows cold water from the mains to enter the boiler system and increase the pressure. Keep a close eye on the pressure gauge as you do this – you want to raise the pressure to around 1 to 1.5 bar.

Close the Valves

Once the pressure reaches the desired level, close the valves on the filling loop tightly. Be sure not to overpressurise the boiler, as this can also cause problems. Check the pressure gauge again to confirm that it’s within the optimal range.

Bleed Radiators (Optional)

If you notice that some radiators in your home are not heating up properly after repressurising the boiler, it may be necessary to bleed them. This involves releasing any trapped air from the radiator valves using a radiator key. Bleeding the radiators will help ensure even heat distribution throughout your home.

Check for Leaks

After repressurising the boiler, it’s a good idea to inspect the system for any leaks. Check around the boiler, pipes, and radiator valves for signs of water leakage. If you notice any leaks, it’s important to address them promptly to prevent further damage.

Restart the Boiler

Once you’ve completed the repressurisation process and checked for leaks, you can switch the boiler back on. Allow it to run for a few minutes to ensure everything is functioning correctly. Monitor the pressure gauge during this time to ensure it remains stable.

The Benefit Of Regular Maintenance

To prevent future pressure drops, it’s essential to perform regular maintenance on your boiler. Check the pressure gauge periodically and repressurise the boiler as needed. Additionally, schedule annual servicing by a qualified engineer to keep your boiler in top condition.


Repressurising your boiler is a simple task that can be done without the need for professional assistance in most cases. By following these steps and understanding the importance of maintaining the correct pressure, you can ensure that your boiler continues to operate efficiently, keeping your home warm and comfortable throughout the year.


Remember, if you’re ever unsure or uncomfortable performing these tasks yourself, don’t hesitate to contact a qualified gas safe registered heating engineer for assistance.

If you require assistance in Holmfirth, Honley & Meltham or the wider areas of Huddersfield, Sheffield and Derbyshire please get in touch today.