Symptom guide

Boiler losing pressure? Find the safe next step

Understand low-pressure symptoms without opening the appliance or guessing at a repair. We cover England, Scotland and Wales; Northern Ireland is not covered.

Call for boiler help

Answer first

What you need to know

If your system pressure repeatedly falls, there may be a leak or an issue with a system component. Repressurising may restore operation temporarily, but recurring pressure loss needs diagnosis.

Safety verdict

Start with visible, external checks only. If you are uncertain, arrange a qualified engineer rather than guessing.

Safe checks before you call

Check the pressure reading when the system is cool.
Look for visible water around radiators, pipework and accessible valves.
Follow your boiler manual only if you are confident using the external filling loop.

What an engineer checks

Diagnosis is more than the visible symptom.

Check the system for leaks and pressure loss.

Test the expansion vessel and related components.

Explain whether the issue is within the appliance or wider heating system.