Boiler keeps losing pressure?
A boiler that needs repeated pressure adjustment may have a leak or a component fault. Repeatedly topping it up can hide the cause and may not be safe. Record the pressure trend and let a qualified engineer assess the system.
Common clues
- Visible heating-system leak
Damp around a radiator valve, pipe joint, or towel rail can contribute to pressure loss. Do not tighten hot or inaccessible connections.
- Pressure relief or expansion component
A pressure relief valve or expansion vessel issue can cause readings to rise and fall. These components are inside or connected to the boiler and need professional checks.
- Recent radiator work or bleeding
Pressure can change after work on the heating system. A continuing drop after that work should be reported rather than repeatedly corrected.
Useful checks before calling
- 1Record the cold reading
Read the pressure display without removing the casing and note whether the boiler has been running or is cool.
- 2Look for visible damp
From a safe position, check accessible radiator valves and pipework for water. Keep away from hot surfaces and do not touch gas fittings.
- 3Check recent changes
Write down any radiator bleeding, maintenance, or work to the heating system and when the pressure started falling.
- 4Book qualified help
Contact a Gas Safe registered engineer if pressure repeatedly drops or the boiler locks out. Use the exact boiler manual for any user controls.
Never remove the boiler casing or work on gas parts. If you smell gas, leave the property and contact the UK gas emergency service without using electrical switches.
When to contact a repairer
Repeated pressure loss needs a qualified engineer, especially if there is visible water, a discharge pipe dripping, a lockout, or unreliable heat. Do not treat constant refilling as a repair.
Useful details to have ready
- Pressure readings and how quickly they change
- Any visible damp or water from an external discharge pipe
- Recent system work and any error code
Common questions
Is it normal to refill a boiler every few days?
Repeated pressure loss is not something to ignore. It can signal a leak or component issue; contact a Gas Safe registered engineer instead of repeatedly topping up.
Can I look for a leak around radiators?
You can visually check accessible areas from a safe position, but do not touch hot pipes or attempt repairs. Tell the engineer where you see dampness.
Post the repair job for local workers to review.
Share the job details and postcode area to invite offers. You can still post if no matching repairers are listed, but a quote is not guaranteed.