Boiler will not ignite
Check the steps below first — if you\'re not confident, get it fixed safely today.
Find a Gas Safe engineer near you →⚠️ If you smell gas at any point, do NOT attempt to reset the boiler. Evacuate the property and call the National Gas Emergency Service on 0800 111 999 immediately.
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Most likely cause & what to check
Before calling an engineer, check the basics: is the gas supply on? Check another gas appliance (gas cooker or fire) to confirm gas is reaching the property.
Check your prepayment gas meter if applicable — ensure it has credit. Emergency credit may be available outside business hours.
Check the boiler pressure — a reading below 0.5 bar or above 3 bar will prevent ignition on most modern boilers. Repressurise to 1–1.5 bar using the filling loop if pressure is low.
Press the reset button (hold 3–5 seconds). If the boiler attempts to ignite and then locks out again, do not keep resetting — repeated lockouts can indicate a dangerous fault.
Note down the fault code on the display and call a Gas Safe registered engineer. Common ignition faults include a failed ignitor, spark electrode, or gas valve.
Do not attempt to open the boiler casing or adjust the gas valve yourself — this is illegal under the Gas Safety (Installation and Use) Regulations 1998.
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