BoilerFaultCodesYour boiler has switched itself off as a safety precaution because it has either detected a fault or has become too hot.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Non - Volatile Lockout / Reset O/H or in 'standby' mode
What causes this fault?
This fault occurs when the internal safety sensors detect that the water inside the unit has reached a dangerously high temperature or if the system has failed to ignite properly. The most common reason is a lack of water circulation, often caused by a failing pump or a blockage in the pipework that prevents heat from moving away from the boiler. It can also be triggered by a faulty control board incorrectly reading the system's temperature.
This issue often appears when the heating is first turned on in autumn, as pump components can seize up after being inactive during the summer months.
DIY fix possible
Locate the reset button on the control panel.Press and release the reset button to see if the boiler restarts.Check that your heating controls (thermostat) are calling for heat.Ensure your gas supply is active and hasn't been interrupted.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like Indicator 1 (Reset) Lit — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Glow-worm Hideaway 40B 50B 60B FF is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
Affiliate links — we may earn a commission at no extra cost to you.