BoilerFaultCodesTechnical description
Maximum locking number reached – boiler has reached the maximum reset number (5 times in an hour) – attempt 1 reset each hour thereafter.
What causes this fault?
This fault occurs when the boiler has been manually reset five times within a single hour, causing the system to temporarily lock you out for safety. It usually stems from an underlying ignition or flame issue that keeps causing the boiler to fail, leading the user to keep pressing the reset button. The root cause is typically a worn-out ignition part or a fault with the gas supply that prevents the boiler from staying lit.
DIY fix possible
Wait for 60 minutes without touching the boiler to allow the internal timer to clear.Check that your gas pre-pay meter (if applicable) has credit.Ensure any external gas valves are open and that other gas appliances are working.After the hour has passed, perform one single reset to see if the boiler fires up.