BoilerFaultCodesWhat the manual says
Manufacturer manualNot a fault code. Service mode selected to min, press service button to return to normal.
What causes this fault?
This issue occurs when the service button has been accidentally pressed or held down, which triggers a manual override intended for maintenance testing. Instead of a malfunction, the boiler is simply stuck in a low-power setting used by engineers to check emissions. It stops responding to your thermostat because it is waiting for a command to exit this specific tuning mode.
DIY fix possible
Locate the 'Service' button on the boiler control panel.Press and hold the 'Service' button for a few seconds until the light stops pulsing.The light should return to a steady state or turn off, indicating the boiler is back in normal mode.
Avoid the next call-out bill
A cover plan would handle faults like 2 pulses (No light): no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.