BoilerFaultCodesTechnical description
Boiler is stand-by
What causes this fault?
This is not a fault, but rather a status message indicating the boiler has finished its previous task and is resting. It occurs when the water inside the unit has reached the required temperature and the boiler is now waiting for a signal from your room thermostat or timer to start up again. Essentially, the system is in a 'ready' state and is powered on, but there is currently no demand for heating or hot water.
This code is more visible during the summer or shoulder months when your thermostat is likely turned down and the boiler spends more time idle.
DIY fix possible
Check if your room thermostat is turned up high enough to trigger heatingEnsure your heating programmer or timer is set to an 'On' periodCheck that your thermostatic radiator valves are open