Boiler Make and Model: Worcester Bosch Greenstar 42CDi Classic
Fault Code: A blue/red flashing light
If your boiler has a red flashing light on the display, this may mean it needs resetting.
In order to reset the Greenstar CDi, press and hold the reset button as indicated above, for 5 seconds.
If there is a power supply to the boiler then an engineer is needed.