hot water?

no hot water at all?
no recognition of hot water demand on boiler?
no fault codes?
best guess
DHW flow switch

Q
November 2013

SERVICE MODE:
The appliance enters the SERVICE mode by turning the control
knob to ‘SERVICE’ (full clockwise). The LED displays a flashing
‘C’. In this mode the appliance runs at the minimum CH output.
This mode allows the gas valve offset and CO2 emissions to be
measured. To increase the output to maximum turn the control
knob back on and return to Service within two seconds.

Patrick
November 2013