Diaphram needs replacing.Its a large flatish washer in the valve assembly.They tend to rot.Common problem in combi boilers
Tony Davis, September 2007
Please help - does anyone have the technical helpline number for protherm?
AJ, February 2007
hi just had the same problem with mine and the gas man has repaired the fault ,it was a diaphram that was split .the diaphram controls microswitch for water
j c, January 2007
SNAP mines the same. from what i have read on other forums it looks like its one of three things.
thermistor
diaphram
or most likely the circuit board ( PCB )
