hi got a ferolli falcon 25kw combi power light and heating light on when no demand and does'nt fire up when demand for water phoned ferolli and said was ch /dhw sensors replaced them and did dry test and was same phoned again and said it must be pcb changed that and is no change any help will do

andy win, March 2011

the water pressure switch on this boiler has a nasty tendency to clog up which would stop boiler firing
is LED 5 flashing? [low water pressure]
but pressure gauge reads ok?
if your confident enough its possible to clear blockage on water pressure sensor provided you follow the boiler manual instructions for removal of WPS to the letter
involves draining boiler,electrically isolating, breaking water connections, cleaning defective parts, refitting, repressurizing, testing for leaks, power on, checking boiler works
if any of this frightens you
best get professional help

manwithnoname, May 2011