protherm boiler 80b starts up and gets to hot.when fires up again after temp drops cuts out and shows f0 on readout. only way to start up again is to turn boiler off and on again.boiler now only staying on for short time and cutting out.also now showing f3 on display sometimes.

mandy, January 2009

sounds like hot water heat exchanger blocked or partilly blocked had same trouble with mine cleaned out works fine

dave, October 2009