Hi - I have a Biasi Garda M90F 28S combi boiler which is 14 years old. The boiler has been trouble free apart from the usual maintenance and replacements of diverter valve components, igniters etc but otherwise has been an excellent boiler. I maintain the boiler myself as I am an engineer and originally worked for calor gas. My problem started with the hot water which would run hot but the gauge would reach 170 degrees +, the pressure gauge which is normally 1.2 bar would start to fluctuate from 1.2 to 1.9 and then a 'loud crackling noise' could be heard from I believe the heat exchanger? As a result I have re-kitted the diverter valve, flushed both heat exchangers, replaced both temperature thermistors. I noted that the primary circuit flow switch was faulty as the switch contact was stuck in the 'on position so have replaced this too. The problem I have is the chrome plunger from the diverter valve is not moving out far enough to actuate the flow switch. The plunger moves part way outwards but not sufficient to operate the switch. A new diaphragm was fitted as part of the diverter valve kit. Closing the flow switch manually operates the CH correctly and runs with no problems. I do not know if the plunger was operating correctly prior to disturbing the system. I can still draw hot water with the switch manually closed?
Your assistance would be greatly appreciated.
Your assistance would be greatly appreciated.