Hope someone can shed some light.....
For no reason today, my hot water and heating failed. The boiler
(Potterton Kingfisher) fires up, although the temperature of the flue
gases are much higher than normal, and runs for about a minute before
shutting down - possibly overheating. The pump is ok (have removed and
checked & only 3 months old), and if i push the (2 port Honeywell)
motorised valve round with a screwdriver, the pump starts, although
there is a sound like water cavitation as if it can't circulate at
all. The wiring seems ok, but I am not sure where to go next. I
haven't got a lot of money at the moment, so it would be good if
someone could guide me as to where to go next. A plumber is the
absolute last resort!