Pump Overrun Won't Stop.

[pole_81]

Hi all, I have a Baxi Solo 3 Boiler in Honeywell Y Plan configuration wired in with a Honeywell wire centre. All worked fine for two years but now, with no recent work, the pump rarely switches off after heating the water or house.

Timer comes on, water tank thermostat demands hot water, pump and boiler start, water heats (on timer for one hour) timer switches off, boiler goes off, but the pump remains running until I switch the bolier power off. This used to "reset" the fault but now as soon as power is applied pump starts again.

Seems like a pump overrun fault and I was intending to change the boiler PCB. Any suggestions before I try that?

 

[corgigazza]

assuming pump is wired into terminal on the pcb, this normally indicates a new pcb. Replaced two pcb's due this fault in 2 years & solved the problem.

 

[kevindgas]

sounds more likely to be pump over run stat (also is a lot cheaper than a pcb) so try that first

 

[geoff@cetltd]

No Kev, it's a very common PCB problem

as you should know