pump running 24/7

[BIG BOY]

hi all, i have a potterton suprima 50 on an open vent system and the pump runs all the time 24/7 any ideas?

 

[croydoncorgi]

You need to check the wiring first. The pump on a system with a Suprima SHOULD be wired TO THE TAGS ON THE BOILER because the boiler uses pump overrun to disperse excess heat as it shuts down. If you have a system with 2 Zone valves, for overrun to work properly there MUST be bypass route - either a pipe with (preferably) an automatic bypass valve connecting Flow before the ZVs directly to Return to the boiler, or a heated towel rail which will ALWAYS have open valves.

If it IS wired correctly, the cause is almost certainly a boiler fault: PCB broken (easy to say for a Suprima - happens all the time!) or a failed temperature sensor.

Since a new PCB is inevitably expensive and also CORGI territory, best advice is to get a qualified engineer to fix it.

 

[just-thinking]

is boiler flow and return pipes cold when pump is running continusly.
has fault just occoured has boiler been working correctly.ie pump stopps after a short time.
has anything altered before fault.

 

[just-thinking]

exchanged hundreds of pcb's on this boiler but not for pump running all the time.other faults and no power to pump have seen.

but suprima should be re named suprise

exchanged several new type of pcb now.and seen loads at stockist to be returned under warranty......

i live in ideal world