DHW Pump sticking

HI Mike,
When the hot water is run the pump goes through the sequence of trying to run as the board starts to run the pump at the lowest voltage. The pump won't run unless you release the bleed screw on the pump. If you don't release the screw the control board steps up the votage until finaly the pump will run but it is then running too fast so the hot water control steps up and down.
I stripped the pump down and found the impeller went tight when pushed in.
The DHW pump is a UPS15-50X18 which is hard to find can you use a standard 15-50-130 or is the flow and current rating too low?
Where is the best place to get the correct pump?



Regards

Hi strata,

Yes sounds as though you need a new pump, and yes a standard Grundos 15/50 will do.

Cheers, Mike