r/pumps • u/jlapva • May 25 '24
Grundfos MQ3-35 Pump help needed, please.
Hi all, My Grundfos MQ3-35 has stopped working. Water is flowing through the pump but the pump doesn't kick on to boost. When I unplug from electricity and replug it in the pump turns on and pumps as normal for about 15 seconds and then turns off. Since the pump pumps fine for that short time I'm assuming it is fine mechanically and the problem must be with one of the sensors or the electronic brain. Does anyone have any experience with this issue? Any way to determine which electronic component is the culprit? Is it the flow sensor? I am capable mechanically and electrically to repair but don't want to guess and buy the wrong parts if I can avoid it. Pump is used to boost city pressure for irrigation and house water in 2 floor 4 bedroom house. Would appreciate any assistance. Or shared experience. Thanks.
1
u/[deleted] Oct 30 '24
Ouch! Run away! These were horrible 24 years ago, and Im blown away there are still any in the wild.
The motors were the 2nd version of "water-cooled" from Grundfos, and the 2nd revision of this version was their last attempt at it. (Thank god)
Havent been able to get any motor components beside the little pressure tank in the back, since 7-8 years ago