SOURCE: With the water running the MQ pump runs intermittently
This is a problem with your bladder in the pressure tank or the pressure switch. Ether one will produce this cycling on and off. Good luck.
SOURCE: My Grundfos MQ pump intermittantly continues to run
I have the same problem and have found that the inlet check valve has a broken shaft in the center of device. It is a multi-piece plastic unit and it looks as if it is not quite seating and therefore the internal pressure leaks slowly back into my low pressure suction line. The pump will start and the pressure will build then shut off for about 30 minutes then cycle again. I am going to replace the check valve.
SOURCE: Grundfos pump leaking?
If it is starting and stopping, it most likely does have some type of leak. The check vavlve is normally installed on the suction side of the pump, and sometimes instead of a check vavlve or in addition to, there is a foot valve. A foot valve is just a check valve (usually with a screen) at the end of the line in the bottom of the cistern. If you have much suction lift, and the check valve leaks (or any leak in the suction piping) then the water will drop back into the cistern. This will also cause the discharge side of the pump system to drop in pressure, causing the pump to restart. You mentioned removeing the pressure tank, that tank keeps the pump from short cycling when you have low demand on the system. If the pump is higher than the cistern, and you don't see a check valve between cistern and pump then you most likely have a foot vavle in the cistern. Hopefully it's accessable by removing the pipe.
SOURCE: grundfos mq3-45 pressure booster pump
Thanks for your question!
I'm sorry that you haven't received an answer yet.
The response rate on FixYa FREE questions is usually over 80%, but sometimes questions go un-answered when:
1. the question is unclear, incomplete, or poorly worded...
2. the question is mis-categorized - so the correct experts aren't viewing it...
3. the question requires an answer for something that cannot be explained online adequately...
4. specific training, tools, or equipment are required to avoid injury or death...
5. the Experts that are online simply don't have the resources to answer your question fully...
Please feel free to re-work your question if you feel one of these may be the reason.
Of course you are not required - but converting your question to a PAID one usually increases the reply rate as well.
Normal rates for FixYa are...
$ 9.99 answer for one question.
$12.99 Live Real-Time online chat or premium e-mail support.
$29.99 Live Real Time phone support
Sometimes FixYa will run specials for unlimited questions via monthly subscription or reduced rates for limited periods.
Consider the savings that can be had when an informed Expert can save you a $100 service call, or a $350 trip to the car dealership.
Your problem solved - guaranteed! Or your money back!!
If you don't want to pay - feel free to re-submit your question so it returns back to the top of the work queue if you still need help.
Thanks for using FixYa - a 4 THUMBS rating is appreciated for helping with your FREE question
SOURCE: my mq 35 pump, has started to splutter and the
Sounds like it may be air in the system - there is a black plastic bleeder screw on the top of the pump - open it and let air escape, if any, then fill with water, close screw and start pump.
281 views
Usually answered in minutes!
×