Grundfos Booster pump why continuously running

John Prohaska

• 1378 Answers
• Posted on Jun 14, 2009

SOURCE: when running it makes a loud continuous loud noise

Your bearing are failing. Replacing them and the seal at a local electric motor repair shop will likely cost around $50.

SOURCE: My Grundfos JPS4 1 HP Pressure Booster Pump keeps coming on for a

Definately sounds like a leak in the pipes from the pressure side of the pump onwards, even the smallest leak will cause it to turn on to regain adequate pressure.

SOURCE: Voltage at pump is 120 & air pressure in tank

it sounds like the pressure sensor or switch is bad.

SOURCE: grundfos mq3-45 pressure booster pump

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SOURCE: Grundfos pump switches on & off continuously with

if you have a pump for the whole house you need to check the bladder tank. there is a air valve on the top. Check the pressure with a tire gauge you should have at least 20 PSI this will stop the pump from the on and off thing.

You can compress air yuo can not compress water. thats why the ballder tank. As the pump work to shut off pressure it is compressing air. then when you use a little water the pump does not run until a large about is run then the pump will re fill the system

Best of luck

R J