Grundfos 5SQ-90 - User Manual

Questions and Answers

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stephaniedownsAug 11, 2025
Why Grundfos 5SQ-90 is not working?
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  Mark MillerAug 11, 2025
  Several issues can prevent your Grundfos Water Pump from running. It could be due to blown fuses, which you should replace, checking the electrical installation and drop cable if they blow again. The GFI circuit breaker might have tripped, so try resetting it. There might be no electricity supply, in which case you should contact your electricity provider. Overload can cause the motor protection to cut off the electricity, so check for any motor or pump blockage. A defective drop cable can also be the cause, requiring repair or replacement of the pump/cable. Finally, overvoltage could be the issue, so check the electricity supply.
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Christopher PatrickAug 19, 2025
What to do if Grundfos 5SQ-90 Water Pump runs but no water comes out?
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  Nicole FryeAug 19, 2025
  If your Grundfos Water Pump is running but not delivering water, consider these possibilities: the discharge valve might be closed, so open it. The water level in the well could be too low, requiring you to increase the pump's installation depth, throttle the pump, or replace it with a smaller capacity model. The check valve might be stuck, necessitating you to pull the pump and clean or replace the valve. Alternatively, the suction strainer could be clogged, requiring you to pull the pump and clean the strainer. In some cases, the pump itself may be defective, so repair or replace it.
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Michael WilliamsNov 25, 2025
How to fix frequent start and stop of Grundfos Water Pump?
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  Mark TorresNov 25, 2025
  Frequent starts and stops of your Grundfos Water Pump can be caused by several factors. The differential of the pressure switch between the start and stop pressures might be too small; increase the differential, ensuring the stop pressure doesn't exceed the pressure tank's operating pressure and the start pressure is high enough for sufficient water supply. Incorrectly installed water level electrodes or level switches in the reservoir could be the issue; adjust the intervals of the electrodes/level switches to ensure suitable time between the cutting-in and cutting-out of the pump. A leaking or half-open check valve can also cause this; pull the pump and clean or replace the check valve. Unstable supply voltage can also cause this issue; check the electricity supply. Lastly, the motor tem...