Pumped water supply - pump keeps running

Sam Russell

I have a water pump feeding all domestic water (except mains that supplies kitchen tap and downstairs toilet).

It is a submersible pump that was installed about 10 years ago and has worked without problem until about a month ago.

We noticed it was making a noise (more than normal when running). On investigation it was not shutting off and frothing the water in the tank. Pressing various buttons did not fix it, and switching it off and back on did not fix it. So it was turned off for the night. In the morning, I turned on the taps in the bathroom and waited until the water stopped (which took longer than I expected). Turned off the taps and turned the pump back on and all was well.

It was for a few weeks, then it happened again, with the same result. And again for the third time.

Few ideas:

It appears to be a problem noticed late at night, but this may be because it is not noticed during the day.

When a tap is opened, even for a short time, the pump activates. However, when the pump was off, there was a lot of water coming out of the tap before it stopped. Could the 'on' pressure be set too low? Now this has always been like this.

Could the problem be caused by the 'off' pressure be set too low, and the pump is less strong now compared to when new?

Could it be the electrics/electronics beginning to fail?

Or something else?

The system has always worked flawlessly until recently.

shane b

Could be the pressure switch or something on the control board. Had a similiar issue happen with my grundfos mq3 pump. Pump had a slight delay to kick in and took ages to switch off then.
Any idea of the make and model of the Pump?