Grunfos shower pump pulsing continuously

[tiernan]

Hi All,

Was hoping you could help with an issue.

I have a Grunfos pump which feeds the top floor bathroom and has started pulsing continuously every time I turn on the tap or shower upstairs. The only way to get it to stop is by switching off the power to the pump. Once switched on again it stays off until the tap is turned on again, which would leave me to believe I don't have a leak in the system? The issue happened the first time a few months ago but went away, now it happens every time water is used upstairs.

Any suggestions would be much appreciated!

Thanks
T

 

[rpm]

Non return valve has failed and letting water run back to pump ? Can you hear or feel water running back through the pipe?

 

[tiernan]

Many thanks for the quick reply.

Difficult to hear or feel as the pump keeps pulsing. Should I be checking both the hot and cold pipes taking water from the pump? Why would switching on and off the pump resolve the issue (temporarily) if the non return valve was faulty?

Thanks again

 

[rpm]

Many thanks for the quick reply.

Difficult to hear or feel as the pump keeps pulsing. Should I be checking both the hot and cold pipes taking water from the pump? Why would switching on and off the pump resolve the issue (temporarily) if the non return valve was faulty?

Thanks again

Because the power is turned off and afterwards there is no demand for water. Would also check any filter(s) are clear of debris.

 

[tiernan]

When I turn off and on the red valve on the cold water outlet pipe it stops completely, but difficult to hear whether there's water flowing back down. Not sure if that confirms your suspicion? Is the non return valve built into that same valve?

 

[rpm]

Sorry and with respect to you trying to fix it yourself but I think it would be quicker and best to call somebody in this time but no that doesnt have a non-return built in to a isolating valve.

 

[tiernan]

I was thinking that myself! Many thanks anyway for your help. cheers