Cornucopia72
New Member
I have a grundfos constant pressure system that was installed about 2 years ago. Two months ago I noticed the pump was running constantly even when the main valve was shut. I replaced the check valve and that took care of that problem but now the pump runs full speed and then shuts off every few seconds. The pressure oscillates between 90 and 50. Replacing the pressure sensor would solve the problem? I do not want to spend $175 on a sensor if that isn't the problem. Thanks