Grundfos CU 301 No contact to pump indicator

[Rod McKnight]

Having an issue with my pump controller. Wife said we had no water so immediately went down to the basement to check things out. I noticed the CU 301 had the LED lit up for the little service man. Cycled the system on and off and the pressure indicator went from 0 to 100 eventually settling to the set pressure of 75. I then dad wife run the faucet and observed the CU 301 kick on and sky rocket to 100 again and kick on the service light then settling down to the set pressure but again setting off the service indicator. Decided to open up the unit to look at the led indicators and the red light was lit for the "No contact to pump". What does this actually mean. Does this mean the controller is not able to control the pump? If so, how does the pump even know when a call for water is made. I also don't like the sky rocket in pressure since this is an older house and I would hate to blow a line. Pump and controller are the same age and are about 9 years old. Any info would be greatly appreciated.

Thanks,

Rod

 

[Valveman]

Wow! You got 9 years before having problems with the CU301. That is impressive. However, now you are screwed. Just remove the CU301 and pressure transducer and replace with a standard 40/60 pressure switch . Just tighten the large adjustment screw until it works at 60/80. That will get you back in water but the pump will cycle on and off until you get a CSV1A installed to deliver the 75 PSI constant you need.

That losing connection thing is very common with the SQE type pump. It has been doing it for a long time and you didn't even know it as they cycles 1000 times before they even say lost connection.

You can see one doing the same 100 PSI thing in the following video and see the link for the VFD pump repair kit here. https://cyclestopvalves.com/pages/vfd-repair-kit

 

[Sponsor]

 

[Rod McKnight]

Thanks for the prompt response Valvman! I woke up this morning and decided to have another go at this thing. Of course, the CU was lit up like a Christmas tree so cycled power and this time nothing. Went immediately to a "no contact with pump" condition. Checked all of the wiring to the pump and everything was good. I forgot to mention in my original post that this pump is in a cistern and a low yield well pump is feeding the cistern. Cistern is full so it's not a water source issue thank God but something else. Decided to make a call since this was now out of my league and I wasn't sure if it was the control unit or maybe even the pump itself. Crew arrived and long story short it ended up being the pump in the cistern. The CU and the pressure sensor was good. Pump looked pretty bad so it was probably time. Question for you Valvman. Will that VFD repair kit work for a cistern pump? With my current setup I do see any sort of pressure switch so not sure this would work for my situation. Your thoughts?

 

[Valveman]

Yes it will. Sounds like you have an SQ pump in the cistern as well? If so then yes the CSV as comes in the PK1A kit will replace the CU301 box on the cistern pump and/or the well pump.

 

[Rod McKnight]

Copy that, thanks again for the info.

 

[Reach4]

I forgot to mention in my original post that this pump is in a cistern and a low yield well pump is feeding the cistern. Cistern is full so it's not a water source issue thank God but something else.

A submersible pump in a cistern should have a flow inducer sleeve. It's cheap. It cools the motor, and I expect the electronics too. I looked for a cut-away picture. This is the best I found: