F3 fault - does this sound like bad CU200?
F3 fault on my Grundfos CU200 – outside Globe AZ. The well is 8 years old, 500’ deep, 2 GPM (less now) and set up with Grundfos 3 SQF-3 pump, CU200, IO 101, solar, plus grid power on a manual spring timer (use sometimes at night or cloudy days). No prior problems.
Odd thing: the fault occurred using the timer Saturday (cloudy). But over the days since, turning on the timer no longer results in fault indicators - the box just stays unlit. However, when the solar panels come online it DOES display the fault indicators (such as when I reconnected them after closing up the boxes). However, “000” is displayed briefly and I thought I saw the rising arrows (for pumping), then it switches to fault light/F3. Also, once when I turned on grid power it did the same little dance, but not now – no display. BTW the “3” looks like an upside down “F” – top LED segment missing. I have also turned off and on the IO 101.
Opened the two boxes with my handyman and nothing obviously amiss. Cleaned out a few dead spiders – mostly in the IO 101.
Do the changing display suggest the CU200 going bad? (Shouldn't the F3/fault always be on with a pump problem?) Anyone in the Phoenix/Globe with expertise re: Grundfos SQFlex? How to get a “known good” CU200 without wasting $800 if it’s not the problem? Any advice?
Context: There is also a shared well (7 homes), but it went dry a month ago – local mine has diverted City waste outflow water from our canyon a few months ago. 8 years ago, pumping the rested well on grid power (fixed 2.5 GPM) the CU200 would start up at 320-330 watts. That was constant until last summer when the water was diverted. The last startup was at 360 watts, implying about a 60-foot ground water drop. It may drop further and kill the well, so I am on the fence about expensive repairs. We are about to drill down the shared well, fingers crossed. I have 90 young fruit, nut and olive trees.