No Water in house, failed when wife was watering garden, no other use that morning. No loghts on CU301 control box panel, when panel lid lifted on 1 led (24v) was steady green and 2 (10v and 5v) were blinking green. No other led lights on circuitboard. Read manul of cu301 from grundfos and read voltage of transducer at board, 12.4v. Manual states this should be between 2 and 10v. Need to try and determine if control board has gone bad or bad transducer or both? Price of control box is $300 and transducer $200.

I have the same problem. Did you find a solution? Thanks@