When the solar is on the valve is not engaging. I read the thread form 2017 about the micro switch problem and have ordered some from Digi-Key to try. I did notice at the end of the swimming season last year at night time I could hear the valve clicking like it was trying to engage. Could that have been the switch going out? I should have the new switches by Wed or Thur and will replace them. It seams like a very simple process.