I have a 20 year old CP-100 Pool/Spa Control System, just recently the pump has not been turning off at the selected time. I have to turn it off at the breaker, the next day it seems to have reset itself and works fine for several days but eventually it happens again. I replaced the time clock a few weeks ago because it was making a loud buzzing sound, this did not resolve the shutoff problem. It sounds like maybe a relay may be sticking or malfunctioning. Any ideas on what may be happening and how to repair?
Thank you