I recently noticed that my Pentair MasterTemp heater is cycling on & off without reaching the set temperature. Also, when the heater cycles off, the "Service Heater" light goes on. Any idea what the issue might be? I admit that the heater has not been serviced since I bought it new about 4 1/2 years ago.
Thank you so much for your help.
Kit
Thank you so much for your help.
Kit