I want to start off by saying this board has been a great reference since my wife and I bought our first house a couple years ago. The house came with a large, 45' x 20' inground pool and spill over spa and we knew very little about pool care prior to taking ownereship. It's been a fair amount of work, but, worth it.
I'm hoping someone can point me in the right direction to troubleshoot our Pentair Minimax 400 Millivolt heater. When i run the heater, it will run for about 5 minutes or so, the heater turns off, the service LED becomes lit, then, goes out, and the heater comes on again. It will keep doing this until the water reaches the correct temperature.
It did this when we first moved in. I called the home warranty company who sent out a Pentair service tech who said the issue was likely due to an undersized gas meter. I had the gas company come out and replace the meter with a larger unit which didn't fix the issue. The Pentair tech came back and replaced the flow valve because it was badly corroded; this fixed problem up until recently.
I checked the flow valve and it looked fine; almost new. I also removed the service panels and made sure everything was cleaned out and all electrical connections were good. Does anyone have any suggestions i could try? I'm comfortable with safely working on this heater and replacing components, I just need to know what to check.