I had an issue with my heater not staying on longer than about 15 seconds and my pool timer was out. I called my home warranty who fixed the timer but said my control board was bad to due to water leakage and they would not cover it. I decided to tackle it myself. I replaced the control board, membrane and broken plastic cover on the top. When I turned it on, the heater came on for a short time, but the gas didn't kick in. Then the service system light came on. I went to the manual it told me to adjust the water pressure switch, which I did. It came on and would shut off, then come back on and shut off. It is also throwing an r13 code and a water temperature of about 128 for a short time when I turn it on. Do you think it is the water pressure switch? Or is it time for me to call a professional?