I have a Raypak heater that's around 7 years old.
It wont stay on. The ignitor would ingite the burner and it just shuts off. No error codes.
I jumped the pressure switch, the high limit switch, the flame roll out fuse and I replaced the ignitor with a brand new one. The flame looks nice and blue then it shuts off. What else could it be? Could it be a bad temperature sensor? Bad board? I have good water flow through the heat exchanger.