Pentair Mastertemp 400, 3 years old. Recently started failing. Heater would run for about 10-15 minutes, then stop. Red flashing light, ERR IGN, then would just quit. I could restart it by turning off then on again, and it would go another 5 minutes then fail again. I could nurse it up to full temp by repeating this cycle, but it had become a real problem. We use it every day all year long.
Called a Pentair repair company. Pool tech said main board needed replacement, didn't fix it. I ordered the Pentair kit with all of the sensors, boards, etc. and replaced everything. Still same problem. Finally ran a scope camera down the igniter slot and saw that the heat exchanger was caked with soot. Pulled the top of the chamber and it was so clogged on the inside of the coils that I don't see how it could have worked at all. Used a stiff brush and shop vac to clean the heat exchanger and it's back to working like brand new. Definitely check for soot-caked exchanger coils if you're having this problem.
Called a Pentair repair company. Pool tech said main board needed replacement, didn't fix it. I ordered the Pentair kit with all of the sensors, boards, etc. and replaced everything. Still same problem. Finally ran a scope camera down the igniter slot and saw that the heat exchanger was caked with soot. Pulled the top of the chamber and it was so clogged on the inside of the coils that I don't see how it could have worked at all. Used a stiff brush and shop vac to clean the heat exchanger and it's back to working like brand new. Definitely check for soot-caked exchanger coils if you're having this problem.
