I have a mastertemp 400 pentair heater. It has been installed about 1 1/2 years. The last time we fired it up, it would start, run, heat for a bit, then cut out the flame, run for a bit, relight, run for a bit, shut down, etc.
From all I've read, it seems I may have a thermal regulator issue.
Furthermore, in reading the manual closely, it seems I should have a check valve between the heater and the chlorine generator, which I don't and which probably contributed to the issue. Do folks recommend a check valve at this location?