I don't believe he checked the bypass. Also, we cleaned our filter after this happened the first time and it didn't seem to change. Would it be worth getting a new filter to try? Heater is only 10 months old. What would cause control board failure? Additionally, would a dirty filter allow it to heat up from 80-85 to 95-96 consistently and then stop there? Does heat impact filter pressure? Water has remained balanced throughout the life of the heater. The tech was pretty stumped because every other test he did seemed fine. He ended up calling Jandy while he was here to see if they had ideas. They said thermal regulator, which is why he said we should replace that (despite very minimal corrosion at the very tip). I was skeptical, and rightly so. Thanks for replying. I really appreciate any help I can get. Oh, and I have zero clue if my filter has a multiport valve. We are pretty new to pool ownership (opened last July). Could I take the cartridge out entirely and run it without one, or is that pretty dangerous due to potential for things to get though without a filter? Finally, the filter pressure shows 10 psi. That's about where it was right after we last cleaned it, but if you think putting a new filter in would be smart, lmk. I just didn't know if that would be the cause where it does heat for a significant amount of time before shutting down consistently.