Looking for guidance and advice for an issue I’m having with my Pentair Mastertemp 400 gas heater. We keep the heater at 68 through winter and raise the temp when we want to use it as a “hot pool”. Turned the temp to 80 two days ago to get it closer to our desired temp for Christmas Eve. On Christmas Eve we turned it up to 95. It climbed up to 93 before throwing a service light indicating high limit switch. I read that flow is often the culprit so we cleaned the cartridge filter today to see if that would fix it. Upon cleaning, we turned the temperature again to 95, all seemed well and it climbed from 80 to 91/92 and then shut off again throwing the same error. Any ideas what route I should go from here or which parts I should replace next. With us running it year round in KS winter, I really would like to get it running correctly before our winter really kicks in. Thanks in advance for the help!