ChrisL

Hey, so the reason I have been leaning towards the sensor is that the heater is old and does not give any sort of digital temp reading (can only be set to high or low). I set it on high and it stays on for hours when the water is coming from the pool and only like 15 - 20 mins when on the spa. I bypass the pressure sensor, that's why I been ruling out pressure. Thanks for your advice, and adding some heater experts to this thread. Maybe there is some sort of clog on the spa side of the piping.

Thanks for the quick reply. I cleaned my filter really good and the flow seems good. I even bypassed the pressure switch to rule it out. The heater seems to heat up the hot tub for about 10 - 15 mins then will go on and off repeatedly about every 5 mins. But when I ran the heater on my pool for 2 hours it had no problems, I assume because the pool water is 50 degrees and is not getting warm like the spa water and triggering the temperature sensor or some other switch or sensor that is not working correctly and signaling it to stop heating...

Hi, I have an Old Raypak Versa 265b pool/spa heater that I hadn't turned on in over a year. I started it up the other day and it was fine, but heats the spa for about 10 mins then starts turning on and off every 5 mins. If I heat the pool with it, its stays on just fine, which leads me to believe their is an issue with the temperature sensor? Being that the pool is 20,000 gallons, so unless I run it it for 48 hours straight the water is never getting above 70, as compared to the spa which is heating up much quicker. Any advice on if it's most likely the temperature sensor or could it be something else like the Unitherm Governor or high limit switch? Any help and/or suggestions would be greatly appreciated.