master temp 400

Hello. I have a master temp 400 about .w years old. It powers our pool and spa in the summer and only the spa in the winter. This week it started throwing an HLS error as soon as it gets to 100 degrees. At which point it shuts off the gas/heat, seems to reset, try again, heat for 30-60...

Hi there. I was wondering if one could help me with a MasterTemp start up service code. Today, when I was trying to run my pool heater, the heater would run until it reached a temperature of about 86, then it would kick an error code (e05) and then stop heating the pool but continue to run...

I've had my master temp 400 since 2017 and it seems like I'm replacing sensors and part on it annually. Currently its turns on, heats for about a minute, then shuts off for a minute, then starts on again, and repeats this endlessly. Its showing a HLS error, so I replaced the HLS and ACG...

I have a Pentair Mastertemp 400 heater that was installed late 2021 early 2022. It has been turned on maybe a dozen times since it was installed. Went to turn it on today and I get the ERR SFS after about 2 mins of run time (probably less) then it got the point where it wouldn't try to ignite at...