When starting heater, display shows 180, r4 at boot up.
Have set both the pool and spa to 104 degrees max temp, through the control board procedure.
The blower turns on and after factory delay the burner fires up. Operates as it normally would when things where tuned.
During start up, my temp starts in the high 80's, low 90's and fluctuates +- 3 to 4 degrees continuously (pool/spa temp is actually 56 degrees currently)
Once burner starts, temp will start to rise, continually fluctuating, until within a couple of minutes it will shut off once the temp reads 106.
At this point the blower will stay on for the factory specified time if the temp stays at, or above 106. During this time frame, the temp display will continue to rise until is maxes out at 112 and it will fluctuate between 110 and 112 even with the blower shut down and the pool/spa temp in the mid 50's.
I shut down system and breakers for 5 mins., cleaned interior, checked for loose, or dirty connections. Dialed the water pressure switch to be a bit more generous toward a lower pressure (heater is within 5ft. above the pool/spa water level.
System appears to operate as designed and will fire up blower and burner if temp stays below 104, just can't figure out what switch/relay is throwing the erroneous temps?
Any guidance will be greatly appreciated as this polar bear spa thing isn't doing it!!!!