I have the Pentair MasterTemp natural gas heater for my in-ground pool (pictured below), I can not find a posting or any information on anyone having this same issue so I thought I would start here. When I turn the heater on and press the pool heater it will start up and heat for a little while, (never consistent on how long it will run, sometime a minuter some time 15 minutes). The heater will then randomly change to 'spa' from 'pool' and stop heating. There are no error codes on the screen, the service lights are not on, it shows the temp. of the water, and I have the set temp higher then the water temp. Any help would greatly appreciated!!