I was on with tech support with Pentair today troubleshooting a Minimax NT heater that had suddenly stopped working. The Minimax NT was throwing an “-ERR” error code. It could only be one of two things. Either the thermistor was shot, or the main circuit board was bad. I tested the resistance of the thermistor and it was fine and that left only the main circuit board which is an expensive replacement. When you’re faced with an expensive repair on an older heater, you’ll have to make a choice about whether it makes sense to continue to throw money at it, or if it’s better to just remove and replace it. In this case the customer had already spent money on the heater and frustratingly, just last week we had gotten it running after cleaning out the burner tray and heat exchanger, so we knew the thing worked and we just had an electrical problem. If I hadn’t seen the heater running the week before, it would be a much tougher choice as to what to suggest to the customer. In this case, we replaced the board and it’s working fine again.
Pentair support suggested that the average lifespan of a pool heater is between 6 and 12 years which follows what I’ve experienced in the field. If you’re in the Dallas area, give us a shout and we can give you an estimate on repair versus replacement costs.