For starters, water pressure and flow are crucial. We suggest servicing your filter every time you plan to use your heater for a long time.
Water chemistry can ruin any heater if the PH is not kept between (7.2 – 7.5).
The insides of the heater should be kept as clean as possible… Spiders love dirty places.
It is never good to let anyone else take care of your pool when you are out of town.