Pool Water Is Not Reaching the Set Temperature
If you've set your heater to a specific temperature and the water is consistently falling short — or taking significantly longer to get there — this is one of the earliest and most reliable signs that something is off.
In gas heaters, reduced heating output often points to a partially clogged or scaling heat exchanger, a weakening igniter, or a gas supply issue. In heat pump heaters, it can indicate a refrigerant problem, a dirty evaporator coil, or a failing compressor. In Frisco's hard water conditions, calcium scale buildup is especially common.

