If your GFCI is tripping, it could be due to a bad heater element, pump, blower or ozonator. To determine which component is causing the problem, unplug the components one at a time and turn the breaker on. If the breaker does not trip after unplugging the pump, ozonator or blow, you've found the problem and you can now replace that component. If you've unplugged all three components and the breaker still trips, it's likely the heater element. Hiring a technician or replacing the heater is the next best course of action.