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I recently replaced the "No-Fault" 1.5/6KW heater in my '98 Jetsetter J tub due to a leak that had developed on the U bend end of the old one (about a month ago). Then last week we had a major thunderstorm with multiple nearby lighting strikes, which resulted in the loss of multiple appliances (microwave oven, computer monitor, etc.), at the same time the hot tub started tripping its GFCI (Connected in 120V mode), a bit of diagnoses through disconnecting and reconnecting accessories lead me to the heater as the cause of the GFCI trip (confirmed by reconnecting and disconnecting it twice). I reinstalled the functioning, but dripping heater and it heats and does not trip the GFCI. I also compared the Ohm readings for the old leaking heater and the new/GFCI tripping heater using a Fluke 117 multimeter and get nearly dentical readings line to neutral (9.8 vs 9.9 Ohm), and fairly similar readings line or neutral to ground (about 6-M-Ohm on the one that is tripping GFCI and 3M-Ohm on the one that is dripping ,but not tripping GFCI )Does anyone have a guess why this is happening?