Used tub installed 2 weeks ago. 50 amp GFCI trips at weird hours in the early morning when not in a filter cycle and not in use. Set to auto heat. It has tripped 4 times in 12 days.

Will be glad to provide more info on equipment if needed.

Thanks for all input.

you may have a cracked heating element that is bleeding current into the water, or your circulation pump is faulty. You can start your diagnostic by disconnecting and taping up both heater wires for a day and see if the problem continues. If not, then you have a bad element. If so, I would suspect the circulation pump.