I recently upgraded to a new tub. The old one worked without a problem for a year @ 220v with a 50 amp GFCI spa disconnect. The new one uses a Balboa digital controller, with a 25501 (REV:1B) circuit board and the same GFCI. Before I bought the tub I ran it for an hour, and the heater worked fine. After the hookup at home GFCI trips immediately. After reading this forum, I disconnected the heater, and reset the GFCI and all pumps, blower, and light work fine. I replaced the heater element, and all is well, for 6 days and then the same problem.

My limited understanding of the reason the GFCI trips is the integrity of the element is comprised and water getting in is tripping the GFCI. This would seem like something that would happen over time, not in 6 days. I know it could have just been a bad element. I just don’t want overlook anything else that could cause this problem. Any help you can give me will be greatly appreciated

PS both elements measured approx 12 ohms across the terminals which I believe is correct. Each terminal to ground measures 1.28 to 1.45 Miliohms. Is that enough to trip THe GFCI?
Is there a spec. for this measurement?

Thanks Curt

Anytime you move a tub - expect to change the element.

That eleminates the first failure.

Next - You could have had a defective element, or perhaps installed it in a fashion that caused damage to the joint where the element joins the install flange - it does happen. There's no real way to tell.

That would/could eliminate the second failure.

Crap happens unfortunately, I've seen it, done it... sworn it off everytime and just gone back and replaced the stupid element. Just use care.

(and it's meg-ohms not milli-ohms).

Fwiw, the readings you're seeing on the element definitely sound like enough to cause the breaker to trip. Have you tried disconnecting BOTH connections to the spa heater element and powering it back up again?

do you have any tips to successfully install a new heater element

It's not uncommon to improperly install an element and cause this type of thing. When the main nuts are being tightened up it's imperative that the stud the nut is being tighten onto doesn't twist at all.