Just want some input on if I've thought of everything. Tub was working fine for the nearly 1 year we've had it. The other day the GFI was tripped. It won't reset however. I turn the GFI back to the on position, and it just kind of stays in the middle position, looking like it's still tripped. I have disconnected each component from my controller, except the heater. I plan to do that tonight. If I do that, and still no luck, should the breaker allow me to turn it back on (and use the test button) if I disconnect power from the tub completely? I'm wondering if there is a problem at the GFI breaker since I can't turn it back on at all. I'd think if there was a ground fault in my tub, I could turn it back on and the GFI would quickly trip again. But, it seems I can't turn the GFI back on at all, even for a second or two. Any thoughts... Thanks.

Sounds like your on the right track, remember that you have to finish turning the GFCI off before you can turn it on again. but otherwise disconnect your heater and if all else fails disconnect power to the spa all together, assuming none of that works then you most likely have a bad GFCI breaker and need to replace it.

Well, last night pulled the power from the tub completely so the GFI had no load. Still, the GFI will not turn back on, so it appears to be a problem with the GFI breaker.

I would lean that direction.

Well, after checking it all out this weekend, it appears the breaker went bad after only 1 year. With the load wires disconnected, as soon as I apply input power to the GFI breaker it trips off. I realize that GFI's are sensative and can sometimes trip (and they should to keep me safe), but I don't want to be spending $100+ for a new breaker every year. Granted we had a lightning storm 2 days before the problem cropped up that took out my neighbors TV, Dish, A/C Controller, and Sprinkler System, but for the future is there anything I can do to help the breaker last longer. I mean if I ever get a nuisance trip, and the breaker resets just fine, is there anything in the spa I should check that may be a problem waiting to happen? I've heard the more times a GFI causes the GFI breaker to trip, the more likely it is for the breaker to die down the road.

That is true, however you do have to wait for the nuisance trip to start before you can determine the problem, assuming a new breaker works fine then there should be no problems. Unfortunately acts of nature cannot be prevented and there is no way to really protect your system from this. But you should count yourself lucky if lightning took out only your GFI breaker, as your neighbor has seen...It can be worse.

The GFI is meant to be a sensetive device and they are often out in a harsh environment.
I see a lot of them on water front docks, thats salt water, and they do fail.
They can completely rust away or look perfect and be shot.