Is a GFI required for a New Heat Pump and Electrical Box attached to the side of the House?
Located in South Carolina.

Also:
While I am at it, due to non-testing or use of GFI units do they go bad from inactivity? They are 15 years old and rarely have anything plugged into them.

You mention an "electrical box" - do you mean an outlet? The heat pump itself isn't required to be on a GFI circuit, but any exterior outlets should be GFI-protected. If the outlet has a built-in GFI with the "push-to-test" button you should test it to make sure the GFI circuitry is still working. The GFI circuitry won't go bad simply due to lack of testing, but if you don't test it then you won't know whether the GFI still works or not. In my experience outdoor GFI outlets last about ten years or so, then need to be replaced, but it really depends on how well it's protected from the elements.

We need a little more info on "electrical box". Heat pump does not require a GFI, it requires a service disconnect at the unit. Now, IF someone ran an extra cable and put an outlet there, then the outlet needs a GFI. At our mountain house, I have a service disconnect for the AC, not a heat pump, and right next to it is a GFI outlet. For about 10 years or so, NEC has required a house main breaker outside, usually in a combo meter box. That way, emergency responders can kill power outside. I have seen the AC breaker in there along with a GFI breaker for some outside outlets.

For about 10 years or so, NEC has required a house main breaker outside, usually in a combo meter box. That way, emergency responders can kill power outside.This is not an NEC requirement. It's probably a local code amendment.

This is a report from my home inspection and I am having trouble with c&paste of the photo and the words of the report. Will work on it, can copy the words but the photo's are not cooperating.

SUMMARY
Electrical
SERVICE BOX, GROUNDING AND PANEL \ Distribution fuses/breakers
5. Condition: GFCI Tested Faulty
*A Ground Fault Circuit Interrupter (GFCI) electrical breaker in the exterior auxiliary electrical panel of the home failed to respond. This condition is a potential hazard for shock/electrocution.
*The Inspector recommends correction by a qualified electrical contractor.
Location: Right Side Exterior Wall-Auxillary Electrical Panel
Task: Further evaluation
Time: Immediate
8.

I got the wording now to get the photo. If I can't I will try to describe it This box is being powered out of the side of the box containing the Meter that is supplying power to the house. The box has a 220 v breaker and another switch that I am not sure what it does. Thought I had the photo but when I hit the submit button, it went to numbers and then it disappeared. Not a puter whizz by any means. Sorry.

Stan, Could be a GA code, all houses in GA for a long time have main breaker shut off outside.

Looks like you have an outside panel and a slot with a GFI breaker. Not uncommon. Appears breaker may be faulty. It has a white test button on it and apparently it did not trip. Easy DIY job, shut off the breaker supplying the panel and go from there. The 240 breaker may be for your heatpump.

Stan, Could be a GA code, all houses in GA for a long time have main breaker shut off outside.I heard that about the southeast and the west. As far as I know California even has their loadcenters outside.