I can't figure out why our heat pump breaker keeps tripping.

Is it the air handler breaker? The compressor unit breaker? Both? Was anything changed in the house (remodeling) that could have contacted the wiring? Did you call your HVAC service company? Could be a compressor, contactor, broken wiring connection, bad breaker... Plenty of possibilities.

Call service if you don't understand troubleshooting it. I am not trying to be insulting, it's just that this could be something beyond a simple 'do this and it will work' fix.

EPM