Arrived on site found thermostat powered down. Removed thermostat and found slightly loose common wire and tightened it up. Proceeding to the attic unit I found a blown fuse. All the symptoms of a short are present so I extensively searched for low voltage short and could not find one. Replaced fuse and unit powered on without issue and continued to run for 20 minutes. Discussed with homeowner that this is an intermittent issue which tells me the issue has to be with a circuit board having ruled out a short. The thermostat or the outdoor control board could be causing this issue, but the outdoor control board appears to be in good condition and working properly at this time. This leads me to believe that the thermostat is causing this issue.
