Arrived on site to trouble shoot system. Homeowner stated that his furnace is not turning on and he cycled on his AC and that didn’t kick on either. Thermostat is showing that system is heating but system is unresponsive. Found error code E-111 on furnace board stating that system polarity is reversed. After speaking to homeowner, he had an electrician out the day before. System did stop operating shortly after. Unfortunately there would be a charge to repair wiring, unless homeowner calls his electrician back out to fix. He gave me the ok to repair. Re-wired furnace high voltage. Kicked power back on. System fired right up and started heating, no more error code on board. Cycled AC as well everything is working perfectly now. System is fully operational upon departure.