06APR2022 Jason B Arrived for no heat. Customer stated that the internal fuse keeps tripping, he replaced the thermostat, two fuses and itâ€™s still not working. Inspected stat and system found common wire terminated on B causing internal fuse to trip. Corrected wiring and found gas valve shorted to ground. With Homeowner permission I replaced gas valve with universal gas valve. Cycled system into heating. Checked amps, heat rise and voltage. Cycled system into cooling. System is running properly at this time. Recommend washing condenser coils and getting system on maintenance plan.