Customer was saying he had ran out of oil and wasn’t getting any warm air, turned oil furnace on at thermostat and heard furnace kick on, went to furnace primary control wasn’t tripped and flame was proven, let furnace run, checked all supply vents which had a temperature of 115 degrees, cycled thermostat and one time thermostat didn’t register, thermostat has a short in it, replaced with new digital thermostat p, showed customer how to use it, and tested system, everything came on cycled system no issues to report.