Have Empire Model DV-25-2SG propane direct vent furnace. Pilot lights and stays lit when knob turned to ON. However, when raise thermostat temp from Off the main burner appears to light for an instant and then goes out as does the pilot. Help. It's colld up here in the mountains. This unit is only several years old with few hours of use.
I changed the thermocouple but the problem persists.