Why does your dad's gas flame and or pilot light go out when the side door gets closed?
I'm assuming you mean the furnace? If the pilot light keeps going out on the furnace, you probably have a rusted through or cracked heat exchanger. Unfortunately the only way to fix the problem is to replace the furnace. IM THE ONE WHO ASKED THE QUESTIONN THIS IS NOT A FURNACE IT IS A GAS HEATER THAT HE PUT IN HIS DINNING ROOM