Can a loose furnace gas valve cause a fire?

Yes, a loose furnace gas valve can cause a fire. Gas is extremely flammable, and for gas appliances, such as a stove or oven or a radiator used to heat a room, the amount of gas used is controlled by a valve. If this valve has been broken, melted, rusted or altered, then more gas can escape, causing a gas leak. A gas leak can be dangerous for people to inhale, especially for children and for people with asthma or other breathing problems. Moreover, if you lit a candle or turned on a gas stove in a room filled with gas, this could be deadly.