Is it safe to shut down a gas furnace after the heating system in a home I'm living in & what steps should I perform before doing so? It's a gas hot water baseboard heating system set up in the basement with an "Emergency Off" electrical switch connected to it roughly 25 years old, Burnham Boiler Low-Pressure 1983 Boiler # 17092016. We have a gas hot water system right next to the boiler.