Practically every home in America has a furnace in the basement. These are either powered by electricity, oil or natural gas. Furnaces powered electrically are attributed to being more efficient and safer. I’m not sure what kind of furnace I have at my current residents, but if I had to guess I’d say my furnaces is powered by natural gas. Every place I have lived has had a cylindrical furnace which I used to mistake for the home’s furnace. I know now that those are actually the hot water heater.
As a safety precaution both electric and natural gas furnaces are equipped with furnace pressure switches. These pressure switches will turn the furnace off if the furnace breaks or malfunctions. Every pressure switch on the furnace is circuited together so only one pressure switch is required to turn the furnace off. In most cases, the furnace must then be physically reset by the owner.
There are a number of different pressure switches used for varies types of furnaces. Furnaces that heat water have a water pressure switch. If the switch fails to turn the furnace off the heating fire may burn a whole in the water tank. Air pressure switches monitor air pressure and movements in the combustion area and circulation fan of the furnace. The heat exchanger inside the furnace could burn out ignite I fire if fresh air is not circulating through the system. The switch will also ensure exhaust fuel gases leave the furnace and exit the house through the chimney flue.
Fuel pressure switches are used in furnaces as well. These are used in gas burners and oil furnaces. The pressure switch will monitor pressure levels and make sure the pump has the ability to prepare oil for combustion. Natural gas furnaces employ two furnace pressure switches. There is both a high-pressure and low-pressure switch. Both switches monitor the gas in the line. If one switch were to fail, a devastated fire could erupt.