Furnaces are great heating systems. They’re versatile, fairly cheap, and have a high heat output. However, they also work with some pretty dangerous materials. Natural gas is obviously highly flammable, which is why it’s used as a fuel source. However, burning natural gas also produces a number of very toxic byproducts like carbon monoxide. Knowledge of these risks has led some homeowners to question whether or not furnaces are safe home heating options. Let us put those doubts to rest now. Yes, furnaces are safe heating systems, mainly because they are equipped with quite a few safety measures designed to prevent any mishaps. Let’s take a look at some of those safety features.
The Limit Switch
Overheating is one of the primary contributors to some biggest furnace problems, like a cracked heat exchanger. In order to mitigate that kind of damage, every furnace is equipped with a limit switch. The limit switch is a small device that measures the temperature inside the furnace’s plenum, or main chamber. When the temperature inside the plenum exceeds the safety limit, the limit switch activates and shuts the system down to protect it.
Most furnaces switched from a standing pilot light to an electric ignition device a long time ago. For those that still use standing pilot lights, however, the thermocouple is an indispensable safety feature. A standing pilot light is a small gas flame that burns 24/7, in case the furnace needs to be lit at any time. The flame is fed by its own gas line, which keeps it lit. However, if the flame ever blows out (which is common) there is a risk that the gas will continue to flow into the house and become a fire hazard. Enter the thermocouple. The thermocouple is a heat sensor that controls the gas valve in the line that feeds the pilot light. When it senses the heat from the pilot light, it generates an electric current that keeps the gas valve open, thus keeping the flame lit. When the pilot light goes out, the current stops flowing and the gas valve closes to prevent gas from leaking into the house.
If you’d like to know more about your furnace’s safety features, call G&S Heating, Cooling & Electrical, Inc. We provide furnace services throughout Carnation, WA.