A gas furnace is an efficient addition to your home's heating and cooling system. But gas furnaces do require a bit more maintenance diligence than electric due to the presence of potentially harmful gases. Gas furnaces have a couple of built-in safety features to minimize the risk of anything going wrong, but those features can, over time, start to experience mechanical difficulties of their own.
Here are two safety features on a gas furnace, how they can malfunction, and why you need to call a heating repair technician immediately if you suspect a problem.
The gas furnace will have a vent that leads from the top of the unit up to either a chimney or a higher vent that sticks up out of your roof. The vent pipes start down at the burner assembly where the incoming gas is lit and, in the process of burning, changes into carbon monoxide. Vents are vital for taking this dangerous gas out of your home and away from your family.
Carbon monoxide is colorless and doesn't have a smell so you or our family could become sick or die before you even knew there was a leak. If you do have a gas furnace, make sure you put a carbon monoxide monitor alarm close to the unit so that you are warned as soon as a leak starts to occur. If the alarm goes off, vacate your home immediately and call in an emergency HVAC technician.
A fully clogged vent can lead to the carbon monoxide leaking, but a partially plugged vent – or one with undersized pipes – can prevent the system from having a sufficient air supply to keep the pilot light lit properly. A weak pilot light can keep your furnace from running as long as you would like or from running as efficiently. If your system has suddenly started cycling on and off quickly, call in a heating repair person to check on the vents.
The thermocouple is a safety device that can trigger the gas supply valve to close if the pilot light should go out. Incoming gas without a light would simply linger in the system, which isn't good for your home or the system. But the thermocouple also signals the valve when the light becomes lit and it's time for gas to come in, so the thermocouple's role is valuable.
A problem with the thermocouple can cause the gas supply valve to stay completely shut or open too briefly, which can cause the furnace to either not kick on at all or to cycle through too fast. If your unit is behaving oddly, or if you smell gas when the pilot light isn't lit, turn off the gas supply to the unit and call an HVAC technician, like those at C & D Cooling & Heating Co for a thermocouple check.