Why Does My Furnace Keep Tripping

Some Canadians may notice that their gas furnace will occasionally trip the circuit breaker in their system. This isn’t an uncommon occurrence, but it does leave homeowners wondering exactly why it happens. Even though most modern furnaces run by burning fuel, they still need electricity to operate some of the unit’s components. The most important of these components is the blower as its job is to circulate warm air throughout the building, and it needs electricity to do this. Also, most newer furnaces are turned on by an electronic ignition rather than a pilot light.

And speaking of the blower, if it overworks, it’s one of the main reasons a furnace can trip the breaker. The blower needs to work quite a bit harder if there’s something blocking the system’s airflow. A dirty air filter is typically the most common reason the blower has to work harder than usual and draw more amps. It becomes harder for the furnace to blow the air through the system if dirt is clogging the filter. If this happens, the circuit breaker can trip, and it will usually do so after the furnace has been running for awhile. Other issues which can cause the blower to overwork include duct leaks, crushed ducts, undersized ductwork, blocked-off or closed air registers, and home air leaks.

However, when the circuit breaker trips, it’s not always the fault of the furnace since the unit may be on the same breaker as other appliances. If there’s more than one device sharing a breaker it could trip due to the other appliance or the circuit breaker could be malfunctioning. If the furnace is the only appliance on the breaker and it causes it to trip, the first thing you should take a look at is the air filter. If the filter’s dirty it’s highly recommended that you replace it with a new one. Once you’ve replaced the filter you can flip the circuit breaker to see if it stays on. You can also try unblocking or opening all the air vents.

If a new filter doesn’t do the trick there could be a loose electrical connection causing the breaker to trip or a short circuit. Electrical wires at a circuit breaker panel actually expand and contract due to changing indoor temperatures and this process can loosen the connections. If this happens the circuit can heat up and trip the breaker. The best way to solve this problem is to find the loose connection and tighten it or have an electrician do it. If the furnace causes the breaker to trip as soon as it comes on then there could be a short circuit in the unit. A short circuit takes place when two bare hot wires touches each other or when a bare neutral wire comes in contact with a bare hot wire.

When these wires touch it stops the flow of electricity through the circuit as the strength of the current (amperage) increases. The circuit breaker will trip at this time to make sure the heated wires don’t start a fire. If the breaker continues to trip it’s a good idea to contact a professional HVAC company like Lloyd HVAC Services to have the furnace inspected and the problem taken care of. Just flipping the breaker back on can be dangerous and cause more damage. We can be contacted at your convenience regarding any residential and commercial solutions concerning heating, air conditioning, ventilation, and gas piping. We specialize in design, installation, and servicing in the Greater Toronto Area.