Why Does My Furnace Keep Tripping the Circuit Breaker?

Your furnace may be tripping the circuit breaker because of one of these reasons:

• Overload due to loose electrical connection

• Overload due to furnace blower overworking

• Short circuit

Let’s explain the above problems in more detail. 

WARNING: Don’t keep resetting the breaker to turn the furnace back on until you fix the underlying problem. Otherwise, you may be putting yourself in danger. 

Overload due to loose electrical connection

Wires at the breaker panel expand and contract with ever-changing indoor temperature conditions, causing the connections to loosen over time. This can cause the circuit to heat up and sometimes trip the breaker.

Solution: Have an electrician find and tighten the loose connection.

Overload due to furnace blower overworking

Does the furnace run for awhile and then trip the breaker? The blower, the part that circulates air throughout your home, may be overworked and is overloading the circuit, causing it to trip.

What do we mean that the furnace blower is “overworking”?

Well, any time that something blocks airflow in your HVAC system, your blower works harder to distribute air. This can draw more amps, enough to cause your circuit breaker to trip.

Common things that can restrict airflow in your HVAC system include:

• Dirty air filter

• Closed or blocked air vents

• Undersized ductwork

• Crushed ducts

• Poorly designed or improperly installed ductwork

Solution: With the above in mind, try:

• Changing the air filter.

• Opening or unblocking air vents (yes, even those in unused rooms).

• Call a furnace contractor to see if your ducts are undersized (or if your furnace is oversized), poorly designed or improperly installed.

Short circuit 

Does your circuit breaker trip instantly when the unit starts? Then there may be a short circuit in the furnace’s equipment. 

A short circuit happens when a bare hot wire touches another bare hot wire or a bare neutral wire. 

When these two types of wires touch, electricity no longer flows through the entire circuit, increasing amperage (strength of electric current). This increase of amperage can heat up the wire. 

To protect you from a fire, the circuit breaker trips, stopping the electricity’s ability to flow into the circuit.

Learn more about circuit troubles (video).

Solution: Have a furnace repair person find the short and repair it.

Still not sure what’s causing your furnace to trip the circuit breaker? Give Pippin Brothers, the Lawton-area’s most trusted heating, air conditioning, and plumbing company, a call. We’ve been serving Oklahoma since 1978. Contact us for more information.