Symptoms of a Short in My Furnace

Irregular Starts and Stops

• If the furnace is turning off and on in short intervals, a short is possibly the culprit. Loose wiring or malfunctioning circuits cause shorts and either possibility results in the furnace potentially shutting off prematurely and then turning back on again as it receives an uneven amount of electricity. The short may be coming from the thermostat, which controls the furnace's on-and-off cycles.

Excessive Carbon Monoxide

• Place a carbon monoxide detector near your furnace and ensure it has a full battery or power supply at all times. Carbon monoxide is odorless, and a short-circuiting furnace can pump quantities of it into the air. The detector alerts you when this risk occurs; if the detector goes off, turn off the furnace, ventilate the house and get the furnace checked by a professional. A short isn't the only potential reason for carbon monoxide release, but it is a possibility that requires exploration.

Breakers Turning Off

• If entire sections of the house are losing power at the same time, including your furnace, than a short in the furnace is possibly to blame. The breakers prevent a circuit overload that causes a house fire by shutting off, requiring you to turn it back on manually. If breakers are shutting off but the furnace is still running, the furnace is not the cause of the short in the house. However, the furnace should be one of the first things you check if it is on a breaker that shuts off regularly.

Irregular Noises

• Listen to your furnace if you suspect a short. Any unusual clicking or banging noises are indicative of a mechanical problem, and an electrical short could be the cause of that. A short that causes the furnace to turn on and off in short cycles often creates these noises because the furnace is not able to slip into a smooth mode of operation. If you do hear noises, have the furnace checked out to verify that everything is working properly.