If your furnace keeps tripping a circuit breaker when it starts up, the problem might be the transformer. The transformer is a small part that's not too expensive, but it's essential for the operation of your furnace. Here's a look at what the transformer does, signs it might be bad, and repairs that could be needed when it malfunctions.
The Purpose of a Furnace Transformer
The transformer steps down the voltage from the electrical panel to the voltage needed by your furnace to operate the basic controls. The voltage required to do things like control safety features, operate the ignition system, and power electronic circuits are much less than the voltage that comes from the control panel. Reducing the voltage is necessary because too much power could cause damage to your furnace.
Signs the Transformer Might Be Bad
A transformer might malfunction because of bad wiring or loose wiring. This might cause it to be erratic at performing its functions. A transformer might even blow out in a lightning storm or power surge. When the transformer has problems, you might hear a new humming sound. The furnace may not turn on, or it may turn on and then back off quickly. The furnace could also keep tripping the circuit breaker.
Repairs the Transformer Might Need
Fixing a bad transformer is an urgent need. Your home will get cold when your furnace won't run properly, but more importantly, the transformer controls electricity, and when electricity isn't regulated properly, your furnace might be seriously damaged. The furnace repair technician can test the transformer with a voltage meter to check the power coming in and going out of the unit. This pinpoints if the problem is in the transformer or the wiring before or after it. If the transformer is bad, the repair technician might have to replace it, but they'll first look for obvious problems that might be repairable.
For instance, if wiring is loose or bad, the wiring might be the issue, and replacing the wiring might solve the problem. However, a furnace transformer is not expensive, so replacing it is often a good choice. The transformer is held in place with screws and it has wiring on both sides. The furnace repair technician disconnects power to the furnace and then removes the wires and screws holding the old transformer. The old transformer can then be thrown out and a new one installed, and then the wires are connected in the right locations.
As long as running the furnace with a bad transformer didn't cause any other damage, your furnace should be ready to operate normally once the new transformer is in place. When your furnace trips the circuit breaker repeatedly, it's a good idea to call a furnace repair company right away in case the problem is a bad transformer that can be replaced easily.