After losing power in your home during a severe winter storm, you may have found that the furnace did not start up once the electricity came back. If so, it is possible that a power surge either before or after the outage may have triggered one of the furnace's electrical safety mechanisms. Fortunately, there are a couple of simple things that you can try when attempting to get your furnace to restart after a power outage.
1. Check the Breaker and GFI Outlet to See If They Were Tripped
The first thing you can try when attempting to restart your furnace after a power outage is to check the breaker, as well as the ground fault interrupter (GFI) outlet if one is present. If there was a power surge when the outage occurred or when the electricity came back on, one or both of these may have been tripped to protect the furnace.
When checking for the breaker, if it is not labeled as the one for the heater, it will be one of the double breakers that deliver 220/240 volts. If the breaker is in the opposite direction as the others, switch it to see if the furnace comes on.
If not, look at the electrical outlet where the furnace is plugged in. If your home or furnace is newer, it will have a GFI outlet that has its own built-in breaker. Push in the button to see if this allows the furnace to power on.
2. Make Sure the Furnace's Safety Switch Is Unengaged
If the unit still refuses to come on, its safety switch may be engaged. If a power surge was able to reach the furnace, the switch may have come on to provide an extra layer of protection.
Push or flip the safety switch, which is usually located on the outside of the furnace's housing. If the heating unit does not come one, however, do not continue to hit the switch, since hitting it too many times will engage the mechanism and make it harder to disengage it.
After resetting the circuit breaker and GFI outlet and making sure the safety switch is off, the sudden power outage may have affected the motor or blower fan, both of which require the attention of a professional. Contact an HVAC contractor who offers heating services to have them look at your furnace so that they can find and fix the problem.