We’d like to clear up one of the major misunderstandings about furnaces that we still hear: a gas furnace will be able to supply a home with heat in case of a power outage. On the surface, this makes sense. A gas furnace uses the burning of natural gas to create the heat that then goes through the ventilation system. It’s like an old-fashioned stove this way: no need for electric power, just plain old heat from consuming another power source.
However, this is not true. If your gas furnace doesn’t have electrical power, it won’t run.
The blower fan motor
The main reason that a natural gas furnace won’t provide heat if it doesn’t have electricity is because the blower motor that powers the blower fan requires electrical power. The furnace can produce heat inside the combustion chamber—but that heat won’t go anywhere if the blower fan isn’t running. Because there’s a danger of the furnace overheating without the blower fan, the furnace won’t operate unless the blower has power.
Electronic ignition systems
Even without the need for the blower motor, most modern furnaces require electricity to light their burners. The standing pilot light is no longer the standard for igniting the burners. Electronic ignition systems, either intermittent pilots or hot-surface igniters, handle the job now. This is both safe and more energy efficient. If there’s no electrical power, the furnace won’t be able to start up.
Although this may sound like an inconvenience in the case of a power outage, the electrical components in a gas furnace help to keep the system running safer than older ones. For example, a furnace that’s overburdened will trip a circuit breaker rather than continue to work.
Whenever you run into malfunctions with your gas furnace, look to the contractor who has helped keep Staten Island, NY warm since 1955: Bob Mims Heating & Air Conditioning.