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  • Dec 16, 2007, 09:36 PM
    Connecting furnace to generator directly?

    I have been reading your Q&A on connecting generators to household electric to power a furnace. My question is, can I connect my furnace directly to the generator? My thought was to find a way to disconnect the furnace from the house current, and connect it up to the generator via a heavy extension cord. This of course would only be done in an emergency. We had an ice storm recently and had no heat. I'm leary of these propane or electric space heaters, so we toughed it out without heat. One thought I had was to wire the furnace with a heavy plug and wire the house current to a good quality three prong outlet in the closet where the furnace resides. Then simply unplug the furnace when you need to power it with the generator. But figured that would not meet with the codes. Anybody got an idea on this that might meet with codes?

    Thanks, Jeff
  • Dec 16, 2007, 10:16 PM
    Furnaces often are on a 20 amp breaker. Any cable in regular use would need to be #12 or heavier. I really think furnaces should be hard wired. You might consider having the plug connected to a double throw switch with the other side hardwired to the house.

    Modern furnaces seem to be finicky about grounds. If the normal wiring has a good hot, neutral and ground connected to the furnace, connecting the same wiring to the generator hot, neutral, and ground should work.

    Did you look at

    It is actually fairly cheap and easy to connect a generator into the house. If you have much of a generator, I would seriously look at it.

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