Furnace Electrical Wiring

Old 10-12-06, 07:34 PM
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Furnace Electrical Wiring

We had a new furnace installed this summer (along with some additional significant electrical/plumbing/etc. work that I've had to do).

At the time, the old circuit wasn't long enough to reach the new location of the furnace, so the installer put an electrical cord on it for the time being.

Specifically from a wiring standpoint, what are the requirements ? Can I just wire it directly to the breaker ? I know there is an internal junction box. In our last house, there was a switch on the furnace. Is this mandatory ? Our furnace is in the basement, and the electrical panel is actually on our 1st floor. If I was going to shut-off the furnace, I would just do it at the breaker (dedicated circuit).

Old 10-13-06, 08:04 AM
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> what are the requirements

The furnace needs a dedicated 15 or 20A circuit (as per manufacturer's instructions), with a local disconnect, and protection for the wire from the ceiling to the furnace. This usually means a piece of EMT conduit from a j-box on a ceiling joist down the side of the furnace and into the furnace j-box.

> switch on the furnace. Is this mandatory?

Yes. You should also have a general purpose receptacle within 25' I believe of the furnace for service and repair purposes.
Old 10-13-06, 06:00 PM
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You usually need an acessable disconnect nearby the furnace in the same room, typically with an MC from the furnace to the disconnect, with the disconnect towards the entrance to the room.

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