# Furnace Kill Switch



## beenthere (Oct 11, 2008)

No fuse needed or required at the switch, as long as its connected to the proper sized breaker is in the panel box.


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## chris75 (Aug 25, 2007)

All appliances require a disconnect, a switch is a means of disconnect.


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## pcampbell (Feb 7, 2008)

Not sure, might by code need to have the red face plate???


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## biggles (Jan 1, 2008)

that could be considered a service switch which is typical .you might consider cutting one into that attic box and drop another toggle switch into a hall closet or behind a picture with a red painted plate on it.


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## chris75 (Aug 25, 2007)

biggles said:


> that could be considered a service switch which is typical .you might consider cutting one into that attic box and drop another toggle switch into a hall closet or behind a picture with a red painted plate on it.


 
By building code, only oil fired appliances require a disconnect outside of the room of the appliance.


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## jamiedolan (Sep 2, 2008)

chris75 said:


> All appliances require a disconnect, a switch is a means of disconnect.


Can a breaker serve as a disconnect if it is a dedicated circuit and the furnace is in the same room as the panel that serves it?

Jamie


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## hvaclover (Oct 2, 2008)

jamiedolan said:


> Can a breaker serve as a disconnect if it is a dedicated circuit and the furnace is in the same room as the panel that serves it?
> 
> Jamie



No. Not as sole means of interrupting electrical supply.

Switch is supposed to be readily reachable and in plain site mounted on or adjacent to equipment.

I have a job that has the furnace electrical supply connected to a breaker as you describe. I would not want to have to fumble opening the panel door and then hoping I hit the right breaker in an emergency.

A switch at the equipment takes all the risk out of finding the right disconnect.


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## chris75 (Aug 25, 2007)

hvaclover said:


> No. Not as sole means of interrupting electrical supply.
> 
> Switch is supposed to be readily reachable and in plain site mounted on or adjacent to equipment.
> 
> ...


 
Code reference? Of course a breaker can be used as the disconnect. Check out section 422.31


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## chris75 (Aug 25, 2007)

jamiedolan said:


> Can a breaker serve as a disconnect if it is a dedicated circuit and the furnace is in the same room as the panel that serves it?
> 
> Jamie


Yes a breaker can be used as the disconnect. Check out section 422.31 for all the rules that go with it.


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## hvaclover (Oct 2, 2008)

Conflicts with mechanical law. Easier to find one switch on the equipment and not find out that the furnace breaker was mislabeled while turning off at breaker during emergency..


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## chris75 (Aug 25, 2007)

hvaclover said:


> Conflicts with mechanical law. Easier to find one switch on the equipment and not find out that the furnace breaker was mislabeled while turning of at breaker during emergency..


What mechanical law are you speaking of? And not saying I would go out of my way to not include a service switch, but just speaking code. 


People tend to see something done a certain way for some period of time they tend to believe its actually some kind of law.


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## hvaclover (Oct 2, 2008)

Has been included in ever form of mechanical code ever adapted. It is pretty much a unwritten law but more to the fact is it makes sense.


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## Sophist (Dec 16, 2008)

Great Discussion but I failed to convey that the switch I was talking about has a 20 amp fuse with it in the same box. It is metal, has the switch and a small metal cover next to the switch that covers the fuse. 

Would this be overkill? New house with 12-2 to the furnace and a 20amp breaker at the sub-panel.

Currently have just a regular light switch next to the furnace.


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## hvaclover (Oct 2, 2008)

You are good to go with te existing switch. Can't see why you'd want it fused, though. Breaker should plenty over current protection.

But around here the branch circuits are all protected for 15 amps.


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## chris75 (Aug 25, 2007)

Sophist said:


> Great Discussion but I failed to convey that the switch I was talking about has a 20 amp fuse with it in the same box. It is metal, has the switch and a small metal cover next to the switch that covers the fuse.
> 
> Would this be overkill? New house with 12-2 to the furnace and a 20amp breaker at the sub-panel.
> 
> Currently have just a regular light switch next to the furnace.


Yes it would be overkill.  just install a switch within sight of the unit and call it a day.


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