Electrical For Fireplace Insert

Mike Finley

In my house I am removing an old fireplace insert with a blower fan, so there is an existing wire ran to the firebox. The new insert will need electrical too, so I thought I was all set. However as I was looking at it today, I notice on the wire it say 18/3. Turning off the 15 amp breaker in the panel shows this wire shares power with 4 other outlets.

There is a crawl space under this whole section of the house... what are the odds there is a transformer that this 18/3 is coming from? Nobody would have hooked up a 18 ga wire directly to a 14/2 circuit right?

The installer for the new insert made no mention of a transformer, only that he needed power inside the fire box.

CGofMP

A do it yourselfer?
Was the place pre-owned?

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krthomp33

When you removed the old insert, were all 3 wires being used?

What is the voltage and amperage draw of the new unit?

RowdyRed94

Just a thought: is the 18 awg wire stranded? Is 18 awg stranded rated for 15A? I couldn't find a chart in a quick search.

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Mike Finley

I have never used the old insert, it was (actually a wood one with a blower, the new one will be gas), but I was pretty sure at one time I had turned on the blower just to see if it did work at all and I thought it did, however in the process of tearing out the old insert I might have been a bit too let's say enthusiatic? When I opened up the unit to disconect the wiring it no longer worked and one of the wires was loose, however I never paid any attention if it was a ground, a hot or a neutral, and since this is 18ga it wasn't stripped like normal wiring and showed no color other than the black outer coating.

I haven't purchased the new unit yet, all I know from the guy who will install it is he said to have an wire run to a box in the firebox for him. I would think if he meant anything other than 14/2 he would have said so?

Mike Finley

One owner before me and the unit was definitely not an original feature from the builder. Hard to know if it was a qualified instalation or not.

Romex-Racer

FYI, hooking up 18 gauge wire to a 15 amp circuit is no big deal, I do it several times a day and have been doing it for 30 years. Nearly all light fixtures connect with 18 guage and so do doorbell transformers, recessed cans, etc.

More often than not it's not the size of the wire that determines allowable ampacity, it's the type of insulation covering the wire.

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Mike Finley

Well, what the hell? What are you some type of electrician or somethin???

Is what you said true regardless of the length of the wire run? This 18 ga wire is coming up through the fireplace from the crawl space below, so I imagine it is at least 5-6 feet long.

Romex-Racer

Mike, you're gonna have to crawl under there and see what's up.

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CE1

Since they are going to install it, you should do what they ask and have them clarify as to what they really want. That way THEY are responsible if something goes wrong. Just keep an eye on the installer.

fridaymean

Usually we use #14 to connect up the fireplaces. They have fans inside to draw in and evacuate air. They usually do not draw too much power. So, as long as the nearest circuit is not overloaded you should be able to go from there. Also, is it a plug-in or direct wire. Some of the units have a receptacle inside that is wired to, some have a direct wire approach. Make sure there is disconecting means available for servicing the unit. If there is no plug....it is a direct wire then you may want to wire it on a switch.

That being said, some models require a wall switch, others have a remote. Just check to see what you need and go from there.

MSSI

99% that there is no transformer.(I have never seen a low voltage blower)...the blower came with 18 gauge rubber cord which is probably plugged in, in the crawl space or hard wired to a junction box.Make sure you didnt unplug it yanking on the wire..My township requires 12/2 for fireplaces..Although most blowers wont draw more than 3Amps...

Safety-Guy

Mike,
You stated you can trace the wire in the crawl space so go ahead and pull in a 14/2 in place of the existing wire, problem solved.
And as a side not, untill I saw your location I thought you may be my attorney in California, I was gonna get mad at him for not asking me to hop a flight to fix his problem.

Mike Finley

Well this is getting very strange. I crawled in the crawl space up to where the fireplace is, no freaken trace of this wire anywhere to be found! Opened the outlets in the room figuring to see that black wire in one of them, nothing. Looked outside the house to see if it is running from the outside, nothing. I don't get it.

Romex-Racer

Pull out the fireplace and demo out the wall and the floor, it's in there somewhere...

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wildwood

Mike, The actual fireplace insert is probably fed with the 14-2 and your 15A breaker from the closest receptacle. Then there is an 18 guage switch leg running from the unit to a 1-gang switch box on the wall. This is actually pretty common around here. I hope this helps to figure things out. Good Luck! ak

Mike Finley

That would make sense but all I found was the 18 ga wire coming out of the front of the brick face of the firewall, about 2 inches over from the firebox opening, it was going into the fire place insert and hooked up to a blower on a round knob for a switch, which I imagine worked like a dimmer to vary the speed. The old fireplace insert was a wood fired box.

I ran a 14/2 to the box for now and will deal with the 18ga wire as soon as I get a chance to work on this somemore.

Mike Finley

Update to this deal -

I got to work on the fireplace a bit today and solved the mystery of the phantom 18 gauge black wire. It did end up going to one of the outlet boxes in the room, only it made it there by being wire nutted to some 14/2 romex. The romex left the outlet box inside the wall, traveled about a foot than was tucked in behind the base board between the floor and the bottom of the drywall. This little improvised wire chase ran about 12 feet to the fireplace, about 1/2 way there the black 18 gauge wire and the 14/2 romex were wire nutted together and tucked in to bed. Pulling this crap all out, it was nice to see two or three spots where nails had penetrated the romex. In the box the ground was terminated by gently coiling it around the rest of the ground wires. Also back about 6 inches out of the box the romex was cut and gashed and copper was showing.

I'm kind of reluctant to just take it all out and throw it away, it's a shame to have to destroy such craftsmanship.

So the next question is before I try to hunt down the installer of the insert for me you all can probably answer this simple question. Would the new 14/2 going into the fire box for the insert need to be in shielded cable? I can't just run regular old 14/2 romex into the fire box can I?

RobertWilber

read the literature with the insert
Follow the MANUFACTURER specs.
Listing requirements must be met to follow NEC
If NM cable is allowable, guard it to prevent nail damage [plates, EMT, wiremold, etc.]
best of British ...

Check Pilot

Please, please as RobertWilber said, read and follow the manufacturers specs. Most of the stuff I've ever seen says that it is always advisable to call a professional to complete any kind of work if it causes you to have problems.

Electrical wiring deals with two issues mostly. Electrical shock/electrocution and fire. That's kind of the essence of why the NEC is in place.

You are already dealing with high temperatures and fire to begin with. Electric shock/electrocution are a smaller part of your equation. Please be careful and have a qualified electrician help you out with this one.