[Pics Inside] Unsure what this part does (electrical fireplace switch)

rdiggidy

Purchased a house that has a Lennox gas fireplace. The gas part of the fireplace is working, however the fan/blower won't turn on. I attempted to get an owners manual from Lennox's website, but their website will not load (www.lennoxhearthproducts.com/).

I started trouble shooting and I think I've found the source of the problem. When the fan is plugged directly into an outlet it turns on and runs, however the fan is designed to go into a a junciton box (not sure if that's the proper termonology). Power comes into this junction box from a wall outlet and then is routed to a knob that appears to varry the power output (via a turning knob) to an outlet on the back of this junction box. The outlet on the back of the junction box is where the fan/blower plug is suppose to plug in. I've tested and there is 120v coming into this box, however no voltage leaving out of the outlet on the back.

On top of this box is something I've never seen before (I'll call it "Item A"). Item A appears to be designed to be in contact with some part of the metal from the fireplace. The junction box expands up and down so that Item A can be in contact with the underside of the fireplace. Initially I thought this might be some type of ground, but the hot wire from the wall outlet comes in on one side of Item A and then leaves the other side of Item A into the "control knob box." (For lack of a better word picture, Item A seems to be set up like a fuse, with power coming in on one side and only leaving the otherside if Item A is functioning properly). I'm not sure what purpose Item A serves. If I bypass Item A (run hot directly to the adjustbale knob), I then get power out of the box (where the fan is suppose to plug in). However there must be some good reason for Item A so I don't want to just bypass it.

I have attempted several times to adjust the box to ensure that Item A is in contact with the metal underside of the fireplace.

Below are some pics, hopefully that will help explain. If more pics or a better description is needed let me know.

My questions are:

-What is Item A?
-What does it do?
-Why shouldn't I bypass it?
-Is there a way to test it is functioning (other than what I've done)
-Any idea why it wouldn't be working?

Thanks for any help you can offer!!

Below is the opened "junction box"



Below is the knob on the front of the box



That silver disc is "Item A." The center of "Item A" depresses slightly.



The back of the "junction box" w/ Item A shown on top.

Red Squirrel

I could be wrong but it looks like some kind of heat sensor. The button looks like some kind of reset.

rdiggidy

Red Squirrel you got it!! Very impressive! I reinstalled everything and ran the fireplace till it got hot (to see if "Item A" was a heat sensor). When it got good and hot the fan kicked on. After it's on, the fan speed can be adjusted using the knob.

Would have NEVER EVER figured that one out. Thank you very much for your help!

(Sad part is that it was working all along, I just wasn't smart enought to know it was working ). Couple hours lost....would have been a lot more without your help!

Termite

I don't know how that thing works but I will say that I'm shocked to see what appear to be the white neutrals and the black phase conductors tied together instead of tied to the matching color. That would send up all sorts of red flags if it were mine.

rdiggidy

That is the way it looks in the pictures, but actually it appears to be wired correctly (I am no electrician by any means). Of the wires that come in from the outlet, 2 of them are not stripped back enough to expose the color of the internal shield (blk, grn, wht). The grn was stripped back (so it is visible, but the white looks black.

In any event it's working (and I found out there is a wall switch I just have to flick once the pilot is lit) and I'm very thankful for the help!