Adjusting fan operation on Quadrafire 7100

very easy fix with a button type thermal switch. I bet you even have it already installed, just bypassed as per your order. Check it out.

Bench is correct. Your QF 7100 already has a thermal snap disc and if wired according to the directions in the install manual, it should work. I have attached a screenshot of the wiring instructions from the manual. If you are comfortable with wiring, turn off the power to the blower. Then take the cover plate from the switch and knob and confirm that they are wired according to the instructions. If your installer deviated from that, then you may need to either contact them or an electrician.

If everything is wired properly, your snap disc should work. You may not know that it is functioning if you are keeping the switch in the on position all the time. Sometime when you have had a good fire going for a while and the heat has really soaked into the box, turn the switch off. With luck, you will discover that the snap disc has kicked in. Once the fire has burned down and the box cooled off enough, the snap disc will turn the blower off.

The snap disc was very unreliable for me at the beginning. After some troubleshooting, I determined that the metal clip holding the disc to the bottom of the fireplace was a little lose. With the heat, it would allow an air gap between the bottom of the fireplace and the disc. I believe that it created enough insulation that the disc would not turn on. I bent the clip so that it would hold the disc very tightly to the bottom of the fireplace. No more problems like that.

One other thing that I found that will that can impact the snap disc performance is the amount of ash in the bottom of the box. Some is good, but I think too much insulates the bottom enough that the snap disc never gets hot enough. Now when I reload, I scrape the floor of the fireplace above the snap disc clear of ash. Now I no longer have that problem.

Once I came to an understanding with the quirks of my 7100 and I make sure to feed it well seasoned wood, it is completely reliable. I consider myself really lucky since I chose and installed the 7100 before I had found this site. Dumb luck I guess.