Metal sticking out inside back of stove

[Windchill]

Hi
I have a Vermont castings winterwarm small wood insert 2080. I was replacing the refractory assembly and I notice there is a piece of metal sticking out from the back. Does anyone know what this could be for?

 

[DAKSY]

Secondary air Probe. it is installed into refractory for accurate secondary air opening intervals.

 

[webby3650]

It’s the secondary air probe. You will need to pull the insert, remove the probe. Install the new combustion box, drill a hole then reinstall a new probe. Depending on the age, you may need to remove the entire convection jacket to gain access to the probe...Or just drill a slightly oversized hole in the new combustion box and proceed with the install.

 

[Windchill]

When I turned it counter clockwise the door underneath open. Should it stay open? Does it open and close by itself when the stove heats up?

 

[webby3650]

There’s a bi-metallic coil on the back side that responds to the heat. It opens and closes on its own depending on the heat being produced.

 

[Windchill]

Thank you