FMI 36E Holes in sides of firebox?

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Nov 2, 2020
Washington, USA
Hi All,
We recently bought an older house with a FMI 36E wood insert. The rear refractory panel was badly cracked so I'm in the process of replacing it. In the process I took out the side panels and noticed there are two holes in the sides of the firebox that look like they should be covered (IMO). They aren't described in the manual, but I _think_ they are knockouts for an optional gas line. The worrying part is that it appears that air has been flowing into them and that seems bad.

Does anyone know what these (square holes) are for and should they be covered up before I put everything back together?


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