Hello. I've had my Enviro EF3Bi pellet stove for a number of years. Last night I was laying on the floor by the stove with my kids and noticed a tiny hole behind the grate below the glass window. Kind of hard to explain so I've posted pics. It doesn't look corroded, it appears as though it might supposed to be there? It looks like a perfectly formed tiny hole. Is this there on purpose or should I put a little screw or something there? I'm sure it's been there for a long time, only way I noticed is that I was laying on the floor right near it and saw the glow of the fire thru it. You'd never see it while standing. Any help would be appreciated. Thanks.