Looking for some help or info on my fireplace. It is an older wood burning insert. It has an control knob on the wall near it, and when I turn it on I can hear a humming coming from being the insert. It sounds like a stuck fan, but I cannot for the life of me figure out how to access it, and I can't find any info online about this particular brand other than that they are out of business. Has anyone else ever used one of these or worked on one? Can I just use it as a regular fireplace or is burning in it without having the fan or whatever is not working functional dangerous? I'd love to fix it if possible but I'm at a loss. Thanks in advance.