Rheostat on Direct Vent Blower

I have an Alaska Channing 3 with a direct vent. I was wondering if anyone has installed a rheostat on their direct vent blower? If so have you seen a savings in coal usage? Also, did you adjust the draft with a bacharach?

I know a guy who has an Alaska stove who has a direct vent and he told me he installed a rheostat on the blower motor that brings in the combustion air. He said that the stove burned much less coal. I would be careful about doing this. I have a direct vent too but am afraid to attempt this. I heard you can burn out the motor if not careful.

I think if I were you I would contact Alaska Co. and go with what they say. You could void all warranties.