I have been told that my stove fan will push metal and wood shavings whenever I turn it on for several months. In other words we cannot use it. That does not make sense. The dealer air hosed it out and that was their one liner. They installed an AIRMAX vent on my roof near the fan. Is that where the debris is coming from or are they correct that this is expected? What should I do at this point? It would seem that the fan assembly needs to be removed and the debris vaccumed out.