Question: Thanks for your update message. We have a Vermont Castings unvented stove--do you have a recommendation for the best Carbon Monoxide Detector; and should a yearly preventative maintenance be done on it, to assure it is burning correctly? I am still not comfortable with having the unvented appliance in our house--yet last year it worked fine; we live in a 250 year old house in upstate NY- and used it to take the chill out of the kitchen- from 3-6 hours a day; so far have seen no evidence of moisture problems on the walls or windows---Is there anything else we should look for? Sometimes it smells funny when burning, I believe the Instruction manual said something to the effect that it will "pick-up" other fumes in the house; e.g., if I've just cleaned the floors with oil soap, it will smell funny for a while. Answer: The unit should be cleaned at least once a year. The main concern is brushing off any visible soot from the burner tube and getting rid of any dust, cobwebs, etc that might interfere with any air flow around the burner. Also, check the logs to make sure they are seated correctly. Improper log placement can make any unvented appliance burn dirty. I don't have a recommendation for the best CO detector, however I think Consumers Reports has tested them in the past. Check around for this article. Yes, unvented appliances will pick up ambient smells, and change them once they are run through the high temperatures of the burner. The worse, in my experience, are paints, stains, new carpet, nail polish, hairspray and the like. If there is no evident excess moisture, and if you do not have any soot or film on the walls or windows, then it's probably burning well.