Safety With Combustion

Like any fossil-fueled heating appliance, nothing should ever be taken for granted; you must always be aware of when a fueled appliance can present danger. One extreme example is a car parked in a garage. Virtually every mature car-owning adult on the planet knows you're not supposed to keep a car running in the garage, yet there's always someone who will defy common wisdom and do it anyway. The amount of carbon monoxide emanating from a recently started vehicle is enormous, much more than a warmed vehicle. I once nicely reprimanded a pregnant mother-to-be (I never met her before, although we had a professional reason for the rather brief and awkward meeting) for idling her car in the attached garage; very un-smart.

Back to the world of heating. Although Sealed Combustion Appliances are vastly safer than its old-era cousin, the Atmospheric Combustion Appliance, one huge concern is the fact that snow can cover the fresh air and exhaust flue-gas pipes and create a no-heat situation at best and a deadly carbon monoxide concern at worst.

In a perfect world, the ideal heating system that utilizes a gas fired heating appliance would vent directly to the roof of the building. The venting tables must be followed, it is very important that the sealed combustion pipes not be too long. The boiler or furnace manufacturer is very clear on how many feet the piping can run, and the amount of elbows installed has a direct effect on the total linier feet the appliance is capable of operating properly. If this measurement is exceeded, it may or may not be dangerous, but you can count on some failed ignition attempts (which could indeed result in snow accumulation, therefore presenting a real CO danger).