QUOTE (MatzoB @ Nov 11 2008, 01:31 PM) I`ve never had to deal with a furnace before. I`m curious to know what how one would know when the furnace needs to be cleaned? And how often do they need to be cleaned?
cleaning the furnace is not that important because it really does not get dirty if you replace the filter every 3 months or so, What is important though is having that inpspection prior to winter start up, ususally sept or october done EVERY year...checking the heat exchanger for cracks and the safetys of the furnace. if there is a crack in the xchanger, CO will be blown into the space and there could be some serious consequences. furnaces have safetys which shut down the furnace if something is not operating correctly, they need to be checked to make sure that they are working properly or you may have a burnt down house with roasted tenants.
not to say that a safety or xchanger cant go defective half way through the winter, but catching this early in the fall is better then catching it in the middle of january.