A lot of homes that still use furnaces for heating do not use the old common gas furnace. You will see that when homes do still use furnaces, instead of heating attached to your central heating and air conditioning system, you will find that they are electric furnaces. Electric furnaces are a much safer option over the old gas furnace. This is simply because electric furnaces give no danger of carbon monoxide poisoning or death. Of course, like any electric device, it could cause a fire if the furnace was to blow up or something like that, but you run that risk with any common electric in your home. So, an electric furnace is safe as having your television or stereo in your home. Or, even safe as having an electric space heater. If you are looking to buy a brand new home, and you see a furnace is in it instead of it all being your simple central heating and air conditioning, check it out to see if it is an electric furnace or a gas furnace. I bet you anything, it will be an electric furnace if you are buying a pretty new home made in the last twenty five years or so. Do not let that word furnace scare you off until you know more! I just learned this myself a few months ago when I bought a new home. They mentioned a furnace and I nearly turned it down, until they explained about the furnace being electric. Another really positive breakthrough in heating and air conditioning technology if you ask me!