I have one of those old gas furnaces in my home. The gas furnace actually works really great still today and I really do not have any plans on replacing it any time in the near future. I have had some heating and air conditioning specialists try to sell me on replacing my gas furnace and exchanging it for a brand new, up to date and pretty pricey central heating and air conditioning system. I have always turned them down! I do have central air conditioning in my home along with a whole home air purification system. Those 2 things are the only things I have that are up to date and part of the latest and greatest in heating and air conditioning technology. I even had to have fresh new ductwork put in to get those things installed into my happy home. They can forget it if they think I will ever replace my gas furnace until I truly and really have to. I know that day will come eventually. But I just do not see it happening or coming any time in the near future. The heating and cooling specialists that do the tune up every year on my heating and air conditioning system as well as the gas furnace even said that the gas furnace is in full working order. They are just required to try to upsell me on the heating and air conditioning HVAC equipment because it is part of their hard job every day in the HVAC field. I do feel for them, but I will not cave in to the same old sales pitches I always get from them!