I’m being careful about the thermostat

My gas furnace should have been replaced about three years ago. The furnace is right around twenty years old, and hasn’t operated at peak capacity in years.. Every winter, my energy bills are significantly higher, and still every winter my house feels colder. I continually fuss with the thermostat, tweaking it up and up a little at a time, and the furnace runs basically non stop. Over the last several months, the furnace has gotten steadily louder and sometimes makes a truly unsettling grinding sound. I have not had the furnace professionally serviced for two years. The last time my HVAC technician performed maintenance in the furnace, he cautioned me that it was time to replace this equipment. He gave me an estimate in a new furnace, and I was shocked by how much is was going to cost. The technician assured me that a modern furnace would be far more energy efficient and drastically lower my monthly bills. He listed several amazing features like zone regulation, variable speed operation, and wifi accessibility. All of which sound really wonderful of course, but outside my price range. The last thing I want is to secure a loan and end up making payments for a new furnace for the next 10 years. By the time I finally finishing paying for the new furnace, it will be time to replace it once more. I am trying to keep my ancient furnace running so long as humanly possible. I am very cautious about thermostat settings, and make sure to replace the air filter every few weeks. I am also saving my money to prepare for the day my central heating system quits permanently.

heater tune-up