I had my furnace for less than four years when it completely failed and needed to be replaced. It cost me a fortune, but the problem was entirely my fault. To purchase and install the furnace, I took out a home improvement loan. I was extremely tight on funds at the time and struggling to keep up with all of my various payments. Although the HVAC contractor strongly recommended I enroll in a professional maintenance agreement, I declined. I figured the heater would be fine without annual service for a few years. It only needs to run for approximately six months out of the year. I didn’t consider that while the furnace sits idle, all sorts of dust and contaminants penetrate the inner workings. The debris gradually settles and builds up on the various components, impacting performance. Moving parts are restricted, airflow is blocked, and the heating system is forced to work harder and run longer to meet demand. I failed to notice that my furnace was running for much longer cycles. I thought nothing about turning up the thermostat when the house felt chilly. Eventually, the furnace overheated and quit. Since it was nearly new, I wasn’t all that worried about the cost of the repair. I assumed it would be a quick, simple and inexpensive fix. Unfortunately, the heat exchanger was cracked. A new heat exchanger costs more than a whole new furnace. Because the heat exchanger is the component that keeps combustion byproducts, such as carbon monoxide, from entering the breathing air, it’s super important. Since I’d failed to keep up with professional maintenance, the manufacturer’s warranty was void.