I thought that being diligent about replacing air filters and cleaning supply and return vents was enough to keep my furnace operating properly.
I believed that professional maintenance was a waste of time and totally unnecessary.
When my furnace quit and needed to be replaced, I changed my opinion. My furnace was only eight-years-old when it failed completely. It malfunctioned during a February blizzard, when the outside temperature was down to negative twenty. The heating system was running just about non stop and struggling to keep up with demand. Because the house felt chilly, I raised the thermostat setting several times. The lack of regular upkeep allowed a significant amount of dust, dander, insects and other debris to accumulate inside the furnace. This build up blocked essential airflow, restricted moving parts and increased the strain on all components. Eventually, the furnace overheated and shut down. Fiddling with the thermostat, hitting the reset button and changing the air filter did nothing to fix the problem. I had no choice but to hire a licensed HVAC contractor. We couldn’t go without heat and I was worried about the water pipes freezing. Calling in the middle of the night meant paying extra for overtime service. The technician inspected the furnace and found a hairline crack in the heat exchanger. That didn’t sound all that serious. He then informed me that a new heat exchanger costs more than replacing the furnace. Apparently, the heat exchanger is the component that prevents carbon monoxide and other combustion gasses from entering the breathing air. It’s essential to safety. Because I had failed to keep up with maintenance, my warranty would not cover any of the expense.