How to replace your furnace

When you should repair instead

Whether you should repair or replace a dysfunctional furnace depends on which part is causing the problem, how much the repair would cost and how old your furnace is.

Problems with the following parts can almost always be fixed, according to Brian Schutt, owner of Homesense Heating and Cooling in Indianapolis:

  • Hot surface ignitor
  • High/low limit switch
  • Anything involving a thermostat
  • Gas valve
  • Flame sensor
  • Thermocouple
  • Filters

If a part is no longer available because your furnace is too old, repair may be impossible.

Homesense also cautions that smaller problems can sometimes signal larger issues. For example, if the high limit switch, which shuts down your furnace if the temperature exceeds a safe level, is faulty, your system will operate at an excessively high temperature, and other, larger issues can arise quickly.