Hansberger Refrigeration Blog: Your AC Repair Resource

Which HVAC Part Will Most Likely Fail This Winter?

HVAC PartIf heating problems should occur this winter, which HVAC part is most likely to be the culprit? Gas-fired furnaces are sturdy, reliable units with a typically long and mostly trouble-free service life. Still, like any mechanical device, malfunctions may occur due to wear and tear on an HVAC part or simply the passage of time.

Aside from routine issues such as a clogged air filter, the HVAC part often associated with heating issues may well be the furnace igniter. All gas furnaces incorporate this component to ignite the flow of gas when the system thermostat signals for heat. Gas-furnace igniters are typically of two types:

  • Pilot light. These components produce a small gas flame that burns continuously to ignite the main furnace burner. Pilot lights are increasingly extinct in new furnaces but are found in older units still installed in homes.
  • Electronic igniters. This is the most current technology installed in new furnaces. Instead of a flame, it uses electricity to ignite the gas. Electronic furnace igniters are either the most common “hot surface” type — a silicon carbide component that glows red hot when energized — or an igniter that generates an electric spark to light the gas flow.

What Can Go Wrong?

  • Pilot light failure most often occurs due to thermocouple issues. This is a vital furnace safety device that continuously senses the pilot flame. In the event the flame goes out, the thermocouple automatically shuts off gas flow. Thermocouple issues may be due to physical deterioration of the component after years of use, including cracking, pinholes, and discoloration of the sensor.  Wiring and/or connections to the thermocouple may also be faulty.
  • Electronic igniters. Depending on regular maintenance, these units typically last from four to seven years before routine replacement is required. Symptoms of a bad igniter include a furnace that will not turn on at all, only blows cold air, or cycles on and off rapidly.  Other symptoms may include a furnace circuit breaker that trips repeatedly.

For qualified professional service to diagnose and repair any failing HVAC part, contact Hansberger Refrigeration and Electric Company.