Hansberger Refrigeration Blog: Your AC Repair Resource

Troubleshooting Tips for High-Efficiency Gas Furnaces

High-efficiency gas furnaces offer superior performance, as well as reduced energy consumption and operating costs. Additional technology incorporated into these system can recover heat energy typically lost in the form of hot combustion gases exhausted up the vent. High-efficiency gas furnaces divert these gases into a condensing cycle and utilize a secondary heat exchanger to capture heat released during condensation. AFUE (annual fuel utilization efficiency) ratings of these units range above 90 percent.

Because of the complexity of high-efficiency furnaces, effective troubleshooting can encounter numerous issues nTroubleshooting Tips for High-Efficiency Gas Furnacesot presented by standard furnaces, which require the skills and expertise of a qualified HVAC technician.

  • Since high-efficiency furnaces condense gas, a condensate drain system is used to convey water to the household sewer. If a blockage occurs, a safety pressure switch shuts down the furnace to prevent condensate overflow and water damage. A technician can resolve the blockage and take the needed steps to prevent recurrence, such as resetting the switch and restarting the system.
  • Burner ignition failure is often a symptom of a clogged vent pipe. High-efficiency models convey cool gases out of the home via a horizontal plastic pipe that usually vents to the outdoors through an exterior wall. Blockages in this pipe can also cause the pressure safety switch to shut down the system. Tracking down and removing the source of the blockage can permit the furnace to resume operation.
  • Weak burner flame is usually related to an inadequate supply of combustion air. High-efficiency furnaces induct outdoor air for combustion through a dedicated intake pipe. Insects, birds or leaves may clog the intake pipe, strangling the sealed combustion chamber of air that supports the burner flame. An HVAC technician can snake the intake pipe with a plumber’s augur and clear obstructions.
  • Another cause of a weak flame is if furnace exhaust gas is sucked into the fresh air intake pipe. This may result from insufficient spacing between the termination points of the two pipes. Most furnace manufacturers specify 12 to 14 inches of separation to prevent intake of exhaust gases.

In Yuma, ask the professionals at Hansberger Refrigeration & Electric Company if you require service for your high-efficiency gas furnace.

Our goal is to help educate our customers in Yuma, Arizona about energy and home comfort issues (specific to HVAC systems). For more information about gas furnaces and other HVAC topics, download our free Home Comfort Resource guide.

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