A gas furnace has an average service life of more than 15 years. About 20 percent of gas furnaces are still working at the 20-year mark. However, “service life” simply means the span of time during which the unit still starts up and generates heat. Many homeowners may wonder whether an aging furnace that’s still technically functioning should be kept on the job or replaced. Here are some considerations to help you make that call:
Efficiency Now
While an older furnace may still generate heat when you turn it on, that doesn’t mean you’re getting energy-efficient operation. In fact, a furnace manufactured before 1992 probably came off the assembly line with an AFUE (annual fuel utilization efficiency) rating of 65 percent or less. As your unit ages, efficiency declines even further.
Today’s new AFUE 80 furnaces deliver energy savings and lower operating costs from day one. If you opt to upgrade to a high-efficiency condensing furnace, you’ll receive AFUE ratings above 90 for even greater savings.
Dependability Issues
At some point, it’s no longer financially viable to keep an existing gas furnace working. Major components like the heat exchanger—a part that typically fails due to age—are rarely worth replacing on a unit approaching the end of its expected service life. However, even increasingly frequent and expensive minor repairs can push the repair-or-replace issue past the tipping point.
Comfort Matters
Your old-school furnace probably incorporates a single-speed, on/off blower fan and a one-stage burner. This means you’re putting up with indoor comfort that belongs to the 20th century, not the 21st. Today’s variable-speed furnace blowers heat homes more consistently without drastic temperature swings as warm air cycles on and off.
Two-stage burners automatically sense and adjust to changes in your home’s heating load, providing full output to warm a cold home quickly. Afterwards, it automatically shifts to single-stage output to fine-tune indoor temperature and comfort.
In the Twin Cities metro area, let the experts at Marsh Heating & Air Conditioning help you decide whether to repair or replace your aging gas furnace. Contact us today.
Our goal is to help educate our customers in Minneapolis-St. Paul, Minnesota 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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