Consumer and expert furnace reviews of specific models are scant, partly because of the vast array of furnace sizes and types available, but also because it can take a decade or more to properly develop a furnace review that evaluates how well a unit performs and how reliable it is. That said, some sites do comment on furnace brands in terms of their overall performance and reliability and provide some furnace reviews.
Overall Performance and Reliability.As long as you don't live in an extremely cold region, you can't beat the Trane XL80 series of mid-efficiency (80% AFUE) furnaces, one of our picks for best furnaces, according to experts at Galt Technology. Furnace reviews by consumers and HVAC experts at FurnaceCompare.com seem to agree, noting that most problems with Trane furnaces come from mistakes during the installation process. In a survey by Consumer Reports, Trane furnaces have a slightly better service and reliability history than most other furnace brands.
Older high-efficiency furnaces produced by Carrier were the subject of a now-settled class action lawsuit, which asserted that a critical component in the furnace (the condensing heat exchanger) was manufactured with inferior materials and failed before the end of its expected 20-year lifespan. However, new Carrier furnaces (sold after 2008) are not part of the complaint, nor were less efficient Carrier models (with an AFUE lower than 90%). A contractor who posted a furnace review at FurnaceCompare.com installs many Carrier Infinity 96 units and says he always trusts and recommends them because they last a long time with no trouble.
Payne furnaces impress the team at WebHVAC, which says the brand has a superior track record in reliability and performance and is backed by one of the best warranties in the business. While consumer reviews are mixed at FurnaceCompare.com, a couple of contractors posting furnace reviews say installation is most likely to blame for recurring problems. One reminds consumers that furnaces, like cars, need regular maintenance to keep running smoothly.
Lennox earns reasonably good appraisals across the board on the furnace reviews site FurnaceCompare.com. Its Merit series is certainly the most affordable, and users posting on GardenWeb forums say these furnaces do what they're meant to do. But if you can afford to spring for the Lennox Elite Series (starting at $4,200), you'll get a much higher AFUE rating (up to 92%) and could save money on monthly heating bills over the years.
Goodman furnaces (starting at $1,500) came under fire several years ago when a comparative furnace ranking of repair histories by Consumer Reports (based on reader responses to a survey) indicated that Goodman units were less reliable than 10 other major furnace brands. However, Goodman seems to have corrected many of the problems, according to forum users and new customers posting furnace reviews on GardenWeb and FurnaceCompare.com. Still, experts note that more time is needed to assess the reliability of the new Goodman models, and Ask Me Help Desk suggests springing for an extended warranty if you buy a Goodman furnace.
Furnace Installation.Other performance characteristics, such as noise level and comfort/temperature, are difficult to assess because they are heavily dependent on how the furnace is installed and whether it's the correct size for the house. Homeowners occasionally comment on these matters in gas furnace reviews, but because of the inherent differences among houses and installers, we determined that such remarks are not particularly helpful when you're deciding which furnace to buy.
Indeed, the HVAC contractor you use can have the biggest effect on the performance of your furnace. Talk with friends and co-workers or ask your local gas utility for recommendations, then crosscheck those recommendations against consumer reviews of the contractor at online review sites such as YellowPages.com and ServiceMagic. If you have the time, get estimates from a few different contractors. Any contractor you use should be able to show you proof of bonding and insurance, plus any required contractor's licenses and certifications by trade organizations, such as the North American Technician Excellence or HVAC Excellence.
Remember, getting the most efficiency and comfort from a cheap furnace also depends on the duct work and weatherproofing around your home. Ask your installer to check your ducts for any leaks and to seal them up, and take measures to reduce drafts around your home with techniques such as weather-stripping or upgrading to better doors and double-pane windows.