ConsumerSearch.com has rated the top furnaces that are currently available and offers side-by-side comparisons, as of August 2015. The review site and others like it also offer helpful tips for picking the best furnace based on your home's needs.
Another valuable website for furnace reviews is hvac-for-beginners.com. The author is an HVAC repairman and has shared a section titled Brand Reviews, in which gives his review of the major furnace and air conditioner brands.
Retailers such as Home Depot and Lowe's provide product reviews on their websites from customers that have purchased furnaces from them.
When deciding on what furnace to purchase for your home, it is best to consult with a qualified heating and cooling technician. Someone trained on sizing and installing furnaces is able to help you determine the best furnace type, size and efficiency rating to meet your budget and the needs of your home. Depending on the age and condition of your furnace, it may make more sense financially to have your furnace repaired rather than replaced.