Bryant, Trane and American Standard furnaces needed repairs the least often, according to the Consumer Report survey of 32,251 appliances bought by subscribers of the magazine. Many other brands, including Carrier, Rheen, Ruud and Lennox, held up nearly as well. Consumer Reports also has excellent general advice about purchasing a gas furnace.
Consumer Reports has never done a large survey of wood or pellet stove reliability, although they did test and review 6 pellet stoves in February 2011. The magazine gave highest rating to the Harman P68, which, at $3,900, was also the most expensive of all the pellet stoves they reviewed. A close second to the Harman was the Napoleon NPS40 which cost only $2,350, and rated higher than 3 other more expensive models from Lopi, Enviro and Quadrafire. At the bottom of the list was Summers Heat 55-SHP10L, made by Englander, but that model only cost $1,300 and is often considered a good value.
Consumers Reports has never tested wood stoves, so don't subscribe thinking you will find any ratings or recommendations for wood stoves. Both wood and pellet stoves deserve far more attention from consumer organizations as there is little reliable third party testing and reliability surveys. The testing that Consumer Reports did of pellet stoves in 2010 did not include efficiency, reliability, noise levels for pellet stoves or how much electricity the stove drew. The Alliance for Green Heat will be testing popular pellet stoves in the fall of 2015. See here for more details. The Alliance is also pursuing actual efficiency data of pellet stoves from the EPA, who initially declined to release the actual efficiencies of popular pellet stoves. The Alliance asked the EPA for a final determination on this matter and still hopes that the EPA will release this data.
Wood stoves are inherently more reliable and often need little repair, other than cleaning the chimney annually and replacing the gaskets every few years. However, the durability of many wood stoves, while a selling point, can also be a drawback because many people keep their old, inefficient and polluting stoves for too long, not realizing that newer ones can save them up to 50% on fuel cost and be far better for their health.