I live in the Bay Area and want to replace my gas furnace. It was installed when my 1340 sq.ft. house was built in 1978. I don't have A.C. A new state regulation became effective October 1st requiring homeowners in my town to purchase a high-efficiency furnace or have the duct work inspected, and if necessary, sealed.
I have three bids, ranging from $X to 1.5 times $X. They all recommend the high-efficiency furnaces to avoid the duct-work requirement - which they all say can be more expensive than the furnace. Manufacturers range from Amana Multi-Speed (AMS9), RUUD Achiever 90+, Carrier Comfort 92, and a TRANE.
Comsumer Reports has not tested gas furnaces in recent memory and essentially advises consumers to do their homework, get three bids and check references. It also says that the high efficiency condensing furnaces are more complex and more prone to problems. I have never had any problem with the existing furnace.
If references check out, I'm inclined to go with the Amana or the RUUD. Is there anything else I should know?