No matter how much research you do about different heater features and specifications (and you should do a lot) it can’t be a replacement for the real life experience of a contractor who has installed tens or hundreds of furnaces in homes similar to your own. Read all the consumer reports you want on different makes and models (and yes, do read them!) but having a relationship with the person who is responsible for installing them and repairing them will definitely aid you in making the right purchase installation decisions.
That said, often contractors have a relationship with a certain manufacturer and are only available to install models of that brand. This is alright since there are a lot of good brands available to you, but part of your preliminary research should definitely be knowing what brands are acceptable to you and which are not as this will be the first thing that will limit which contractor you want.
Now start to build your list of contractors. You can start with the yellow pages, but that might be a bit overwhelming and random. The best bet of course is personal recommendations. Friends and neighbors, especially those with homes and needs similar to yours are going to be a good resource here. Don’t be shy, when people really like or dislike their contractor they love to talk about it. Look for the enthusiastic reports (positive or negative) and use those to build or shrink your list.
