Ask friends or family if they can recomend someone. Tell them that you are interested in a new heating system and that you would like a load calculation done to determine the proper size equipment for your home. Get two or three estimates from licensed and insured mechanical contractors and make sure a permit is pulled and the job gets inspected.
“Now the freaks are on television, the freaks are in the movies. And it’s no longer the sideshow, it’s the whole show. The colorful circus and the clowns and the elephants, for all intents and purposes, are gone, and we’re dealing only with the freaks.” - Jonathan Winters