Welcome to Markgraf's Heating & Air Welcome to Markgraf's Heating & Air home on the Internet! For more than 40 years, we've been helping folks throughout the Chicagoland area enjoy total indoor air comfort in their homes and businesses. Our many satisfied customers tell the story, but for your added peace-of-mind, be rest assured that our professional staff has received the most up-to-date training available. So whenever you need us, we're here for all of your heating and cooling concerns -- from scheduled maintenance & repairs to installations with a smile, we're always just a phone call away. • Free estimates • Telephone quotes • All major credit cards accepted.