Contact Us Cosby Heating and Cooling 10 College St. Mt. Vernon, OH 43050 740-393-4328 Thank you for your interest in Cosby Heating and Cooling and a geothermal comfort system. Please fill out the form below and someone will contact you shortly. We'll answer any questions you have and can provide you with a free estimate for your unique geothermal situation in Knox County and the surrounding region. Required Required Not a valid email Required Not a valid phone number Favorite Color Your Name Favorite Highway