Markl & Sons Cooling and Heating

Markl & Sons Cooling and Heating has earned a 4.8-star average across 101 verified reviews, placing it among the most recommended contractors in Grayson County. Based in Sherman at 119 East Brockett, the company serves both Sherman and Denison residents with residential and commercial HVAC solutions. This family-operated business has built its reputation on rapid response times and transparent diagnoses, earning repeat business and referrals throughout the region.

The contractor distinguishes itself through comprehensive indoor air quality offerings that many regional competitors omit, including UV light installation, coil cleaning, programmable thermostat setup, and zoned comfort control systems. Website mentions confirm they handle new construction installations alongside repair and maintenance, with service agreements available for ongoing system care. Their AC Help Center provides educational resources covering heat pump operation, energy savings, and HVAC terminology, suggesting a commitment to informed customer decision-making.

Customer reviews spotlight specific team members handling urgent situations. Technician Randy arrived within hours during a summer breakdown and presented three repair options without pressuring an upsell, while Kenny and Tim worked past 7 PM to ensure proper installation. Joe resolved a residential issue in under an hour, providing maintenance advice to extend equipment life. Reviewer Laura Skinner recounts an act of honesty when the owner personally returned a misplaced business credit card, calling her workplace to arrange pickup, underscoring the personal accountability that distinguishes smaller operations.