Over 42 Years of Honest HVAC Excellence
Our Story
Cornerstone Heating & Air Conditioning, Inc. was founded over 42 years ago with a simple commitment: do the job right the first time. Based in Frederick County, MD, our company holds Maryland Master License MD-6477, certifying our master-level expertise across gas, oil, steam, and electric systems.
We maintain a BBB A+ Rating by prioritizing clear, upfront pricing and transparent technical diagnostics over pushy sales tactics. Whether servicing classic hydronic steam boilers or installing green geothermal systems, we treat every customer like family. Rely on our legacy of honest mechanical service across MD and PA.
Our Customer-First Service Workflow
Enjoy smooth, stress-free HVAC repairs and installations with our straightforward process.
Easy Scheduling
Contact us at (240) 674-3100 or online during office hours (Mon–Fri 8:30am–5pm, Sat 8:30am–12pm) or request 24/7 emergency dispatch.
Professional Diagnosis
Our certified tech evaluates your system using digital gauge manifolds.
Upfront Quote
You receive clear repair or replacement options with zero hidden charges.
Skilled Service
We complete the work, test all safety controls, and leave your workspace clean.
Why Choose Cornerstone Heating & Air Conditioning, Inc.?
42+ Years of HVAC Experience
With decades of hands-on expertise, we bring unmatched knowledge and problem-solving to every project — from routine tune-ups to complex system installations.
Certified, Skilled Technicians
Our team is professionally trained and certified, including factory training with top-tier brands like Bosch. We do the job right the first time, every time.
Custom Solutions for Your Comfort
No two homes or systems are alike. We assess your unique needs and provide tailored heating and cooling solutions that maximize efficiency and comfort.
Flexible Financing Options
We offer convenient financing plans (with approval) to make your HVAC investment manageable — without compromising on quality or reliability.
Our Guarantee of Quality Service
Operating under Maryland Master License MD-6477, Cornerstone Heating & Air Conditioning guarantees that every installation and repair meets strict local building codes. We inspect all electrical connections, safety cutoffs, and refrigerant lines to ensure your long-term safety.