Delaware's premier residential HVAC installer
Mon - Sat 8:00 - 5:00        


Delaware Heating & Air Conditioning

Our goal is to ensure the complete satisfaction of every customer by using a personal approach while providing efficient, courteous and professional service at competitive rates. Serving Kent and Sussex counties, every job, big or small, is important to us as we focus on customer care and reliability.

Don’t get left out in the cold

Give us a call today and get your free estimate!


When your HVAC system breaks on the day a 90-degree heat wave (or a single-digit polar vortex) is scheduled to arrive, don’t waste a minute and call Gillespie HVAC right away. We take the comfort of our clients seriously, which is why we offer emergency repair service for HVAC issues.


Whether you are replacing an old or failed HVAC system or looking to install high-quality, durable equipment in a new construction project. Gillespie HVAC can provide these quality HVAC installation services to Kent and Sussex Counties. Give us a call today to schedule your free estimate.


Maintenance is not only for older HVAC systems. Having regular maintenance completed on new systems is essential to keeping their performance maximized and also required to keep manufacturers warranties in place. We offer both one time plans and comprehensive annual agreements.

Why Choose Gillespie HVAC?

There are many Delaware HVAC service companies that provide heating and air conditioning installation and maintenance services in Kent and Sussex counties. Here’s what makes Gillespie HVAC different and why so many Delaware residents trust us with their HVAC equipment:

Fair and Honest
Our longstanding reputation as a fair, honest, and respectable company has earned us a growing number of long-term customers and widespread word of mouth referrals. We take pride in keeping that reputation.

Quality Products
We use only the most solid, reliable, and reputable products from the leading manufacturers. We will never recommend you a product we haven’t tried before or have doubts about. Your satisfaction is our goal.

Our highly-trained technicians who install and maintain HVAC systems are the reason why we firmly stand behind our installations. If there’s ever a problem, we will work to resolve it promptly and efficiently.

We consider it our responsibility to help you make an informed decision in regard to the best HVAC equipment for your needs. That’s why we are always here to answer questions and provide professional recommendations.

Winter is the season in which people try to keep the house as warm as it was in the summer, when they complained about the heat.

What Our Clients Say…

“Very pleased with the service provided. The technician was very knowledgeable and resolved the problem quickly. He was also very courteous, answered all the questions I had on our new system”

joe-bloggsKaren Whitfield – Milton, DE

How your HVAC system operates