Air Conditioning O’Fallon | HVAC Company O’Fallon

Gas Furnace HVAC Services

30+ Years

Experience

Master Technician

Locally Owned & Operated

24/7

Emergency Service

HVAC Services in O’Fallon, Missouri

Your Local Heating and Cooling Experts in O’Fallon

When residents of O’Fallon, MO need reliable heating and air conditioning services, they turn to Thomas Hoffmann Air Conditioning & Heating—the locally owned company that puts customer service first. With over a decade of experience serving homeowners and businesses across the St. Louis metro, we understand what it takes to keep your home comfortable in Missouri’s unpredictable climate.

Whether you need emergency HVAC repair, a seasonal system tune-up, or a full replacement, our certified technicians deliver honest, high-quality service—no gimmicks, no corporate call centers.

Why O’Fallon Homeowners Trust Us

  • Local Company, Local Team
    • We’re based right here in the St. Louis area—no out-of-state investors or rebranded franchises. We know O’Fallon homes because we live and work nearby.
  • Fast & Responsive Service
    • With flexible scheduling and same-day availability, we make it easy to get the HVAC service you need—when you need it.
  • Upfront Pricing with No Surprises
    • Our estimates are clear and competitive. You’ll always know exactly what to expect before any work begins.
  • Trusted, Experienced Technicians
    • All of our technicians are fully licensed, EPA-certified, and committed to doing the job right the first time.

Our HVAC Services

Furnace Repair & Installation

Strange furnace noises or uneven heating? We service all major brands and offer repairs or replacements to restore comfort. Energy-efficient upgrades are also available to help lower heating bills.

Air Conditioning Repair & Replacement

If your AC isn’t cooling or cycling too often, we’ll diagnose and fix the issue quickly. We also install complete AC systems tailored to your home. Same-day service is frequently available.

Indoor Air Quality Solutions

Breathe cleaner air with whole-home purifiers, humidifiers, and ventilators. Our solutions reduce dust, allergens, and stale air—ideal for older homes or allergy-sensitive households.

HVAC Maintenance Plans

Keep your system running smoothly with a maintenance plan. We offer seasonal checkups to extend system life, prevent breakdowns, and help you stay prepared year-round.

We Serve All Neighborhoods in O’Fallon

Whether you’re in WingHaven, Twin Chimneys, Dardenne Prairie, or near Highway K and Mexico Road, our team is familiar with the heating and cooling challenges unique to O’Fallon homes. From newer builds to older properties, we tailor every solution to fit your system and your budget.

Book HVAC Service in O’Fallon Today

Don’t let heating or cooling problems disrupt your comfort. Whether you need fast repairs, better indoor air quality, or expert advice on a new system, trust the O’Fallon HVAC pros at Thomas Hoffmann Air Conditioning & Heating.

📞 Call (314) 471-7625 or Request Service Online to schedule your appointment today.

What Your Neighbors Are Saying

Richard T.
1 week ago
Fast professional and curtious. I am so happy with the work and the energy. Thanks-Richard
Response from the owner:Thank you, Richard! We're grateful for your kind words and glad to hear you appreciated the work and energy of our team.
Mari L.
3 weeks ago
I’ve been using “THOMAS Hoffmann Airconditioning and Heating LLC” for years now. We have a 30 +\- year old system that works perfectly for us. Although we’ve not had to use it yet, it is comforting to know they offer a 24 hour on call service. I really appreciate that the technicians don’t try to upsell us on anything. They’re a very professional, knowledgeable, and courteous, local-family owned and operated business. I’ve also found their pricing to be very fair and by”fair” I don’t mean “cheap” but reasonable… especially for the quality of service provided by THOMAS Hoffmann HVAC. I love supporting smaller family owned business and this one is top-notch! Thank you guys!
Response from the owner:Thank you so much for your continued support and kind words, Mari! We truly appreciate your loyalty and are glad to hear about your positive experiences with our services. We look forward to continuing to provide you with top-notch service in the future.
James H.
3 weeks ago
Came out immediately after a time slot opened and fixed the AC issue.
Response from the owner:Thank you, James, for your kind words! We're glad we could address your AC issue promptly.
Margaret F.
3 weeks ago
Excellent service from Nick! Friendly was super knowledgeable!
Response from the owner:Thank you, Margaret! We appreciate your kind words and will make sure to pass along your praise to Nick for his excellent service.
Teresa F.
4 weeks ago
Our service technician arrived right on time and was professional, friendly, efficient and courteous. We couldn’t ask for more.
Response from the owner:Thank you for sharing your positive experience with our service technician! We appreciate your kind words and are glad to hear that you were satisfied with the service provided.
Marilyn H.
1 month ago
Nick was was great! He provided great service, explained everything, and was patient and kind.I definitely recommend using Hoffman!
Response from the owner:Thank you, Marilyn! We're glad to hear that Nick provided you with excellent service and made your experience enjoyable. We appreciate your recommendation!
Jasmine W.
1 month ago
The whole team was great, professional and friendly. Scheduling was easy and well organized, they had many options for different price points and financing options. Thank you!
Response from the owner:Thank you for the thoughtful review, Jasmine! We appreciate your support and continued business.
Henry D.
1 month ago
I have complete trust in Thomas Hoffman AC . I have had multiple technicians who are always polite and knowledgeable.
Response from the owner:Thank you for your trust in our team, Henry! We appreciate your kind words about our technicians.
Theresa S.
1 month ago
Love that it’s the same technician every time. Let’s me know what he found and any concerns he might have regarding our units. Great customer service.
Response from the owner:Thank you, Theresa! We're glad to hear you appreciate having the same technician and the communication about your units. Your feedback on our customer service means a lot to us!
Frank P.
1 month ago
From the phone to the completion of the job everyone is so polite and informative. I had Giovani as our representative and he was very informative and professional, and knew exactly what the problem was. Thanks so much.
Response from the owner:Thank you for the kind review, Frank! We appreciate you and your business.
Allan G.
1 month ago
Zach did an excellent job! Always courteous and friendly. We would highly recommend calling Thomas Hoffmann HVAC for any heating and cooling needs.
Response from the owner:Thank you, Allan! We're glad to hear that Zach provided excellent service and appreciate your recommendation for Thomas Hoffmann HVAC.
William W.
1 month ago
Was able to locate the problem right away and replace a switch and add Freon very nice job by this employee. I will recommend Thomas Hoffman for future references.
Response from the owner:Thank you, William! We're glad to hear that our team was able to quickly address the issue and that you had a positive experience with Thomas. Your recommendation means a lot to us!
Jack D.
1 month ago
I had Nick come out. He was awesome. Very knowledgeable, prompt and helpful. I will definitely recommend Thomas Hoffmann HVAC to others in need of HVAC support.
Response from the owner:Thank you, Jack! We're glad to hear that Nick provided you with excellent service. We appreciate your recommendation and look forward to assisting you and others in the future.
FFE L.
1 month ago
From our initial quote until the new furnace and AC were completed, everything was smooth and efficient. Zachary and Giovanni were excellent on-site, taking time to explain the installation as well as leaving the home clean. Thank you Thomas Hoffmann team
Response from the owner:Thank you! We're glad to hear that the installation process was smooth and efficient. Zachary and Giovanni will be pleased to know their efforts made a positive impact. We appreciate your kind words about the team!
Bob De P.
1 month ago
Courteous friendly and efficient! What else could you want!
Response from the owner:Thank you, Bob! We're glad you found our service courteous, friendly, and efficient – that's exactly what we strive for!
Princess C.
1 month ago
Update 4/6/26: Zach Sperling is such a pleasant and knowledgeable technician that I recommend him highly. Thomas Heating has been a wonderful company to work with in my maintenance plan. If you are looking for a reputable company, look no more. This company is so responsive that I love them. They respond immediately, and I trust them to tell me what needs to be done. I haven’t been steered wrong yet. They are genuinely nice to work with and honest. I use their maintenance program which I highly recommend.
Response from the owner:Thank you for your kind words, we truly appreciate your trust in us and are glad to hear about your positive experience with our services.
Julie N.
2 months ago
So helpful! Straight into the point with no runaround or Negotiating up sells! Quick and efficient!
Response from the owner:Thank you for the great review, Julie! We appreciate your business and the support!
George G.
2 months ago
Great fast courteous service, knowledgeable.
Response from the owner:Thank you for recognizing our fast and courteous service, we appreciate your feedback!
harold B.
2 months ago
work good but got at least 6 messages from them very annoying
Response from the owner:Thank you for your feedback, Harold. We appreciate your input and understand how too many messages can be frustrating. We'll work on improving that experience for you.
Philip D.
2 months ago
Nick was great! He came right out and was able to solve the problem fairly easily. He communicated well and helped us prevent a future problem as well.
Response from the owner:Thank you for the review, Philip! We are happy to hear you had a pleasant experience working with us.
Pat Keith T.
2 months ago
Geovanni is great!
Response from the owner:Thank you, Pat, for your kind words about Giovanni; we appreciate your feedback and are glad to hear that he made a positive impression.
Greg D.
2 months ago
They have never failed to fix my hvac problems. These folks are top tier.
Response from the owner:Thank you for the wonderful feedback, Greg! We're glad to hear that you've had such positive experiences with our team. Providing timely and effective service is our priority, and we're here whenever you need us. Looking forward to assisting you again!
Amy K.
2 months ago
Giovanni was very professional, helpful, patient and helped me figure out the issue, if it was covered under warranty, and next steps. Great overall experience and much appreciated.
Response from the owner:Thank you, Amy! We're glad to hear that Giovanni provided you with such professional and helpful service. Your appreciation means a lot to us!
Joe G.
2 months ago
Always professional and thorough whenever they service our home. We have used Thomas Hoffmann Air Conditioning & Heating multiple times since we moved into our home and will continue to use them in the future.
Response from the owner:Thank you for the thoughtful review, Joe. We appreciate you and your business!
Daniel D.
2 months ago
Met Nick at ACCA - conference for HVAC contractors. He’s an expert! 100% 14 years in the business, doing a great job and service.
Response from the owner:Hi Daniel! So happy to hear you enjoyed Nick's company. We are lucky to have him.

24/7 Service Call Now

At Thomas Hoffmann Air Conditioning & Heating, we pride ourselves on being a locally owned and operated HVAC company. With more than 30 years of experience and a master technician and mechanical engineer as our owner, we can replace, repair, and maintain your business or home’s HVAC system.