Hours: We are open 24/7

2183 West Terra Lane, O'fallon, MO 63366

(314) 513-0385

How can we help?

A name you can trust

Serving O Fallon, MO & surrounding communities.

We offer a complete suite of HVAC services for your home. Whether you need quality air conditioning or heating service, we’re here for you.

(314) 513-0385 Tax Credits FAQ

$50.00 Off Air Scrubber Air Cleaner
Discount good with coupon only. Not valid with any other offer.
$25.00 Off New Humidifier Installation
Discount good with coupon only. Not valid with any other offer.
$50.00 Off Water Heater Installation

Improve the efficiency of your heater

Discount good with coupon only. Not valid with any other offer.
$300.00 Off Complete Installation

When installing both new heating and cooling equipment

Discount good with coupon only. Not valid with any other offer.
Free! UV Light or Air Cleaner

With purchase of Infinity® System by Carrier

For a limited time only. Call for details. Cannot be combined with other coupons or promotions.
Furnace Replacement

Why pay for a costly repair on an old furnace? *Restrictions apply, Call for details.

Discount good with coupon only. Not valid with any other offer.
FREE! Service Call

With Any Repair or Replacement

For a limited only time. Call for details. Cannot be combined with other coupons or specials. Must present coupon to get the free service call.

we work hard to earn your lifetime business.

24 hour emergency service available!

Through dedicated customer service, skilled workmanship, and top-quality products, 314-513-0385 is the only number you’ll ever need for complete comfort. We provide precision installation, replacement, seasonal maintenance, and prompt repair of heating, cooling, air quality, and water heating systems, answering every residential and commercial challenge. Our NATE-certified technicians are committed to providing solutions quickly, as well as ensuring sustainable performance and lasting satisfaction.

(314) 513-0385Schedule Service

Why choose us?

Dedicated customer service
Skilled workmanship
Top-quality products
Seasonal maintenance
Prompt repair
NATE-certified technicians

Home and business owners in West St. Louis & St. Charles Counties have been turning to Reliable Heating & Cooling, Inc. to improve their everyday life for nearly 50 years.

Featured Services

Call Reliable Heating & Cooling, Inc. for all of your heating & air conditioning needs!



Air Quality


About us

Special offers

We are always on call

Dedicated HVAC Service Repairs, and Installations throughout West St. Louis & St. Charles Counties

The team from Reliable Heating & Cooling, Inc. is always on call to assist you in times of trouble.

We provide Emergency Service across St Charles, O’Fallon, St Peters, Wentzville & Lake St Louis, MO, 24 hours a day, 7 days a week, 365 days a year, as well as convenient appointment times during regular business hours. No matter what type of challenge you may face or requirements you may have, our specialists arrive equipped to handle the job. From new furnace installations to A/C maintenance and repair, we’re proud to offer a comprehensive suite of residential and commercial HVAC services. We maximize your satisfaction through rapid response, economical solutions, conscientious workmanship, and neat and tidy job sites.

(314) 513-0385Schedule Service

Reliable Heating & Cooling, Inc. is accredited with the Better Business Bureau, and is an Angie’s List Super Service Award Winner.

Established in 1972, we specialize in “green” energy-efficient products, helping our customers achieve their goals for lower operational costs and environmental responsibility. As a Carrier Factory Authorized Dealer, we are uniquely qualified to accommodate your specific requirements and install the most innovative and advanced options on the market. For year-round convenience, comfort, and control over your indoor environment in West St. Louis & St. Charles Counties, contact the professionals from Reliable Heating & Cooling, Inc. today! We are the name you can trust.

(314) 513-0385Schedule Service

Air Conditioning Installation, AC Service, Air Conditioner Service, HVAC Installation & AC Repair O Fallon, MO, Saint Peters, MO, Lake Saint Louis, MO, Wentzville, MO & Saint Charles, MO

AC Company O Fallon, MO | Air Conditioner Repair Saint Peters, MO | AC Contractor Lake Saint Louis, MO

AC CompanyHVAC CompanyHVAC ContractorAC Contractor ∴ O Fallon, MO ∴ Lake Saint Louis, MO ∴ Saint Charles, MO

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Customer Reviews
What our customers are saying

Have been with them for more than 10 years. They provide exceptional service…from the time they call to remind you about setting an appointment to the actual service day. Derek (and all their other technicians) are knowledgeable, professional, prompt, and open to listening to questions and pay attention to details. Never had a problem with anything. Thank you for a job well done. Good pricing.

Seema Chouhan

We had a emergency water leak problem with our AC unit in the basement of our recently purchased condo. Called Reliable and Derrick was there within a couple of hours. He was polite, knowledgeable, and friendly. Derrick quickly found the problem and repaired it. He also checked the system overall, pointed our some concerns and answered all my questions. I can’t say enough about how satisfied we were with Derrick and Reliable Heating & Cooling! We would definitely recommend them!!! Thanks again!!!!

Terry Mills

Had a small gas leak for a property I was helping a friend sell and we found out late last night. We reached out to Reliable H&C and Derrick was over first thing in the morning. He was friendly, professional and knowledgeable. He answered my questions with a smile. Derrick was a rock star. Will absolutely call him again. Bravo

Connor Kapp

I had a system malfunction on Sunday evening December 12, 2022 on my Carrier Infinity ICS purchased in 2008.I am a first time caller to Reliable. Marty called me back and had his Tech dispatched at 8 AM the next day. The unit had failed and was dangerous to use. He had a new system by the next morning. They installed it and I was completely satisfied with their service and response time. I overwhelmingly recommend Reliable and will be using them from now on.


Reliable has installed and maintained our last 2 furnaces and AC. Our experience with them has been great. Just yesterday we had an issue with our AC. I talked to Marty and he said he’d have someone out the next day. They even were able to accommodate us with an afternoon call. Derrick arrived promptly on time and had us up and going again in 15 minutes (bad capacitor on the condenser unit fan motor). With the prediction of high 90 temps, we were so thankful to have AC working again.

Keith Scherer

We have used Reliable Heating and cooling for all of our heating and cooling needs. We needed some water heater work and Ralph came out and took care of it right away. Ralph was very professional and knowledgeable. He got the job done very quickly and everything is working great! I always recommend Reliable to family and friends. They truly are Reliable!

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