Top-Rated HVAC Contractor in
O’Fallon, Missouri

Travis was very helpful with our regular maintenance, and walked us through when we needed a new system.

Great company to deal with. Dalton was great from Stay Cool. He Answered all my questions and was knowledgeable.

Alex was awesome! He came out for my AC and heating tune-up, cleaned my humidifier, and somehow managed to explain everything in a way that actually made sense to me. He was super thorough, answered all my questions, and made sure I actually understood what was going on with everything before he left.

Bonus points for explaining it all without losing me somewhere along the way 😂

We love the technicians and service from Stay Cool. Alex was our guy this time around and he was great. They are friendly, honest, and knowledgeable. Even with our yearly checks, they never disappoint.

We have the bi-annual maintenance plan through Stay Cool. We moved into our 100 year old house last year. I found their info on the furnace and called to see if they could still service our HVAC. Our address was still in their system and they gave me a complete rundown of installation dates, services provided and service plans. Having just moved out of another home in which we had to (expensively) replace the HVAC as a condition of sale, I took them up on the plan. The techs (most recently Alex Larson) have all been professional, informative and they all dig our dogs! Happy to recommend them.

I highly recommend Stay Cool Climate Control. Everyone from the office to the technician is extremely courteous and professional. I highly recommend Stay Cool Climate Control.

They made a special effort to help me out during a high volume period of service calls due to 100 plus degrees weather. It all worked out and i was up and running within 3 hrs of calling them.

I came home to find AC blowing warm air, so I called to schedule an appointment. Dalton and Landon showed up 40 minutes later. They diagnosed the problem, had it fixed and my AC serviced within 45 minutes. They checked the whole HVAC system to make sure everything was functioning properly. They were professional and tried to keep the price as low as possible. I am very happy with the service I received.

Excellent Service, Very Quick, and Professional, What was quoted was what was billed no surprises, cannot recommend enough! They are the best around!

Had A/C and furnace installed by Johnny and Nathan. Top notch crew highly recommend

Great service, fair prices. Alex Larson came out had the issued diagnosed and fixed all in about an hour. Would highly recommend. Thank You

Very Quick efficient and reasonable. We made a call at 6:30 AM and by 10:30 AM. Our system was fixed on a holiday weekend. Alex our tech was very friendly and professional! We went ahead and signed up for the plan and look forward to working with them to help keep our home comfortable.

Same day service, on time arrival, very friendly and professional.

Always exceptional service from the scheduling to reminders and arrival notifications, to professional quality on-site work. We're never left with questions or worry, instead feeling comfortable and confident in the work and in the service / product we received. Jacob the technician was professional, courteous, informative and friendly. Highly recommend 👍

Alex went above and beyond what I was expecting.

The whole experience with this company was extremely pleasant! I called after hours last night to book & they came out first thing this morning. Alex, our technician was super friendly, helpful & explained every option super well. 10/10 recommend!

We are impressed by how good Stay Cool Climate Control were to do business with. We had a zone system installed and Jeremy was very good at explaining the details of exactly what and how they would do the installation. Nat and Zack were very professional on the installation and cleaned everything up completely. Their pricing was very reasonable and honored my veteran service.
6/17/2024 I was so impressed with Stay Cool I signed up for their maintenance plan and Braden came out and did a spring check and cleanup. He was great and explained everything.
7/8/2024 I continue to be impressed with Stay Cool and the way they follow through with their customers.
7/17/2024 The new Nest thermostat was defective (wasn't charging the backup batteries) but otherwise was still working and Stay Cool immediately ordered a new one and replaced it. Their customer service is the best I've seen.
Update 11/27/2024: Service call. Stay Cool came right out for a service call and Braden did a great job. Thank You
Update 12/11/2024 Had Stay Cool install a Humidifier by Cole. Awesome job as usual. Love these people.
Update 11/7/2025. Cole came out for winter service. Cole is great and appreciate all his input.
9/3/2026 Awesome as always. Dalton is great, Thank You!

Absolutely great experience. Responded fast and the tech was awesome.