Top-Rated HVAC Contractor in
O’Fallon, Missouri

I had a great experience with Stay Cool! They were able to come check my heater the same day I called, and checked all of the heating and cooling systems. I needed a new water heater and furnace - I didn’t feel pressured or like they were trying to upsell. Two days later, Dalton and Neil came to replace those two systems. Everyone I talked with was very professional and knowledgeable. I would absolutely recommend Stay Cool!

Very happy service did a great job. Highly recommend. Very professional and knowledgeable. Excellent job

We are new customers and are very impressed after our first maintenance visit! Travis was not only punctual and polite, he was also very knowledgeable and thorough. So thankful to find a local, family-owned company and have an exceptional experience!

These gentlemen were so nice and fixed my furnace/ac unit in my mobile home. Will be definitely referring people to them! Thank you guys so much!

Service was excellent!!

Fast, polite, economical service at a great price! We also have their service contract to keep our heating and cooling system in top shape year-round.

Travis and Jacob and the other tecnicians were polite, and knowledgeable. They explained what they were doing. I now have a working furnace. They came in a timely manner.

Travis and Jacob and the other tecnicians were polite, and knowledgeable. They explained what they were doing. I now have a working furnace. They came in a timely manner.

Installers were very noticeable about the installation.explain in detail about My New unit I'm very pleased with My New unit

NEW - update! 02/10/2026 : Dalton came out and was on time, courteous, and very well knowledgeable about my issue. He prescribed the right maintenance for my unique situation and made it simple to decide next steps. In & out! Also want to shout out Cindy for her great customer service and promotion of Stay Cool’s $79 furnace special right now! No pushy sales just quality maintenance and support from a great team of experts! Would highly recommend! ————————————— (Past experience) Jeremy & Nate were both professional and very informative of options I have for Replacement smart thermostat in addition to overall, maintenance tips. They had a pleasant, friendly nature and I would recommend them to neighbors and friends. I appreciated the ease of scheduling and the follow-up call from the office prior to the techs’ arrival too. Definitely a company I will keep in my pocket for future HVAC services.

Travis , the technician, came out in very polite and professional and identified 2 problems I was experiencing with my furnace. The last few days have been very chilly. He stated what was needed and the price it would involve. With recommendations to plan on if other problems arise. He had to gather equipment needed to get the repair done he was quick and fastidious in his service and informed me when it was completed. Was very happy with the results. My furnace is running again and I’m warming back up. Thank you Stay Cool HVAC for you service.

Brandon and the other guy were great! Quick install, reasonable pricing, and went over everything done. Definitely recommend.

Jake and Trey were fantastic. Highly skilled and efficient and super nice dudes. We have used Stay Cool multiple times now including a furnace install. Their quote was spot on, they showed up when they said they would. Great experience. Travis was also super helpful in navigating a new furnace. We will be using them again when our other furnace finally dies. Thank you!

Excellent job and detail replacing my HVAC. They treated me like family from pricing to installation and service.

Dalton was amazing, couldn't ask for a better tech!

Dalton was amazing!!!

Travis was great! He not only worked quickly, but talked me through everything he was doing, gave maintenance tips and made sure I knew everything I needed to know before he left! He was friendly, prompt, and so helpful! I would absolutely recommend StayCool for any HVAC needs!