Top-Rated HVAC Contractor in
O’Fallon, Missouri

Travis is very nice and he explained everything to me regarding the issues. I love this company and highly recommended. Very professional and nice people and easy to talk to. Thanks to James and Carter also. Cole fixed my home humidifier yesterday 10-21-2025 and Jacob just got done replacing the gas Valve in my furnace - They both did an amazing job. Very kind people and very professional. Highly recommend this company. Amazing customer service as always.

Jacob was very professional and courteous. Let us know the return air to the blower was undersized. Recommended we replace the blower in the future if necessary rather than replace expensive ductwork now.

Peter was fantastic. Came in to our shop and addressed the problem almost immediately with our heater. Then made several recommendations on future maintenance techniques to keep us warm through the winter. Thanks so much stay cool!

Cole was excellent and professional.

Thank you to the whole family at Stay Cool for making it painless to switch over HVAC services to them! Cole came and serviced our heater and took the time to explain how to be proactive when it comes to maintaining the system. What a pleasant and respectful person he is. Highly recommend these folks!!!!

Brandon, Jason, and Carter were great and very professional when installing my zoning system and repairing my air conditioner.

Peter did a great job working on the air-conditioner last month and installed a new carbon monoxide sensor today. He is extremely professional and friendly. Could not ask for better service.

Awesome team. Jason and Nathan are the best!

This was our first experience with this company and we were very happy with the service That Cole provided. We will definitely be using this company in the future.

Very professional and on time. Very fair and price.Cole always does a great job. Cole has amazing customer service

They did a wonderful job on a very short notice. 10/10 experience and will definitely be using Stay Cool for future HVAC needs!

This morning, Peter came in and did regular preventative maintenance on my furnace. He was very professional and efficient. He did explain certain maintenance procedures that would help in extending the life of my furnace. I highly recommend this company and their guys. 👍👍👍

I am a service plan customer. I have had nothing but exceptional experiences with Stay Cool. The office has been so kind and accommodating a last minute reschedule request on my part. Cole has always been prompt, professional and super knowledgeable.

We recently had our blower motor fail. Jacob was able to get a new part for our A/C and get it running in no time. Cole also came out for a furnace tune up and laid out all of our options very well. I've always found Stay Cool to be trustworthy and reasonable in price. Thanks guys!

Cole did awesome job on my mini splits!! He offered best things that needed be done.. now I can keep up wit my yearly maintenance!! I will be keeping this company in my contact for when I need them.. thanks so much!! Really appreciate it!!

Cole was very friendly and respectful of our home. Extremely knowledgeable and straight to the point with services being done and pricing for everything being done!

Had Cole come out recently and he did a great job explaining everything

Jacob was great! He was friendly, professional, and got the job on our furnace done quick.