4.7 
845 *The Angi rating for Heating And Air Conditioning Service companies in Saint Charles, MO is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Heating And Air Conditioning Service needs.
*The HomeAdvisor rating for Heating And Air Conditioning Service companies in Saint Charles, MO is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Heating And Air Conditioning Service needs.
Last update on October 20, 2025
Serving Saint Charles, MO and surrounding areas
Approved
In business since 1947
Free estimates
Emergency services offered
"The technicians are so nice and helpful, professional, and punctual. They've maintained my hvac for the three years I've lived in this house and all runs smoothly."
+106
Serving Saint Charles, MO and surrounding areas
Approved
In business since 1947
Free estimates
Emergency services offered
"The person who handled my call was friendly and professional. She told me a technician would be at my house in 4 hours and called me when he was on his way. The technician was outstanding, on time, professional, friendly, and quickly diagnosed and fixed the problem...best of all, he didn't try to sell parts/service that I didn't need! Best experience with an HVAC company I've ever had."
+2
Serving Saint Charles, MO and surrounding areas
Approved
In business since 2003
Free estimates
Emergency services offered
"A-ok! Dunn OneHour HVAC is always top notch!"
Serving Saint Charles, MO and surrounding areas
Approved (Corporate)
Super Service Award Winner
In business since 1979
Free estimates
Emergency services offered
"Great. Brandon knew his stuff. He conducted and airflow test to show us where our leaks were. He provided suggestions on where we could best reduce leaks. He also looked over our structure (joists) and HVAC system, again, suggesting improvements. Well worth the investment!"
+18
Serving Saint Charles, MO and surrounding areas
Approved
Super Service Award Winner
In business since 2017
Emergency services offered
Warranties offered
"Liberty did a fantastic job identifying and rectifying airflow problems with our existing Hvac system that was installed less than two years ago by another company. They were punctual, responsive and incredibly knowledgeable. I highly recommend them."
+10
Serving Saint Charles, MO and surrounding areas
Approved
In business since 2009
Warranties offered
Credit card accepted
"They were professional from the phone call to the installation. He had everything he needed to replace the hot water heater and proceeded. I would definitely recommend Hosack Plumbing."
+2
Serving Saint Charles, MO and surrounding areas
Approved
In business since 1995
Free estimates
Emergency services offered
"Seems I was spending a ridiculous amount of money on electricity because my central unit was not operating correctly. I now have flowing cold air."
Serving Saint Charles, MO and surrounding areas
Approved
In business since 2000
Emergency services offered
Credit card accepted
"Had new hvac, furnace, and hwh installed. Furnace had a couple of air leaks between a coil and furnace which I fixed myself. Hvac was spot on. Hwh failed first inspection, but was corrected in same day. For the premium price paid, these issues should not happen. Quality 4.5 because of these issues, same goes for value. Customer service is very good. They are very professional, work looks very good, clean worksite afterwards. I would recommend, but don't think about negotiating price with them. Their labor is very high."
+14
Serving Saint Charles, MO and surrounding areas
Approved
In business since 1980
Free estimates
Emergency services offered
"Job well done. Our Sub-Zero refrigerator was showing error messages and we called All American after reading reviews. We called on the weekend before Christmas and had an appointment on Tuesday. Jon - the tech - was great. He quickly ascertained the problem and explained it - coils in the back were leaking. Since parts had to be ordered, we had to wait the next week for the repair. We were nervous about getting through the Holiday, but Jon said he thought we would be fine. Thankfully, we made it through the Holiday and Jon returned to perform the repair. He was on time and once again took the time to explain things as needed. The process couldn't have gone smoother and we would recommend again.
"
Serving Saint Charles, MO and surrounding areas
Approved
In business since 1970
Warranties offered
Small jobs welcome
"I highly recommend AAA home services. They installed a brand new HVAC system and the entire process was trouble free every step of the way. I have had them out to service the system twice a year and the scheduling to do so is easy and the service has been excellent. AAA home services has always communicated well and I have had them do exceptional plumbing work including the installation of a hot water heater. Thank you AAA home services."
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