4.7 
81 *The Angi rating for Heating And Air Conditioning Service companies in Herculaneum, 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 Herculaneum, 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 July 19, 2026
Serving Herculaneum, MO and surrounding areas
Approved
In business since 2003
Free estimates
Emergency services offered
"A-ok! Dunn OneHour HVAC is always top notch!"
Serving Herculaneum, MO and surrounding areas
Approved
Super Service Award Winner
In business since 2017
Emergency services offered
Warranties offered
"Installed a new gas water heater. Was very knowledgeable and got it done. Great job, thank you Sam."
+10
Serving Herculaneum, MO and surrounding areas
Approved
In business since 2014
Free estimates
Emergency services offered
"MCS techs were very courteous. New HVAC system install went well. They explained all their work professionally. Also found a crack in the flue and replaced which was overlooked by a previous contractor. They are very thorough and reasonable. I highly recommend MCS."
Serving Herculaneum, MO and surrounding areas
Approved
In business since 1954
Free estimates
Emergency services offered
"I’ve used this company twice. My husband has a medical condition that is affected by heat. The first time the air conditioner wasn’t working they made every effort to assess the problem immediately when I explained the medical condition. At the time they corrected the problem I was advised the system was probably 20 years old and we may have to consider a new system soon. The second time I contacted Comfortable Carla’s was about 4-6 weeks later when the system wasn’t working again. This lead to a system replacement. I was provided with different options, my questions were answered and the installation was completed as quickly as possible, especially in view of my husband’s medical issue. The staff was was professional, efficient and kept me apprised all throughout the process. I highly recommend this company."
+1
Serving Herculaneum, MO and surrounding areas
Approved
In business since 2006
Free estimates
Credit card accepted
"Great guy and good service had me fixed up went out of his way to get ac going."
Serving Herculaneum, MO and surrounding areas
Approved
In business since 1980
Free estimates
Emergency services offered
"The service tech was prompt, friendly, and helpful. They identified the issue with two fridges, and they recommended replacement or adjustment rather than costly unnecessary repairs."
Serving Herculaneum, MO and surrounding areas
Approved
In business since 1982
Emergency services offered
Warranties offered
Founded in 1982. Team members that are drug tested and background checked insuring that the people in your home are safe. We specialize in repairing and replacing residential heating and air conditioning systems. "Fixed Right or It's Free"\nTechs available Sat & Sun call for appointment.
Serving Herculaneum, MO and surrounding areas
Approved
In business since 2025
Emergency services offered
Credit card accepted
"Had a few issues with my HVAC. Austin was fantastic and fixed everything the same time. Was late"
Serving Herculaneum, MO and surrounding areas
Approved
In business since 2025
Free estimates
Emergency services offered
"They did a fabulous job in cleaning all the vents in the house. The entire crew was very professional and treated our home with care. Even our dog loved them! We highly recommend using them!"
+21
Serving Herculaneum, MO and surrounding areas
Approved
In business since 2003
Free estimates
Emergency services offered
"We had our HVAC duct work cleaned as well as the dryer vent. Obviously, it is kind of hard to tell how good the job was done, since it is all enclosed. However, we feel from talking with the technician & seeing what did come out, they did a good job. Also, they were very reasonable for the service. Bob, the owner, explained everything regarding the service very well. They were on time, actually a little early. They were very efficient in getting the job done. Will use them again, maybe this time for carpet cleaning. We also try to use locally owned small businesses, compared to the large companies."
+6
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