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TRUSTED BY O FALLON, MO HOMEOWNERS

  • Average homeowner rating star icon4.7
    Average homeowner rating
  • Verified reviews icon1.2k+
    Verified heating and air conditioning services reviews

Verified Reviews for Heating And Air Conditioning Service pros in O Fallon, MO

*The Angi rating for Heating And Air Conditioning Service companies in O Fallon, 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 O Fallon, 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 January 07, 2026

Find Heating and air conditioning pros in O Fallon

Avatar for Fresh Air Heating & Cooling
Fresh Air Heating & Cooling
4.8(
277
)
Central A/C - InstallCentral A/C - Service or RepairElectric Furnace / Forced Air Heating System - Install+47 more

Serving O Fallon, MO and surrounding areas

Approved

In business since 1947

Free estimates

Emergency services offered

"Great Experience. I was concerned about the 22 yr age of our air conditioner able to keep working and wonder if a long wait time to get a product shipped like refrigerators last year, I called for a quote and within a week it was installed and working! Installers worked tirelessly until their work was done, clean and neat!"
Fresh Air Van
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+2

12 neighbors recently requested a quote
Recommended by92%of homeowners
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Avatar for Dunn Heating Air Conditioning and Plumbing
Dunn Heating Air Conditioning and Plumbing
4.7(
273
)
Central A/C - InstallElectric Furnace / Forced Air Heating System - InstallCentral A/C - Service or Repair+11 more

Serving O Fallon, MO and surrounding areas

Approved

In business since 2003

Free estimates

Emergency services offered

"A-ok! Dunn OneHour HVAC is always top notch!"
Additional Photos
Response time2 days
27 neighbors recently requested a quote
Recommended by90%of homeowners
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Avatar for Anton's Plumbing, Heating/Cooling & Energy Experts
Anton's Plumbing, Heating/Cooling & Energy Experts
4.7(
515
)
Central A/C - InstallElectric Furnace / Forced Air Heating System - InstallGas Furnace / Forced Air Heating System - Install+38 more

Serving O Fallon, MO and surrounding areas

Approved (Corporate)

Super Service Award Winner

In business since 1979

Free estimates

Emergency services offered

"I always recommend Anton's to family and friends who need HVAC services. Their prices are reasonable, and their service is top notch! All of their technicians are very professional and considerate and they don't try to sell you things you don't need. Ronan just came out this morning to do our annual A/C inspection. The service was excellent as always. He took the time to explain everything and made recommendations. I never felt pressured, and I trust this company to take care of my HVAC needs. They've got a customer for life!"
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+18

Response time12 hrs
Response rate100%
19 neighbors recently requested a quote
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Avatar for Liberty Heating & Cooling
Liberty Heating & Cooling
4.8(
46
)
Central A/C - InstallCentral A/C - Service or RepairBoiler or Radiator Heating System - Install or Replace+25 more

Serving O Fallon, 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."
A/C replacement
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+10

5 neighbors recently requested a quote
Recommended by93%of homeowners
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Avatar for Hosack Plumbing Heating & Cooling
Hosack Plumbing Heating & Cooling
4.8(
344
)
Central A/C - InstallGas Furnace / Forced Air Heating System - InstallCentral A/C - Service or Repair+47 more

Serving O Fallon, MO and surrounding areas

Approved

In business since 2009

Warranties offered

Credit card accepted

"Awesom. Highly recommend Glen. We bought new refrigerator and needed new updated waterline installed. Since we had plumber in house wanted to update things we knew we needed done eventually."
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+2

Response time8 hrs
8 neighbors recently requested a quote
Recommended by93%of homeowners
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Avatar for American Society of Heating & Cooling Specialists LLC
American Society of Heating & Cooling Specialists LLC
4.4(
17
)
Central A/C - Service or RepairCentral Air Cleaner - Repair or ServiceDucts & Vents - Install or Replace+9 more

Serving O Fallon, 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."
DOLLAR TREE COMMODE
DOLLAR TREE
DOLOLAR TREE
Patriot Club Member
Patriot Club Member

+9

1 neighbors recently requested a quote
Recommended by47%of homeowners
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Avatar for All American Appliance Service Inc
All American Appliance Service Inc
4.5(
528
)
Central A/C - Service or RepairThermostat - Repair or Reprogram

Serving O Fallon, MO and surrounding areas

Approved

In business since 1980

Free estimates

Emergency services offered

"Great! Professional, on time , left area clean. Gave us an estimate on our washing machine repair and plan to follow up with this service. I would highly recommend this company. I was called by this company and they sent out a repairman from All Type Appliance Repair. I would highly recommend them!"
Additional Photos
Response time2 days
5 neighbors recently requested a quote
Recommended by89%of homeowners
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Avatar for AAA Home Services
AAA Home Services
4.9(
9
)
Central A/C - Service or Repair

Serving O Fallon, 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."
AC units from American Standard
HVAC Installation
HVAC Installation
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Avatar for Anton's Plumbing, Heating/Cooling Energy Experts
Anton's Plumbing, Heating/Cooling Energy Experts
4.6(
81
)
Central A/C - InstallCentral A/C - Service or RepairElectric Furnace / Forced Air Heating System - Install+8 more

Serving O Fallon, MO and surrounding areas

Approved

In business since 2000

Free estimates

Emergency services offered

"Both the estimator Kevin the two installers who visited my home were very professional and kind. They answered all my questions and provided a very reasonable price for the installation of the attic insulation. I feel I was very informed on the federal rebate that was available for this installation, as well as on the recommendations of quantity of insulation I needed per residential standards and codes. I would recommend Anton and will use them in the future for my HVAC needs!"
Response time6 hrs
1 neighbors recently requested a quote
Recommended by95%of homeowners
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Avatar for Aire Serv of St. Louis
Aire Serv of St. Louis
5.0(
5
)
Central A/C - InstallCentral A/C - Service or RepairGas Furnace / Forced Air Heating System - Install+11 more

Serving O Fallon, MO and surrounding areas

Approved

In business since 2024

Free estimates

Emergency services offered

Looking for reliable HVAC service in St. Louis? Aire Serv of St. Louis is your local expert for residential and commercial heating and cooling. From emergency AC repair during humid Missouri summers to furnace maintenance before the winter chill, our professional technicians are available to keep your home comfortable. We pride ourselves on transparent, upfront pricing, no overtime charges, and the "Done Right Promise." Whether you need a system replacement, duct cleaning, or a routine tune-up in Fenton, Webster Groves, or Kirkwood, we are the team you can trust. Breathe easy with Aire Serv—your comfort is our top priority. Call us today to schedule your service!

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16 neighbors recently requested a quote
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Heating and Air Conditioning questions, answered by experts

It’s normal to hear a low humming sound as air moves through your vents. Most of the time, you probably won’t even notice it. However, if that sound becomes disruptive or if you hear more concerning noises (such as rattling, clicking, banging, hissing, or grinding), there might be a problem with your HVAC system.

Yes, HVAC zoning is generally considered worth the investment by both experts and homeowners. Zoned systems offer significant benefits in convenience, efficiency, and comfort by allowing you to set different temperatures for various rooms or 'zones' in your house. This ability to heat and cool only the spaces you're using leads to energy savings and lower utility bills. Zoned systems are especially effective in multi-level homes that experience temperature fluctuations, but even smaller homes can benefit from the ability to adjust temperatures more quickly. While the up-front installation cost can be high, many find it's a worthwhile long-term investment, particularly for those who plan to stay in their home for a while.

Yes, a dehumidifier and air conditioner can be used simultaneously in a home. A dehumidifier can bolster an air conditioner’s efficiency. Typically, a dehumidifier is used when the air conditioner alone cannot keep a home’s humidity levels at a comfortable indoor humidity level, which should, ideally, be between 30% and 50%.

If you’re shopping around for a rooftop AC unit, you may hear them referred to as “package units.” That’s because rooftop AC systems are all-in-one heating and cooling units that connect directly to your home’s ductwork. If your AC repair pro references a package unit, they are referring to the system on your roof.

While it is possible to add Freon to your AC unit yourself, it is not recommended. In fact, the U.S. Environmental Protection Agency (EPA) prohibits the handling of Freon without a license. Freon is a dangerous gas that can cause irreversible damage to your AC or yourself if not installed correctly. It is worthwhile to hire a professional to add Freon to your AC.

The O Fallon, MO homeowners’ guide to heating and air conditioning services

From average costs to expert advice, get all the answers you need to get your job done.

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