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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 RepairGas 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

8 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 - InstallCentral A/C - Service or RepairDuctless Mini-split A/C - Install or Replace+11 more

Serving O Fallon, MO and surrounding areas

Approved

In business since 2003

Free estimates

Emergency services offered

"Our tech Robert installed an intake pipe for our HVAC unit to the outside. Tech arrived and completed the work to specifications. We will continue to use Dunn for our HVAC needs going forward. Thank you!"
Additional Photos
Response time2 days
20 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(
513
)
Central A/C - InstallGas Furnace / Forced Air Heating System - InstallElectric 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 time1 day
Response rate86%
16 neighbors recently requested a quote
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Avatar for Liberty Heating & Cooling
Liberty Heating & Cooling
4.8(
46
)
Central A/C - InstallBoiler or Radiator Heating System - Install or ReplaceBoiler or Radiator Heating System - Install or Replace - For Business+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

6 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 - InstallBoiler or Radiator Heating System - Install or Replace+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 time6 days
10 neighbors recently requested a quote
Recommended by93%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
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 RepairAir Ducts & Vents - Clean+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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27 neighbors recently requested a quote
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Avatar for Wise Men Heating and Cooling, LLC
Wise Men Heating and Cooling, LLC
5.0(
7
)
Central A/C - InstallCentral A/C - Service or RepairCentral Air Cleaner - Repair or Service+22 more

Serving O Fallon, MO and surrounding areas

Approved

In business since 2000

Free estimates

Emergency services offered

"Had some filters updated. Glad to have a great HVAC guy!"
Full furnace
Full furnace
Full furnace
Heating Cooling HVAC
HVAC

+2

Response time7 hrs
Response rate100%
8 neighbors recently requested a quote
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Vintage Home Services
5.0(
15
)
Heat Pump - Repair or ServiceCentral A/C - Service or RepairElectric Furnace / Forced Air Heating System - Repair+7 more

Serving O Fallon, MO and surrounding areas

Approved

In business since 2018

Free estimates

Credit card accepted

"Adam did the work in my home today. There were three heating and air-conditioning units which were checked out and some which needed some repair. I highly recommend him. Reasonable cost excellent knowledge and willing to take the time to do an excellent job."
Response time1 day
5 neighbors recently requested a quote
Recommended by83%of homeowners
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Showing 1-10 of 374
Heating and Air Conditioning questions, answered by experts

If you know how to identify supply and return ducts, you’ll find that only the supply ducts will have dampers. Although your return ducts can have dampers, it’s not common. If you have one return duct that is pulling in too much air, adding a damper to it can help with overall system performance. However, dampers on return ducts are not a necessary addition for most homes.

The simplest indicator is how long it’s been since your last tune-up. You should schedule an annual AC tune-up each spring. Beyond that, there are multiple signs that your AC needs a quick check by a professional. These issues include higher-than-average energy bills, decreased air flow from vents, higher indoor temperatures, and an air conditioning unit that stays on all the time or frequently turns on and off.

Fixing a leak in an AC unit costs $200 to $1,600, depending on the type of leak and any related damage. But depending on the age and condition of your AC, it might make more sense to replace the AC unit instead of repairing it. If your AC is only a few years old and relatively problem-free, then repairing it is the right call. But if it’s nearing a decade old and has other issues, consider replacing it.

A home AC unit provides anywhere from one-half to five tons of cooling and requires approximately two to four pounds of refrigerant per ton of cooling. At approximately five to 10 minutes to fill one pound of refrigerant, a home that requires three tons of cooling will take about six to 12 pounds of refrigerant and approximately 30 minutes to two hours to completely recharge the unit.

The cost to replace an AC evaporator coil is typically between $600 and $2,500, with an average cost around $1,300 to $1,350. The price of the coil itself can range from $550 to $1,100, depending on the brand, size, and style, with professional labor adding around $700. Replacing a condenser coil is generally less expensive, costing about $800. Because this repair involves handling refrigerants, it requires a licensed AC professional. Regular inspections, which cost between $200 and $600, can help prevent costly coil replacements.

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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