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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

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
Avatar for Anton's Plumbing, Heating/Cooling & Energy Experts
Anton's Plumbing, Heating/Cooling & Energy Experts
4.7(
516
)
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%
18 neighbors recently requested a quote
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

4 neighbors recently requested a quote
Recommended by93%of homeowners
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
7 neighbors recently requested a quote
Recommended by89%of homeowners
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
1 neighbors recently requested a quote
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
2 neighbors recently requested a quote
Recommended by95%of homeowners
Avatar for Aire Serv of St. Louis
Aire Serv of St. Louis
5.0(
5
)
Central A/C - InstallGas Furnace / Forced Air Heating System - InstallAir 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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22 neighbors recently requested a quote
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Heating and Air Conditioning questions, answered by experts

The standard rule for return duct sizing is that the return vent should be the same size or larger than the supply vent. This will ensure balanced airflow in your home and reduce strain on your HVAC system.

You can protect your air conditioner in the winter by turning off the power at the thermostat and performing routine HVAC maintenance in the spring. Regular maintenance, cleaning, and repair of your AC unit helps protect it and extend its life span. If you have a window AC unit, remove it from the window and store it in a dry place during the winter. Window units cannot withstand freezing temperatures. Keeping them in your window also allows cold air to seep into your home.

Yes, technicians check refrigerant levels, loop performance, and system calibration for peak efficiency.

Most units are designed only to cool the house down to 20 degrees less than the temperature outside. This means that if it’s 99 degrees Fahrenheit out and you’re trying to cool your home down to 65 degrees, you’ll notice your AC is struggling. 

Lower the blinds on all your windows, turn on your ceiling fans, and keep the thermostat at a consistent temperature to help your AC do its job. Investing in an HVAC maintenance plan also helps because pros will come out to inspect and tune up your unit regularly, keeping it in optimal working condition.

The best time of year to purchase or replace an HVAC system, including components like an air conditioner or furnace, is during the off-season—spring and fall. During these periods, HVAC professionals are less busy than in summer and winter, when extreme temperatures create urgent demand. Shopping during the off-season can lead to savings of 10% to 15% on an AC unit and allows you more time to find the best deal and other cost-saving incentives. Typically, air conditioning units go on sale in the fall after demand drops, while furnace prices tend to decrease in the spring.

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.