Top-rated heating and air conditioning pros.

Get matched with top heating and air conditioning pros in O Fallon, MO

Enter your zip and get matched with up to 5 pros

Need a pro for your heating and air conditioning service project in O Fallon, MO?

Select your specific project to find the pro for you.

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
)

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
Additional Photos
Additional Photos
Additional Photos
Additional Photos

+2

8 neighbors recently requested a quote
Recommended by92%of homeowners
Avatar for Dunn Heating Air Conditioning and Plumbing
Dunn Heating Air Conditioning and Plumbing
4.7(
273
)

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
Avatar for Anton's Plumbing, Heating/Cooling & Energy Experts
Anton's Plumbing, Heating/Cooling & Energy Experts
4.7(
513
)

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!"
Additional Photos
Additional Photos
Additional Photos
Additional Photos
Additional Photos

+18

Response time1 day
Response rate86%
16 neighbors recently requested a quote
Avatar for Liberty Heating & Cooling
Liberty Heating & Cooling
4.8(
46
)

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
Additional Photos
Additional Photos
Additional Photos
Additional Photos

+10

6 neighbors recently requested a quote
Recommended by93%of homeowners
Avatar for Hosack Plumbing Heating & Cooling
Hosack Plumbing Heating & Cooling
4.8(
344
)

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."
.
.
.
.
.

+2

Response time6 days
10 neighbors recently requested a quote
Recommended by93%of homeowners
Avatar for AAA Home Services
AAA Home Services
4.9(
9
)

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
Avatar for Anton's Plumbing, Heating/Cooling Energy Experts
Anton's Plumbing, Heating/Cooling Energy Experts
4.6(
81
)

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
Avatar for Aire Serv of St. Louis
Aire Serv of St. Louis
5.0(
5
)

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!

Logo
27 neighbors recently requested a quote
...
Showing 1-10 of 374
Heating and Air Conditioning questions, answered by experts

The compressor is the heart of your AC system and is one of the most important parts required to keep it functioning properly. If your AC unit is making a popping, banging, clanging, clicking, or screeching sound, it could point to a problem with the compressor. If the unit is physically vibrating, that can also be an indication that your AC compressor is going bad.

Your heating and cooling systems cost you the most on your electric bill and make up 50% of your bill on average. Your washing machine, dryer, oven, and stove contribute significantly to your electric bill as well. Lights, fans, and smaller electronics add up, but aren’t the biggest energy consumers. You can reduce your power usage by setting optimal temperatures on your thermostat and investing in energy-efficient appliances.

The American Society of Heating, Refrigerating, and Air-Conditioning Engineers, or ASHRAE, sets the standard guidelines for air changes per hour in homes and businesses. The International Residential Code, or IRC, also sets ACH requirements for residences and bases those requirements off of ASHRAE standards plus climate specifics related to your location.

Unfreezing an AC unit is not a DIY project unless the problem is a dirty air filter. Changing out an air filter is easy for homeowners, but otherwise, trying to repair ductwork, refill refrigerant, or replace a blower fan motor are tasks best left to the pros. Otherwise, you could cause further damage to your cooling system or even harm to yourself.

During the summer, it’s best to set your AC to 78 degrees when you’re home and awake, according to the Department of Energy (DOE). For better energy efficiency, raise the temperature slightly to 85 degrees while you’re out of the house. The National Sleep Foundation advises lowering your thermostat to between 60 and 67 degrees when you’re asleep.

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.