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Find Air conditioning pros in Saint Charles

Avatar for Fresh Air Heating & Cooling
Fresh Air Heating & Cooling
4.8(
277
)
Central A/C - InstallCentral A/C - Service or RepairCentral A/C - Install - For Business+12 more

Serving Saint Charles, 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

12 neighbors recently requested a quote
Recommended by92%of homeowners
Avatar for SmartHouse Heating & Cooling
SmartHouse Heating & Cooling
4.7(
593
)
Central A/C - InstallCentral A/C - Install - For BusinessCentral A/C - Service or Repair+12 more

Serving Saint Charles, MO and surrounding areas

Approved

In business since 1947

Free estimates

Emergency services offered

"Technician Bob Going was on time, very proficient and professional. Over the years I've used several different companies for AC clean and checks. Bob did the most thorough cleaning of the outside unit ever. He shared his recommendation on how expensive of a furnace filter is really needed and gave me other tips on HVAC operations. I will definitely use SmartHouse again and request Bob. I plan to enroll in one of their maintenance agreements for easier, continuous care of my HVAC system."
Old boiler being removed
A Manual-J load calculation is performed to determine the precise amount of heating and cooling needed for each space.
Installing a Mitsubishi Hyper Heat Mini Split System to Heat and Cool this Sunroom Addition.
Mitsubishi outdoor unit installed on rooftop to heat and cool 3rd floor of this St. Louis City home.
Daikin FIT Heat Pump Installed in University City Home

+106

Response time2 days
3 neighbors recently requested a quote
Recommended by91%of homeowners
Avatar for Liberty Heating & Cooling
Liberty Heating & Cooling
4.8(
46
)
Central A/C - InstallCentral A/C - Service or RepairCentral A/C - Install - For Business+3 more

Serving Saint Charles, MO and surrounding areas

Approved

Super Service Award Winner

In business since 2017

Emergency services offered

Warranties offered

"I called, not knowing what was wrong with my air conditioning. They actually gave me a few possibilities, over the phone, one of which turned out to be the Culprit. No charge for the advice, they could have easily rip me off. But didn't. They won't give u the run around, and tell you somethings wrong when it's actually not."
A/C replacement
Additional Photos
Additional Photos
Additional Photos
Additional Photos

+10

4 neighbors recently requested a quote
Recommended by93%of homeowners
Avatar for Hosack Plumbing Heating & Cooling
Hosack Plumbing Heating & Cooling
4.8(
344
)
Central A/C - InstallCentral A/C - Service or RepairCentral A/C - Install - For Business+12 more

Serving Saint Charles, MO and surrounding areas

Approved

In business since 2009

Warranties offered

Credit card accepted

"Mike was awesome, very knowledgeable and friendly. Efficiently got the furnace running as it should be! Even took the time to educate me on what the issue was and explained what he did to fix it. Highly recommend!"
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+2

Response time8 hrs
13 neighbors recently requested a quote
Recommended by93%of homeowners
Avatar for Hoffmann Brothers
Hoffmann Brothers
4.5(
43
)
Central A/C - Service or RepairCentral A/C - InstallCentral A/C - Install - For Business+4 more

Serving Saint Charles, MO and surrounding areas

Approved

In business since 2000

Emergency services offered

Credit card accepted

"Had new hvac, furnace, and hwh installed. Furnace had a couple of air leaks between a coil and furnace which I fixed myself. Hvac was spot on. Hwh failed first inspection, but was corrected in same day. For the premium price paid, these issues should not happen. Quality 4.5 because of these issues, same goes for value. Customer service is very good. They are very professional, work looks very good, clean worksite afterwards. I would recommend, but don't think about negotiating price with them. Their labor is very high."
Installation
Installation
Heat Pump
Heat Pump
Furnace

+14

1 neighbors recently requested a quote
Recommended by97%of homeowners
Avatar for Hively Home Comfort LLC
Hively Home Comfort LLC
4.8(
47
)
Central A/C - Service or RepairCentral Humidifier - Repair or Service

Serving Saint Charles, MO and surrounding areas

Approved

In business since 2017

Free estimates

Credit card accepted

We take great pride in our experience, expertise, quality, and customer service that we provide to meet the consumer's needs. It is our mission to provide excellent workmanship and complete customer satisfaction from start to completion of a project. In order to understand the needs and expectations of our customers, we take great care to work and communicate with every customer in a professional manner. Our reputation is based on service, safety, and quality, regardless of how large or small the job.

1 neighbors recently requested a quote
Recommended by65%of homeowners
Avatar for Aire Serv of St. Louis
Aire Serv of St. Louis
5.0(
5
)
Central A/C - InstallCentral A/C - Service or RepairCentral Air Cleaner - Install or Replace+4 more

Serving Saint Charles, 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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19 neighbors recently requested a quote
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FAQs for air conditioning projects in Saint Charles, MO

Most professional HVAC technicians require two to three hours to complete an expansion valve replacement. The timeframe depends on your unit's accessibility and whether additional repairs are needed. The process involves recovering refrigerant, removing the old valve, installing the new component, and recharging the system. Scheduling during less busy seasons may result in more convenient appointment times.

Operating your air conditioner with a malfunctioning expansion valve isn't advisable. Continuing to run the system could potentially damage other components, particularly your compressor, which is significantly more expensive to replace. If you notice performance issues like inconsistent cooling or unusual noises, it's best to have your system inspected before continuing regular use.

Expansion valves don't have a standard replacement schedule, as their longevity depends on system usage, maintenance frequency, and environmental factors. Regular professional maintenance helps identify potential valve issues before they cause system failure. Having your HVAC system serviced annually allows technicians to monitor component condition and recommend preventative replacements when necessary.

Refrigerant leaks require prompt professional attention. If your expansion valve is leaking, you'll likely notice reduced cooling performance and possibly hear hissing sounds near the unit. Addressing leaks quickly prevents further system inefficiency and avoids the environmental impact of released refrigerant. Your HVAC technician will need to repair the leak and recharge the system with the proper refrigerant type and amount.

Because many AC issues present similar symptoms, professional diagnosis is recommended. Problems like inadequate cooling, inconsistent temperatures, or strange noises could indicate expansion valve issues, but might also stem from refrigerant leaks, electrical problems, or airflow restrictions. A qualified HVAC technician has the tools and expertise to accurately identify the root cause and recommend appropriate repairs.

The Saint Charles, MO homeowners’ guide to air conditioning services

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