293 HVAC contractors ranked by CR ScoreUpdated 0 paid placements in this rankingHow we rank →
Best overall in O'Fallon: Jerry Kelly Heating & Air Conditioning, CR Score 66/100; 4.9★ from 6,530 Google reviews; open 24/7.
Best for emergencies (open 24/7): Stay Cool Climate Control, posts 24/7 hours; ranked #2 of 293.
Most-reviewed: Hoffmann Brothers, 10,949 Google reviews at 4.9★, the most of 293 ranked; ranked #33.
Rankings can't be bought. Contractors can't pay to change their rank or score. How we rank
293 O'Fallon HVAC contractors are ranked here by CR Score, from ten published factors. 92 are open 24/7, 187 open Saturdays and 155 open Sundays, based on posted hours. The median Google rating is 4.9★ across 293 rated businesses.
| Rank | Business | CR Score | Google rating | Based in | Hours | Best for |
|---|---|---|---|---|---|---|
| 1 | Jerry Kelly Heating & Air Conditioning | 66 | 4.9★ (6,530) | Saint Peters, 7 mi away | 24/7 | Overall |
| 2 | Stay Cool Climate Control | 66 | 5.0★ (1,068) | O'Fallon | 24/7 | Emergencies |
| 3 | Hoock's Heating & Cooling | 65 | 5.0★ (768) | O'Fallon | 24/7 | — |
| 4 | Hosack Plumbing, Heating & Cooling | 65 | 5.0★ (696) | O'Fallon | 24/7 | — |
| 5 | Swiss, LLC | 65 | 4.9★ (924) | O'Fallon | 24/7 | — |
| 6 | Faszold Heating and Cooling | 65 | 4.9★ (873) | O'Fallon | 24/7 | — |
| 7 | Chesterfield Service | 64 | 4.9★ (4,286) | Chesterfield, 11 mi away | 24/7 | — |
| 8 | Air Comfort Service Inc. | 64 | 5.0★ (1,159) | Saint Peters, 7 mi away | 24/7 | — |
| 9 | Design Aire Heating and Cooling | 64 | 5.0★ (775) | O'Fallon | Sat · Sun · Evenings | — |
| 10 | B & B Heating & Cooling | 64 | 5.0★ (1,348) | Saint Charles, 10 mi away | 24/7 | — |
Ordered by CR Score, a 0–100 score from ten published factors. Paid placement never changes the order.
Scores below: based on 8 of 10 factors; credentials and recency not yet collected. Hatched segments mark factors we don't have yet.
Ranked #1 because of its Google rating and trade focus: 4.9★ from 6,530 Google reviews, listed on Google as “HVAC contractor”.
Based in O'Fallon
Ranked #2 because of its Google rating and trade focus: 5.0★ from 1,068 Google reviews, listed on Google as “HVAC contractor”.
Based in O'Fallon
Ranked #3 because of its Google rating and trade focus: 5.0★ from 768 Google reviews, listed on Google as “HVAC contractor”.
Based in O'Fallon
Ranked #4 because of its Google rating and trade focus: 5.0★ from 696 Google reviews, listed on Google as “HVAC contractor”.
Based in O'Fallon
Ranked #5 because of its Google rating and trade focus: 4.9★ from 924 Google reviews, listed on Google as “HVAC contractor”.
Based in O'Fallon
Ranked #6 because of its Google rating and trade focus: 4.9★ from 873 Google reviews, listed on Google as “HVAC contractor”.
Based in Chesterfield, 11 mi away
Ranked #7 because of its Google rating and trade focus: 4.9★ from 4,286 Google reviews, listed on Google as “HVAC contractor”.
Based in Saint Peters, 7 mi away
Ranked #8 because of its Google rating and trade focus: 5.0★ from 1,159 Google reviews, listed on Google as “HVAC contractor”.
Based in O'Fallon
Ranked #9 because of its Google rating and trade focus: 5.0★ from 775 Google reviews, listed on Google as “HVAC contractor”.
Based in Saint Charles, 10 mi away
Ranked #10 because of its Google rating and trade focus: 5.0★ from 1,348 Google reviews, listed on Google as “HVAC contractor”.
Based in O'Fallon
Ranked #11 because of its Google rating and trade focus: 4.9★ from 340 Google reviews, listed on Google as “HVAC contractor”.
Based in Dardenne Prairie, 6 mi away
Ranked #12 because of its Google rating and trade focus: 5.0★ from 2,219 Google reviews, listed on Google as “HVAC contractor”.
Based in St. Louis, 16 mi away
Ranked #13 because of its Google rating and trade focus: 4.9★ from 5,847 Google reviews, listed on Google as “HVAC contractor”.
Based in Hazelwood, 16 mi away
Ranked #14 because of its Google rating and trade focus: 4.8★ from 6,727 Google reviews, listed on Google as “Air conditioning contractor”.
Based in Saint Peters, 5 mi away
Ranked #15 because of its Google rating and trade focus: 5.0★ from 355 Google reviews, listed on Google as “HVAC contractor”.
Based in Saint Peters, 6 mi away
Ranked #16 because of its Google rating and trade focus: 4.8★ from 1,113 Google reviews, listed on Google as “HVAC contractor”.
Based in Wentzville, 8 mi away
Ranked #17 because of its Google rating and trade focus: 5.0★ from 609 Google reviews, listed on Google as “Air conditioning contractor”.
Based in Saint Peters, 4 mi away
Ranked #18 because of its Google rating and trade focus: 4.8★ from 6,200 Google reviews, listed on Google as “HVAC contractor”.
Based in Wentzville, 8 mi away
Ranked #19 because of its Google rating and trade focus: 5.0★ from 476 Google reviews, listed on Google as “HVAC contractor”.
Based in St. Louis, 19 mi away
Ranked #20 because of its Google rating and trade focus: 4.9★ from 4,820 Google reviews, listed on Google as “HVAC contractor”.
Based in Wentzville, 8 mi away
Ranked #21 because of its Google rating and trade focus: 5.0★ from 413 Google reviews, listed on Google as “Air conditioning contractor”.
Based in O'Fallon
Ranked #22 because of its Google rating and trade focus: 4.9★ from 1,490 Google reviews, listed on Google as “HVAC contractor”.
Based in Saint Peters, 4 mi away
Ranked #23 because of its Google rating and trade focus: 4.7★ from 2,039 Google reviews, listed on Google as “Air conditioning contractor”.
Based in Hazelwood, 17 mi away
Ranked #24 because of its Google rating and trade focus: 4.9★ from 2,041 Google reviews, listed on Google as “HVAC contractor”.
Based in Chesterfield, 10 mi away
Ranked #25 because of its Google rating and trade focus: 4.9★ from 1,784 Google reviews, listed on Google as “HVAC contractor”.
#1 to #25 are shown in full above. Here are #26 to #50, in CR Score order; each links to its profile. We publish the top 50 of 293 ranked HVAC contractors here; the rest are on their profiles.
| Rank | Business | CR Score | Google rating | Distance |
|---|---|---|---|---|
| 26 | Classic Aire Care | 62 | 5.0★ (1,014) | 16 mi |
| 27 | Reliable Heating & Cooling Inc. | 61 | 4.8★ (112) | In O'Fallon |
| 28 | Superior Service | 61 | 4.9★ (1,766) | 11 mi |
| 29 | Integrity Aire | 61 | 5.0★ (288) | 10 mi |
| 30 | Jerry Kelly Heating & Air Conditioning | 61 | 4.9★ (1,825) | 18 mi |
| 31 | Ozark Mechanical | 61 | 5.0★ (160) | 7 mi |
| 32 | Premier, Inc | 61 | 4.9★ (422) | 12 mi |
| 33 | Hoffmann Brothers | 61 | 4.9★ (10,949) | 23 mi |
| 34 | Air Alliance Team | 61 | 4.7★ (253) | 5 mi |
| 35 | Design Aire Heating and Cooling | 60 | 4.9★ (2,541) | 17 mi |
| 36 | Stevenson | 60 | 4.9★ (67) | 4 mi |
| 37 | Raydel Heating and Cooling | 60 | 5.0★ (101) | 8 mi |
| 38 | AAA Home Services | 60 | 4.7★ (834) | In O'Fallon |
| 39 | B & B Heating & Cooling | 60 | 4.9★ (1,285) | 21 mi |
| 40 | Missouri Furnace & Air Conditioning | 60 | 4.9★ (275) | 13 mi |
| 41 | Schraer Heating & Air Conditioning | 59 | 4.8★ (22) | In O'Fallon |
| 42 | Wentzville Air & Refrigeration | 59 | 5.0★ (15) | In O'Fallon |
| 43 | C-N-O Comfort Zone Heating & Cooling | 59 | 4.9★ (87) | 3 mi |
| 44 | Arch Air Services | 59 | 4.9★ (303) | 17 mi |
| 45 | Martin Jetco Heating & Air Conditioning | 59 | 4.9★ (1,177) | 24 mi |
| 46 | Autumn Air Company | 58 | 4.8★ (23) | 5 mi |
| 47 | SmartHouse Heating and Cooling | 58 | 4.9★ (476) | 23 mi |
| 48 | Wyzer Heating and Cooling 🔥❄️👨🔧 | 58 | 5.0★ (25) | 7 mi |
| 49 | O'Fallon Heating Air Conditioning | 58 | 4.8★ (26) | In O'Fallon |
| 50 | Brown's | 58 | 4.7★ (37) | In O'Fallon |
20 more HVAC contractors within 25 mi that we can't rank yet: too few reviews, or a trade we couldn't confirm. Listed A to Z.
| Business | Google rating | Distance |
|---|---|---|
| Atmosphere Air Care | 4.7★ (38) | In O'Fallon |
| Brentwood Heating, Cooling & Duct Cleaning | 5.0★ (2) | 11 mi |
| Expectancy Air Heating & Air Conditioning | 5.0★ (35) | 11 mi |
| Future Aire | 4.7★ (320) | 21 mi |
| Hazelwoods Heating and Air Conditioning | 5.0★ (2) | In O'Fallon |
| Hosack Plumbing, Heating & Cooling | 4.9★ (157) | 7 mi |
| iFOAM Insulation of O'Fallon | 5.0★ (113) | In O'Fallon |
| J&J Home Heating and Cooling | 5.0★ (2) | 9 mi |
| Jaxon Heating & Cooling | 5.0★ (2) | In O'Fallon |
| Legacy Plumbing | 5.0★ (1) | In O'Fallon |
| Merkel Mechanical Services | In O'Fallon | |
| Nation-Wide Refrigeration Inc | 5.0★ (2) | 10 mi |
| Optimal Heating and Cooling | 5.0★ (2) | 10 mi |
| Refrigeration & Kitchen Solutions Inc | 3.6★ (5) | In O'Fallon |
| River Valley Heating and Cooling | 5.0★ (31) | 10 mi |
| RK Heating & Cooling | In O'Fallon | |
| Saylors Systems Heating and AC Repair | 5.0★ (174) | 24 mi |
| Schraer Heating & Air Conditioning | 4.7★ (390) | 25 mi |
| Veterans HVAC | 5.0★ (2) | 5 mi |
| Welsch Heating & Cooling | 4.5★ (162) | 16 mi |
National price ranges in USD, not adjusted for O'Fallon. Each row names its basis and the month we checked it.
| Job | Low | Typical | High | Basis | Checked |
|---|---|---|---|---|---|
| AC replacement | $3,887 | $5,978 | $8,073 | Per system, installed (unit plus labor); typical range of customer-reported jobs. US national range | October 2026 |
| Furnace replacement | $2,823 | $4,814 | $6,896 | Per system, installed; typical range of customer-reported jobs. US national range | October 2026 |
HVAC demand peaks in summer for cooling and in winter for heating. Spring and fall are the easiest times to book maintenance or a replacement.
We scored 293 O'Fallon HVAC contractors on ten factors, weighted as shown. A business is ranked when its trade is confirmed and it has 3 or more Google reviews or a claimed profile. A business with no Google reviews scores zero on rating, review volume and recency. Other unknown factors are left out, not counted as zero. Scores last refreshed October 22, 2026.
Paid placement never changes a rank or score. Featured businesses are paid, labelled, limited to 3 and shown above the ranking, outside it.
| Factor | Weight | Computed from | In O'Fallon data |
|---|---|---|---|
| Reputation | 25% | Google star rating, adjusted for how many reviews back it | Measured |
| Credentials | 15% | Active state license, bond and workers’ comp on file | Not yet collected |
| Review volume | 10% | Number of Google reviews, compared with the most-reviewed business on the list | Measured |
| Recency | 5% | Share of reviews from the last 12 months | Not yet collected |
| Availability | 5% | Weekly open hours, Saturday, Sunday, 24/7 or same-day | Measured |
| Trade focus | 10% | How clearly the business does this trade (its Google category and name) | Measured |
| Proximity | 5% | Based in the city scores highest, less the farther away it is | Measured |
| Claimed profile | 10% | The business has claimed its ContractorsRanked profile (free or paid earn the same) | Measured |
| Partnered | 5% | The business links to ContractorsRanked from its own website with our badge, checked periodically | Measured |
| ContractorsRanked reviews | 10% | Verified customer reviews collected by ContractorsRanked: their rating and how many there are | Measured |