248 HVAC contractors ranked by CR ScoreUpdated 0 paid placements in this rankingHow we rank →
Best overall in O'Fallon: Morrison Plumbing, Heating, Air, & Electrical Services, CR Score 94/100; 4.9★ from 8,631 Google reviews; open 24/7.
Best for emergencies (open 24/7): Classic Aire Care, posts 24/7 hours; ranked #2 of 248.
Most-reviewed: Hoffmann Brothers, 10,949 Google reviews at 4.9★, the most of 248 ranked; ranked #15.
Rankings can't be bought. Contractors can't pay to change their rank or score. How we rank
248 O'Fallon HVAC contractors are ranked here by CR Score, from 8 published factors. 77 are open 24/7, 151 open Saturdays and 127 open Sundays, based on posted hours. The median Google rating is 4.9★ across 248 rated businesses.
| Rank | Business | CR Score | Google rating | Based in | Hours | Best for |
|---|---|---|---|---|---|---|
| 1 | Morrison Plumbing, Heating, Air, & Electrical Services | 94 | 4.9★ (8,631) | Collinsville, 9 mi away | 24/7 | Overall |
| 2 | Classic Aire Care | 93 | 5.0★ (1,160) | Fairview Heights, 4 mi away | 24/7 | Emergencies |
| 3 | Home Heating & Cooling | 93 | 5.0★ (586) | O'Fallon | 24/7 | — |
| 4 | Hoffmann Brothers | 92 | 4.9★ (5,405) | Edwardsville, 15 mi away | 24/7 | — |
| 5 | Tiger Plumbing, Heating, Air Conditioning, & Electrical Services | 91 | 4.7★ (5,072) | Collinsville, 8 mi away | 24/7 | — |
| 6 | BELOMAN | 91 | 4.9★ (1,500) | Belleville, 8 mi away | 24/7 | — |
| 7 | Viviano Heating & Air Conditioning, Inc. | 91 | 4.9★ (890) | Collinsville, 7 mi away | 24/7 | — |
| 8 | Polar Plumbing, Heating & Air Conditioning | 91 | 5.0★ (514) | Collinsville, 8 mi away | 24/7 | — |
| 9 | Classic Aire Care | 91 | 5.0★ (1,039) | Edwardsville, 13 mi away | 24/7 | — |
| 10 | Heritage Heating & Cooling | 90 | 5.0★ (581) | O'Fallon | Sat · Sun · Evenings | — |
Ordered by CR Score, a 0–100 score from 8 published factors. Paid placement never changes the order.
Scores below: based on 6 of 8 factors; credentials and recency not yet collected. Hatched segments mark factors we don't have yet.
Ranked #1 in O'Fallon
Based in Collinsville, 9 mi away
Ranked #1 because of its Google rating and availability: 4.9★ from 8,631 Google reviews, open 24/7.
Based in Fairview Heights, 4 mi away
Ranked #2 because of its Google rating and availability: 5.0★ from 1,160 Google reviews, open 24/7.
Based in O'Fallon
Ranked #3 because of its Google rating and availability: 5.0★ from 586 Google reviews, open 24/7.
Based in Edwardsville, 15 mi away
Ranked #4 because of its Google rating and availability: 4.9★ from 5,405 Google reviews, open 24/7.
Based in Collinsville, 8 mi away
Ranked #5 because of its Google rating and availability: 4.7★ from 5,072 Google reviews, open 24/7.
Based in Belleville, 8 mi away
Ranked #6 because of its Google rating and availability: 4.9★ from 1,500 Google reviews, open 24/7.
Based in Collinsville, 7 mi away
Ranked #7 because of its Google rating and availability: 4.9★ from 890 Google reviews, open 24/7.
Based in Collinsville, 8 mi away
Ranked #8 because of its Google rating and availability: 5.0★ from 514 Google reviews, open 24/7.
Based in Edwardsville, 13 mi away
Ranked #9 because of its Google rating and availability: 5.0★ from 1,039 Google reviews, open 24/7.
Based in O'Fallon
Ranked #10 because of its Google rating and trade focus: 5.0★ from 581 Google reviews, listed on Google as “HVAC contractor”.
Based in St. Louis, 16 mi away
Ranked #11 because of its Google rating and availability: 4.9★ from 1,401 Google reviews, open 24/7.
Based in East Saint Louis, 8 mi away
Ranked #12 because of its Google rating and availability: 5.0★ from 123 Google reviews, open 24/7.
Based in St. Louis, 23 mi away
Ranked #13 because of its Google rating and availability: 5.0★ from 1,430 Google reviews, open 24/7.
Based in Mascoutah, 10 mi away
Ranked #14 because of its Google rating and availability: 4.9★ from 169 Google reviews, open 24/7.
Based in Brentwood, 23 mi away
Ranked #15 because of its Google rating and review volume: 4.9★ from 10,949 Google reviews, the most Google reviews on this list (10,949).
Based in Edwardsville, 9 mi away
Ranked #16 because of its Google rating and availability: 4.9★ from 82 Google reviews, open 24/7.
Based in St. Louis, 19 mi away
Ranked #17 because of its Google rating and availability: 4.9★ from 494 Google reviews, open 24/7.
Based in St. Louis, 20 mi away
Ranked #18 because of its Google rating and availability: 4.9★ from 487 Google reviews, open 24/7.
Based in Shiloh, 7 mi away
Ranked #19 because of its Google rating and availability: 4.9★ from 36 Google reviews, open 24/7.
Based in Collinsville, 9 mi away
Ranked #20 because of its Google rating and availability: 5.0★ from 38 Google reviews, open 24/7.
Based in Belleville, 7 mi away
Ranked #21 because of its Google rating and trade focus: 4.9★ from 318 Google reviews, listed on Google as “HVAC contractor”.
Based in Belleville, 5 mi away
Ranked #22 because of its Google rating and availability: 5.0★ from 197 Google reviews, open 24/7.
Based in St. Louis, 22 mi away
Ranked #23 because of its Google rating and availability: 4.9★ from 476 Google reviews, open 24/7.
Based in East Saint Louis, 4 mi away
Ranked #24 because of its Google rating and availability: 4.9★ from 40 Google reviews, open 24/7.
Based in Belleville, 7 mi away
Ranked #25 because of its Google rating and trade focus: 4.9★ from 230 Google reviews, listed on Google as “HVAC contractor”.
#1 to #25 are shown in full above. Here are #26 to #31, in CR Score order; each links to its profile. We publish the top 31 of 248 ranked HVAC contractors here; the rest are on their profiles.
| Rank | Business | CR Score | Google rating | Distance |
|---|---|---|---|---|
| 26 | Jersey heating and cooling llc | 85 | 5.0★ (163) | 21 mi |
| 27 | B & W Heating & Cooling | 85 | 4.8★ (383) | 21 mi |
| 29 | CLEANSTREAM LLC | 85 | 5.0★ (202) | In O'Fallon |
| 31 | Belleville Services | 84 | 4.7★ (49) | 7 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 |
In Illinois, furnace and heat pump calls peak in the coldest winter weeks and AC calls in summer heat waves. Spring and fall are the easiest times to book maintenance or a replacement.
We scored 248 O'Fallon HVAC contractors on 8 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. Unknown factors are left out of the score, 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 | 35% | Bayesian-adjusted Google star rating | Measured |
| Credentials | 15% | Active state license 0.6, bond 0.2, workers’ comp 0.2 | Not yet collected |
| Review volume | 10% | log10(reviews + 1) against the list maximum | Measured |
| Recency | 10% | Share of reviews from the last 12 months | Not yet collected |
| Availability | 10% | Weekly open hours, Saturday, Sunday, 24/7 or same-day | Measured |
| Trade focus | 10% | Google main category 1.0, business name 0.7, additional category 0.5 | Measured |
| Proximity | 5% | 1.0 when based in the city, falling to 0 at the trade’s radius | Measured |
| Completeness | 5% | Website, photos, description, hours, claimed profile (0.2 each) | Measured |