559 HVAC contractors ranked by CR ScoreUpdated 0 paid placements in this rankingHow we rank →
Best overall in St. Charles: A-Plus Service Experts, CR Score 64/100; 4.8★ from 1,234 Google reviews; open 24/7.
Best for emergencies (open 24/7): Mission Comfort, posts 24/7 hours; ranked #2 of 559.
Most-reviewed: Michael & Son Services, 15,537 Google reviews at 4.7★, the most of 559 ranked; ranked #6.
Rankings can't be bought. Contractors can't pay to change their rank or score. How we rank
559 St. Charles HVAC contractors are ranked here by CR Score, from ten published factors. 182 are open 24/7, 383 open Saturdays and 259 open Sundays, based on posted hours. The median Google rating is 4.9★ across 559 rated businesses.
| Rank | Business | CR Score | Google rating | Based in | Hours | Best for |
|---|---|---|---|---|---|---|
| 1 | A-Plus Service Experts | 64 | 4.8★ (1,234) | St. Charles | 24/7 | Overall |
| 2 | Mission Comfort | 64 | 5.0★ (625) | Waldorf, 1 mi away | 24/7 | Emergencies |
| 3 | Olympic Aire Services Inc | 63 | 4.9★ (426) | Accokeek, 2 mi away | 24/7 | — |
| 4 | United Air Temp | 63 | 4.7★ (855) | Waldorf, 1 mi away | 24/7 | — |
| 5 | GW Air Service | 63 | 4.9★ (270) | St. Charles | 24/7 | — |
| 6 | Michael & Son Services | 62 | 4.7★ (15,537) | Alexandria, 19 mi away | 24/7 | Most reviews |
| 7 | John C. Flood | 62 | 4.8★ (4,976) | Alexandria, 18 mi away | 24/7 | — |
| 8 | F.H. Furr Plumbing, Heating, Air Conditioning & Electrical | 61 | 4.7★ (4,469) | Lorton, 17 mi away | 24/7 | — |
| 9 | Fixed Right & Guaranteed Super Techs, LLC | 61 | 5.0★ (1,032) | Rosaryville, 17 mi away | 24/7 | — |
| 10 | United Air Temp | 61 | 4.8★ (1,775) | Fort Washington, 14 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: 4.8★ from 1,234 Google reviews, listed on Google as “HVAC contractor”.
Based in Waldorf, 1 mi away
Ranked #2 because of its Google rating and trade focus: 5.0★ from 625 Google reviews, listed on Google as “HVAC contractor”.
Based in Accokeek, 2 mi away
Ranked #3 because of its Google rating and trade focus: 4.9★ from 426 Google reviews, listed on Google as “Air conditioning contractor”.
Based in Waldorf, 1 mi away
Ranked #4 because of its Google rating and trade focus: 4.7★ from 855 Google reviews, listed on Google as “HVAC contractor”.
Based in St. Charles
Ranked #5 because of its Google rating and trade focus: 4.9★ from 270 Google reviews, listed on Google as “HVAC contractor”.
Based in Alexandria, 19 mi away
Ranked #6 because of its Google rating and review volume: 4.7★ from 15,537 Google reviews, the most in St. Charles.
Based in Alexandria, 18 mi away
Ranked #7 because of its Google rating and trade focus: 4.8★ from 4,976 Google reviews, listed on Google as “HVAC contractor”.
Based in Lorton, 17 mi away
Ranked #8 because of its Google rating and trade focus: 4.7★ from 4,469 Google reviews, listed on Google as “HVAC contractor”.
Based in Rosaryville, 17 mi away
Ranked #9 because of its Google rating and trade focus: 5.0★ from 1,032 Google reviews, listed on Google as “HVAC contractor”.
Based in Fort Washington, 14 mi away
Ranked #10 because of its Google rating and trade focus: 4.8★ from 1,775 Google reviews, listed on Google as “HVAC contractor”.
Based in Waldorf, 1 mi away
Ranked #11 because of its Google rating and trade focus: 4.9★ from 92 Google reviews, listed on Google as “HVAC contractor”.
Based in Alexandria, 18 mi away
Ranked #12 because of its Google rating and trade focus: 4.9★ from 1,631 Google reviews, listed on Google as “HVAC contractor”.
Based in St. Charles
Ranked #13 because of its Google rating and trade focus: 4.9★ from 67 Google reviews, listed on Google as “HVAC contractor”.
Based in Dale City, 18 mi away
Ranked #14 because of its Google rating and trade focus: 4.8★ from 2,138 Google reviews, listed on Google as “Air conditioning contractor”.
Based in Alexandria, 19 mi away
Ranked #15 because of its Google rating and trade focus: 5.0★ from 959 Google reviews, listed on Google as “HVAC contractor”.
Based in St. Charles
Ranked #16 because of its Google rating and trade focus: 4.9★ from 58 Google reviews, listed on Google as “Heating contractor”.
Based in Dale City, 18 mi away
Ranked #17 because of its Google rating and trade focus: 4.9★ from 1,060 Google reviews, listed on Google as “HVAC contractor”.
Based in Lorton, 16 mi away
Ranked #18 because of its Google rating and trade focus: 4.9★ from 770 Google reviews, listed on Google as “HVAC contractor”.
Based in Alexandria, 17 mi away
Ranked #19 because of its Google rating and trade focus: 4.8★ from 1,318 Google reviews, listed on Google as “HVAC contractor”.
Based in St. Charles
Ranked #20 because of its Google rating and trade focus: 4.9★ from 1,208 Google reviews, listed on Google as “HVAC contractor”.
Based in Lorton, 16 mi away
Ranked #21 because of its Google rating and trade focus: 4.8★ from 908 Google reviews, listed on Google as “HVAC contractor”.
Based in Alexandria, 16 mi away
Ranked #22 because of its Google rating and trade focus: 4.9★ from 508 Google reviews, listed on Google as “HVAC contractor”.
Based in Lorton, 16 mi away
Ranked #23 because of its Google rating and trade focus: 4.8★ from 866 Google reviews, listed on Google as “HVAC contractor”.
Based in Greater Upper Marlboro, 22 mi away
Ranked #24 because of its Google rating and trade focus: 4.9★ from 1,421 Google reviews, listed on Google as “HVAC contractor”.
Based in Lorton, 16 mi away
Ranked #25 because of its Google rating and trade focus: 4.9★ from 507 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 559 ranked HVAC contractors here; the rest are on their profiles.
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 |
|---|---|---|
| A. B. Heating & Air Conditioning | In St. Charles | |
| ACCURATE | 4.9★ (208) | 20 mi |
| Ace HVAC & Airduct cleaning Conditioning | 4.5★ (2) | 8 mi |
| AGD Heating, Cooling, & Commercial Refrigeration | In St. Charles | |
| Airtron Heating & Air Conditioning | 2.5★ (2) | 8 mi |
| Alex Hvac Service LLC | 4.9★ (310) | 22 mi |
| Application Controls LLC | In St. Charles | |
| Back 2 Basic HVAC LLC | 5.0★ (2) | 13 mi |
| DKS Enterprise LLC | 5.0★ (2) | 9 mi |
| Jerry's Plumbing, Heating and Air Inc | 3.9★ (88) | 1 mi |
| JM INSULATION LLC | 5.0★ (2) | 8 mi |
| K 2 Ventilations | 5.0★ (2) | 1 mi |
| Logan Mechanical LLC | 4.7★ (155) | 12 mi |
| Mechanical Trade Services | In St. Charles | |
| None | In St. Charles | |
| Old line mechanical | In St. Charles | |
| R&R HVAC Solutions | 5.0★ (220) | 17 mi |
| Sears Heating and Air Conditioning | 3.0★ (2) | 1 mi |
| Thompson HVAC | In St. Charles | |
| TRINITY PRO SERVICES | 4.7★ (257) | 16 mi |
National price ranges in USD, not adjusted for St. Charles. 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 Maryland, Maryland State Board of Heating, Ventilation, Air-Conditioning and Refrigeration Contractors licenses Heating, ventilation, air conditioning and refrigeration work.
No chip usually means we have not matched a state record yet. Check the lookup yourself before you hire.
Guide checked October 2026. How we verify licenses
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 559 St. Charles 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 St. Charles 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 |