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ContractorsRanked

Best HVAC Contractors in Saint Charles, MD (2026)

585 HVAC contractors ranked by CR ScoreUpdated 0 paid placements in this rankingHow we rank →

The short answer

  1. 1

    Best overall in Saint Charles: Mission Comfort, CR Score 92/100; 5.0★ from 625 Google reviews; open 24/7.

  2. 2

    Best for emergencies (open 24/7): A-Plus Service Experts, posts 24/7 hours; ranked #2 of 585.

  3. 5

    Most-reviewed: Michael & Son Services, 15,537 Google reviews at 4.7★, the most of 585 ranked; ranked #5.

Rankings can't be bought. Contractors can't pay to change their rank or score. How we rank

585 Saint Charles HVAC contractors are ranked here by CR Score, from 8 published factors. 188 are open 24/7, 400 open Saturdays and 278 open Sundays, based on posted hours. The median Google rating is 4.9★ across 585 rated businesses.

Top 10 HVAC contractors in Saint Charles at a glance

Top 10 HVAC contractors in Saint Charles at a glance
RankBusinessCR ScoreGoogle ratingBased inHoursBest for
1Mission Comfort925.0★ (625)Waldorf, 2 mi away24/7Overall
2A-Plus Service Experts924.8★ (1,234)St. Charles, 1 mi away24/7Emergencies
3Olympic Aire Services Inc914.9★ (426)Accokeek, 1 mi away24/7—
4United Air Temp904.7★ (855)Waldorf, 2 mi away24/7—
5Michael & Son Services904.7★ (15,537)Alexandria, 18 mi away24/7Most reviews
6John C. Flood894.8★ (4,976)Alexandria, 18 mi away24/7—
7Fixed Right & Guaranteed Super Techs, LLC895.0★ (1,032)Rosaryville, 17 mi away24/7—
8Krafft Service Corporation894.9★ (1,631)Alexandria, 18 mi away24/7—
9United Air Temp894.8★ (1,775)Fort Washington, 15 mi away24/7—
10AZA heating, cooling, plumbing & construction895.0★ (959)Alexandria, 18 mi away24/7—

The 585 best HVAC contractors in Saint Charles, ranked

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.

  1. Ranked #1 in Saint Charles

    #1 Mission Comfort

    Based in Waldorf, 2 mi away

    92/100CR Score

    Ranked #1 because of its Google rating and availability: 5.0★ from 625 Google reviews, open 24/7.

    • 5.0★ from 625 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    11822 Pika Dr, Waldorf, MD 20602
    View profile for Mission Comfort(301) 450-5913

  4. #4 United Air Temp

    Based in Waldorf, 2 mi away

    90/100CR Score

    Ranked #4 because of its Google rating and availability: 4.7★ from 855 Google reviews, open 24/7.

    • 4.7★ from 855 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    605 Post Office Rd Ste 204, Waldorf, MD 20602
    View profile for United Air Temp(240) 359-9217

  5. #5 Michael & Son Services

    Based in Alexandria, 18 mi away

    90/100CR Score

    Ranked #5 because of its Google rating and review volume: 4.7★ from 15,537 Google reviews, the most Google reviews on this list (15,537).

    • 4.7★ from 15,537 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    5740 General Washington Dr, Alexandria, VA 22312
    View profile for Michael & Son Services(800) 948-6453

  6. #6 John C. Flood

    Based in Alexandria, 18 mi away

    89/100CR Score

    Ranked #6 because of its Google rating and availability: 4.8★ from 4,976 Google reviews, open 24/7.

    • 4.8★ from 4,976 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    6430 General Green Way, Alexandria, VA 22312
    View profile for John C. Flood(571) 605-7008

  9. #9 United Air Temp

    Based in Fort Washington, 15 mi away

    89/100CR Score

    Ranked #9 because of its Google rating and availability: 4.8★ from 1,775 Google reviews, open 24/7.

    • 4.8★ from 1,775 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    5620 St Barnabas Rd Ste 240, Fort Washington, MD 20744
    View profile for United Air Temp(240) 342-3956

  12. #12 HPC Services

    Based in Waldorf, 2 mi away

    88/100CR Score

    Ranked #12 because of its Google rating and availability: 4.9★ from 92 Google reviews, open 24/7.

    • 4.9★ from 92 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    14 Irongate Dr Suite F, Waldorf, MD 20602
    View profile for HPC Services(240) 435-7472

  15. #15 CroppMetcalfe

    Based in Fairfax, 25 mi away

    88/100CR Score

    Ranked #15 because of its Google rating and availability: 4.8★ from 7,638 Google reviews, open 24/7.

    • 4.8★ from 7,638 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    8421 Hilltop Rd, Fairfax, VA 22031
    View profile for CroppMetcalfe(703) 420-5030

  18. #18 United Air Temp

    Based in Alexandria, 17 mi away

    88/100CR Score

    Ranked #18 because of its Google rating and availability: 4.8★ from 1,318 Google reviews, open 24/7.

    • 4.8★ from 1,318 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    6094 Franconia Rd # B, Alexandria, VA 22310
    View profile for United Air Temp(703) 762-2488

  19. #19 Caffi Services

    Based in Alexandria, 16 mi away

    87/100CR Score

    Ranked #19 because of its Google rating and availability: 4.9★ from 508 Google reviews, open 24/7.

    • 4.9★ from 508 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    1313 Powhatan St, Alexandria, VA 22314
    View profile for Caffi Services(703) 962-6052

  22. #22 M.E. Flow

    Based in Lorton, 16 mi away

    87/100CR Score

    Ranked #22 because of its Google rating and availability: 4.8★ from 866 Google reviews, open 24/7.

    • 4.8★ from 866 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    7200 Telegraph Square Dr, Lorton, VA 22079
    View profile for M.E. Flow(571) 470-7235

HVAC contractors ranked #26 to #50

#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 585 ranked HVAC contractors here; the rest are on their profiles.

HVAC contractors in Saint Charles, ranks 26 to 50
RankBusinessCR ScoreGoogle ratingDistance
26A Action Home Services874.9★ (326)15 mi
27OHA HVAC, Plumbing, Chimney & Fireplaces874.9★ (1,794)25 mi
28M.E. Flow874.7★ (1,169)16 mi
29United Air Temp874.7★ (1,754)19 mi
30Lawson Air Conditioning Repair865.0★ (36)6 mi
31United Air Temp864.9★ (313)19 mi
32Comfort Solutions864.8★ (298)16 mi
33SMO Energy864.3★ (945)5 mi
34United Air Temp864.4★ (4,301)16 mi
35Associates Property Management, Inc.864.9★ (17)1 mi
36DR HVAC Inc864.9★ (348)20 mi
37KPK Enterprise Heating and Cooling855.0★ (320)11 mi
38Cardinal Plumbing Heating & Air Inc854.9★ (1,720)16 mi
39McCarthy Services854.4★ (3,547)17 mi
40NFS Heating & A/C Services LLC854.9★ (67)12 mi
41Alex Hvac Service LLC854.9★ (310)21 mi
42Len the Plumber Heating & Air, LLC854.7★ (6,899)17 mi
43Su' Coy Heating, AC & Duct Cleaning854.9★ (205)19 mi
44Michael & Son Services854.8★ (8,326)24 mi
45ACCURATE854.9★ (208)20 mi
46Su'Coy854.9★ (58)12 mi
47Cyprus Air Heating, Cooling and Fireplaces854.3★ (2,189)13 mi
48United Air Temp854.8★ (146)16 mi
49All Season Aire854.7★ (11)1 mi
50Trust Heating And AC Services844.9★ (348)25 mi

Also serving Saint Charles

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.

Unranked HVAC contractors serving Saint Charles
BusinessGoogle ratingDistance
(HVACR) Lord refrigeration3.0★ (2)17 mi
Ace HVAC & Airduct cleaning Conditioning4.5★ (2)8 mi
Airtron Heating & Air Conditioning2.5★ (2)8 mi
AY Comfort, Inc.5.0★ (2)17 mi
Back 2 Basic HVAC LLC5.0★ (2)13 mi
BBG Contracting4.5★ (2)14 mi
Construction Trade Services3.0★ (2)17 mi
DKS Enterprise LLC5.0★ (2)9 mi
DM Select Services5.0★ (2)15 mi
Homestead Handymen HVAC/R, LLC5.0★ (2)19 mi
Horizon Mechanical Services LLC5.0★ (2)17 mi
JM INSULATION LLC5.0★ (2)9 mi
K 2 Ventilations5.0★ (2)1 mi
Logan Mechanical LLC4.7★ (155)12 mi
R&R HVAC Solutions5.0★ (220)18 mi
S&W Controls, Inc.5.0★ (2)17 mi
Sears Heating and Air Conditioning3.0★ (2)1 mi
Sears Window Replacement2.5★ (2)18 mi
TRINITY PRO SERVICES4.7★ (257)16 mi
Ultra Painting HVAC Pros5.0★ (2)16 mi

How much do HVAC contractors cost in Saint Charles?

National price ranges in USD, not adjusted for Saint Charles. Each row names its basis and the month we checked it.

How much do HVAC contractors cost in Saint Charles?
JobLowTypicalHighBasisChecked
AC replacement$3,887$5,978$8,073Per system, installed (unit plus labor); typical range of customer-reported jobs. US national rangeOctober 2026
Furnace replacement$2,823$4,814$6,896Per system, installed; typical range of customer-reported jobs. US national rangeOctober 2026

How to check an HVAC contractor's license in Maryland

In Maryland, Maryland State Board of Heating, Ventilation, Air-Conditioning and Refrigeration Contractors licenses Heating, ventilation, air conditioning and refrigeration work.

  1. Check that the status is active and the name matches the contract or truck.
  2. Ask for proof of insurance before work starts.

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

When to hire an HVAC contractor in Maryland

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.

How we ranked Saint Charles HVAC contractors

We scored 585 Saint Charles 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.

Read the full method: formula, sources and exclusions

CR Score factors and weights
FactorWeightComputed fromIn Saint Charles data
Reputation35%Bayesian-adjusted Google star ratingMeasured
Credentials15%Active state license 0.6, bond 0.2, workers’ comp 0.2Not yet collected
Review volume10%log10(reviews + 1) against the list maximumMeasured
Recency10%Share of reviews from the last 12 monthsNot yet collected
Availability10%Weekly open hours, Saturday, Sunday, 24/7 or same-dayMeasured
Trade focus10%Google main category 1.0, business name 0.7, additional category 0.5Measured
Proximity5%1.0 when based in the city, falling to 0 at the trade’s radiusMeasured
Completeness5%Website, photos, description, hours, claimed profile (0.2 each)Measured

HVAC contractors in Saint Charles: frequently asked questions

Who is the best HVAC contractor in Saint Charles?

By CR Score, the highest-ranked HVAC contractor in Saint Charles, MD is Mission Comfort with a CR Score of 92/100. It has 5.0★ from 625 Google reviews. It is open 24/7. A-Plus Service Experts (#2) and Olympic Aire Services Inc (#3) follow. We ranked 585 HVAC contractors on 8 factors, last updated October 22, 2026.

How many HVAC contractors are there in Saint Charles?

ContractorsRanked ranks 585 HVAC contractors serving Saint Charles, MD. Another 20 within 25 mi are listed but not ranked yet. Counts are as of October 2026.

Which HVAC contractors in Saint Charles are open 24/7?

188 ranked HVAC contractors in Saint Charles post 24/7 hours. The highest-ranked are Mission Comfort (#1), A-Plus Service Experts (#2) and Olympic Aire Services Inc (#3). Hours come from each business's Google listing as of October 2026, so call to confirm.

Which HVAC contractors in Saint Charles work on weekends?

400 of 585 ranked HVAC contractors post Saturday hours and 278 post Sunday hours. The highest-ranked open Saturdays are Mission Comfort (#1), A-Plus Service Experts (#2) and Olympic Aire Services Inc (#3). Posted hours are office hours; crews may book weekend jobs separately.

How do I check an HVAC contractor's license in Maryland?

In Maryland, Maryland State Board of Heating, Ventilation, Air-Conditioning and Refrigeration Contractors handles licensing and covers Heating, ventilation, air conditioning and refrigeration work.

How much does ac replacement cost in Saint Charles?

AC replacement typically costs $3,887 to $8,073, with $5,978 typical (Per system, installed (unit plus labor); typical range of customer-reported jobs. US national range). This is a national range, not adjusted for Saint Charles. Prices were last checked October 2026. Get at least two written quotes before you hire.

What Google rating do Saint Charles HVAC contractors have?

The median Google rating among 585 rated HVAC contractors in Saint Charles is 4.9★, with a median of 18 reviews. Michael & Son Services has the most, 15,537 reviews, and ranks #5. We adjust ratings for review count, so a few five-star reviews cannot top the list.

When is the best time to hire an HVAC contractor in Saint Charles?

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.

Update log for Saint Charles

  1. October 2026: CR Scores recalculated for 585 hvac contractors serving Saint Charles.
  2. October 2026: 9 duplicate listings merged.

More HVAC contractors and Saint Charles pages

Other trades in Saint Charles