95/100CR Score
Ranked #1 because of its Google rating and availability: 4.9★ from 6,908 Google reviews, open 24/7.
- 4.9★ from 6,908 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 227 E Deer Park Dr, Gaithersburg, MD 20877
Best HVAC Contractors in Gaithersburg, MD (2026)
1,005 HVAC contractors ranked by CR ScoreUpdated 0 paid placements in this rankingHow we rank →
The short answer
- 1
Best overall in Gaithersburg: GAC Services, CR Score 95/100; 4.9★ from 6,908 Google reviews; open 24/7.
- 2
Best for emergencies (open 24/7): Presidential, Inc., posts 24/7 hours; ranked #2 of 1,005.
- 25
Most-reviewed: Michael & Son Services, 15,537 Google reviews at 4.7★, the most of 1,005 ranked; ranked #25.
Rankings can't be bought. Contractors can't pay to change their rank or score. How we rank
1,005 Gaithersburg HVAC contractors are ranked here by CR Score, from 8 published factors. 294 are open 24/7, 677 open Saturdays and 471 open Sundays, based on posted hours. The median Google rating is 4.9★ across 1,005 rated businesses.
Top 10 HVAC contractors in Gaithersburg at a glance
| Rank | Business | CR Score | Google rating | Based in | Hours | Best for |
|---|---|---|---|---|---|---|
| 1 | GAC Services | 95 | 4.9★ (6,908) | Gaithersburg | 24/7 | Overall |
| 2 | Presidential, Inc. | 93 | 4.9★ (1,701) | Gaithersburg | 24/7 | Emergencies |
| 3 | Michael Bonsby HVAC, Plumbing & Electrical | 93 | 4.8★ (2,083) | Gaithersburg | 24/7 | — |
| 4 | Parker Pearce Service Experts | 92 | 4.8★ (1,700) | Gaithersburg | 24/7 | — |
| 5 | F.H. Furr Plumbing, Heating, Air Conditioning & Electrical | 92 | 4.7★ (5,985) | Rockville, 5 mi away | 24/7 | — |
| 6 | Cool Breeze Plumbing, Heating & A/C | 91 | 4.8★ (666) | Gaithersburg | 24/7 | — |
| 7 | Metro Services HVAC | 91 | 4.9★ (298) | Gaithersburg | 24/7 | — |
| 8 | Meade's Heating and Air | 90 | 5.0★ (1,428) | Sterling, 14 mi away | 24/7 | — |
| 9 | Cardinal Plumbing Heating & Air Inc | 90 | 4.9★ (2,958) | Sterling, 16 mi away | 24/7 | — |
| 10 | Cyprus Air Heating, Cooling and Fireplaces | 90 | 4.7★ (1,402) | Rockville, 6 mi away | 24/7 | — |
The 1,005 best HVAC contractors in Gaithersburg, 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.
Based in Gaithersburg
93/100CR ScoreRanked #2 because of its Google rating and availability: 4.9★ from 1,701 Google reviews, open 24/7.
- 4.9★ from 1,701 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 8000 Cessna Ave, Gaithersburg, MD 20879
Based in Gaithersburg
93/100CR ScoreRanked #3 because of its Google rating and availability: 4.8★ from 2,083 Google reviews, open 24/7.
- 4.8★ from 2,083 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 7940 Cessna Ave, Gaithersburg, MD 20879
Based in Gaithersburg
92/100CR ScoreRanked #4 because of its Google rating and availability: 4.8★ from 1,700 Google reviews, open 24/7.
- 4.8★ from 1,700 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 7901 Beechcraft Ave Suite C, Gaithersburg, MD 20879
Based in Rockville, 5 mi away
92/100CR ScoreRanked #5 because of its Google rating and availability: 4.7★ from 5,985 Google reviews, open 24/7.
- 4.7★ from 5,985 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 685 Lofstrand Ln, Rockville, MD 20850
Based in Gaithersburg
91/100CR ScoreRanked #6 because of its Google rating and availability: 4.8★ from 666 Google reviews, open 24/7.
- 4.8★ from 666 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 18918 Premiere Ct, Gaithersburg, MD 20879
Based in Gaithersburg
91/100CR ScoreRanked #7 because of its Google rating and availability: 4.9★ from 298 Google reviews, open 24/7.
- 4.9★ from 298 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 30 N Summit Ave Unit 2, Gaithersburg, MD 20877
Based in Sterling, 14 mi away
90/100CR ScoreRanked #8 because of its Google rating and availability: 5.0★ from 1,428 Google reviews, open 24/7.
- 5.0★ from 1,428 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 45975 Nokes Blvd Suite 100, Sterling, VA 20166
Based in Sterling, 16 mi away
90/100CR ScoreRanked #9 because of its Google rating and availability: 4.9★ from 2,958 Google reviews, open 24/7.
- 4.9★ from 2,958 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 104 Carpenter Dr Suite D, Sterling, VA 20164
Based in Rockville, 6 mi away
90/100CR ScoreRanked #10 because of its Google rating and availability: 4.7★ from 1,402 Google reviews, open 24/7.
- 4.7★ from 1,402 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 802 Rockville Pike, Rockville, MD 20852
#11 Making Air Right
Based in Clarksburg, 5 mi away
90/100CR ScoreRanked #11 because of its Google rating and availability: 4.9★ from 361 Google reviews, open 24/7.
- 4.9★ from 361 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
Based in Sterling, 17 mi away
90/100CR ScoreRanked #12 because of its Google rating and availability: 4.9★ from 2,807 Google reviews, open 24/7.
- 4.9★ from 2,807 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 101-A Executive Dr STE 200, Sterling, VA 20166
#13 CroppMetcalfe
Based in Fairfax, 19 mi away
90/100CR ScoreRanked #13 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
Based in Gaithersburg
90/100CR ScoreRanked #14 because of its Google rating and availability: 5.0★ from 85 Google reviews, open 24/7.
- 5.0★ from 85 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 18622 Cross Country Ln, Gaithersburg, MD 20879
Based in Sterling, 17 mi away
89/100CR ScoreRanked #15 because of its Google rating and availability: 4.8★ from 5,283 Google reviews, open 24/7.
- 4.8★ from 5,283 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 22977 Eaglewood Ct STE 130, Sterling, VA 20166
Based in Silver Spring, 13 mi away
89/100CR ScoreRanked #16 because of its Google rating and availability: 4.6★ from 8,136 Google reviews, open 24/7.
- 4.6★ from 8,136 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 550 Forest Glen Rd, Silver Spring, MD 20901
Based in Sterling, 15 mi away
89/100CR ScoreRanked #17 because of its Google rating and availability: 4.9★ from 1,501 Google reviews, open 24/7.
- 4.9★ from 1,501 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 45681 Oakbrook Ct STE 101, Sterling, VA 20166
Based in Ashburn, 15 mi away
89/100CR ScoreRanked #18 because of its Google rating and availability: 4.8★ from 2,314 Google reviews, open 24/7.
- 4.8★ from 2,314 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 20145 Ashbrook Pl #110, Ashburn, VA 20147
Based in Sterling, 14 mi away
89/100CR ScoreRanked #19 because of its Google rating and availability: 4.8★ from 1,701 Google reviews, open 24/7.
- 4.8★ from 1,701 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 45921 Maries Rd, Sterling, VA 20166
#20 M.E. Flow
Based in Leesburg, 19 mi away
89/100CR ScoreRanked #20 because of its Google rating and availability: 4.8★ from 3,718 Google reviews, open 24/7.
- 4.8★ from 3,718 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 12 Cardinal Park Dr SE STE 107, Leesburg, VA 20175
#21 Mario Bro, LLC
Based in Gaithersburg
89/100CR ScoreRanked #21 because of its Google rating and availability: 5.0★ from 53 Google reviews, open 24/7.
- 5.0★ from 53 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 18745 Blue Violet Ln, Gaithersburg, MD 20879
Based in Fairfax, 18 mi away
89/100CR ScoreRanked #22 because of its Google rating and availability: 4.9★ from 1,794 Google reviews, open 24/7.
- 4.9★ from 1,794 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 2800 Juniper St #10, Fairfax, VA 22031
#23 United Air Temp
Based in Sterling, 16 mi away
89/100CR ScoreRanked #23 because of its Google rating and availability: 4.8★ from 2,161 Google reviews, open 24/7.
- 4.8★ from 2,161 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 45570 Shepard Dr Ste. #6, Sterling, VA 20164
Based in Ashburn, 17 mi away
88/100CR ScoreRanked #24 because of its Google rating and availability: 5.0★ from 710 Google reviews, open 24/7.
- 5.0★ from 710 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 20931 Ashburn Rd Suite 200, Ashburn, VA 20147
Based in Alexandria, 24 mi away
88/100CR ScoreRanked #25 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
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 1,005 ranked HVAC contractors here; the rest are on their profiles.
Also serving Gaithersburg
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 Blessing Mechanical, LLC | 5.0★ (2) | 4 mi |
| Apex Home Solutions | 1.0★ (1) | In Gaithersburg |
| Benjamin Franklin Plumbing of Gaithersburg | 4.9★ (165) | In Gaithersburg |
| Boland Supply | 5.0★ (1) | In Gaithersburg |
| Bryant Group, Inc | 4.0★ (66) | In Gaithersburg |
| Densel Company | In Gaithersburg | |
| Forced Air Systems | In Gaithersburg | |
| Global Construction & Mechanical | 1.0★ (1) | In Gaithersburg |
| H L Harris Plumbing & Heating | 5.0★ (1) | In Gaithersburg |
| Home Services at The Home Depot | 3.5★ (2) | 5 mi |
| JC & JC HVAC | 4.7★ (503) | 12 mi |
| Larry & Sons Plumbing, Heating, Cooling, Drain & Electrical | 4.8★ (932) | 21 mi |
| Maryland Plumbing & Heating | In Gaithersburg | |
| P W Scholl Plumbing & Heating Inc | 5.0★ (2) | 7 mi |
| R&V HVAC Services | In Gaithersburg | |
| Rockville Heating & Air Services | 5.0★ (2) | 3 mi |
| S.L. Johnson Plumbing & Heating | 3.0★ (2) | 5 mi |
| Sears Siding | 5.0★ (1) | In Gaithersburg |
| Tuckers AC & Heating LLC | 5.0★ (1) | In Gaithersburg |
| Vito Services | 4.7★ (1,351) | 5 mi |
How much do HVAC contractors cost in Gaithersburg?
National price ranges in USD, not adjusted for Gaithersburg. 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 |
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.
- Check that the status is active and the name matches the contract or truck.
- 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 Gaithersburg HVAC contractors
We scored 1,005 Gaithersburg 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 Gaithersburg 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 |
HVAC contractors in Gaithersburg: frequently asked questions
Who is the best HVAC contractor in Gaithersburg?
By CR Score, the highest-ranked HVAC contractor in Gaithersburg, MD is GAC Services with a CR Score of 95/100. It has 4.9★ from 6,908 Google reviews. It is open 24/7. Presidential, Inc. (#2) and Michael Bonsby HVAC, Plumbing & Electrical (#3) follow. We ranked 1,005 HVAC contractors on 8 factors, last updated October 22, 2026.
How many HVAC contractors are there in Gaithersburg?
ContractorsRanked ranks 1,005 HVAC contractors serving Gaithersburg, MD. 10 of them are based in Gaithersburg; the rest serve it from nearby towns. Another 20 within 25 mi are listed but not ranked yet. Counts are as of October 2026.
Which HVAC contractors in Gaithersburg are open 24/7?
294 ranked HVAC contractors in Gaithersburg post 24/7 hours. The highest-ranked are GAC Services (#1), Presidential, Inc. (#2) and Michael Bonsby HVAC, Plumbing & Electrical (#3). Hours come from each business's Google listing as of October 2026, so call to confirm.
Which HVAC contractors in Gaithersburg work on weekends?
677 of 1,005 ranked HVAC contractors post Saturday hours and 471 post Sunday hours. The highest-ranked open Saturdays are GAC Services (#1), Presidential, Inc. (#2) and Michael Bonsby HVAC, Plumbing & Electrical (#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 Gaithersburg?
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 Gaithersburg. Prices were last checked October 2026. Get at least two written quotes before you hire.
What Google rating do Gaithersburg HVAC contractors have?
The median Google rating among 1,005 rated HVAC contractors in Gaithersburg is 4.9★, with a median of 24 reviews. Michael & Son Services has the most, 15,537 reviews, and ranks #25. 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 Gaithersburg?
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 Gaithersburg
- October 2026: CR Scores recalculated for 1,005 hvac contractors serving Gaithersburg.
- October 2026: 7 duplicate listings merged.
More HVAC contractors and Gaithersburg pages
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Other trades in Gaithersburg
- Roofers in Gaithersburg1543 ranked
- Plumbers in Gaithersburg805 ranked
- Electricians in Gaithersburg708 ranked
- General contractors in Gaithersburg1539 ranked
- Painters in Gaithersburg285 ranked
- Landscapers in Gaithersburg320 ranked
- Handymen in Gaithersburg172 ranked
- Kitchen remodelers in Gaithersburg1188 ranked
- Bathroom remodelers in Gaithersburg1182 ranked
- Flooring contractors in Gaithersburg806 ranked
- Tile installers in Gaithersburg83 ranked
- Drywall contractors in Gaithersburg12 ranked
- Concrete contractors in Gaithersburg334 ranked
- Fence contractors in Gaithersburg194 ranked
- Deck builders in Gaithersburg461 ranked
- Siding contractors in Gaithersburg663 ranked
- Window installers in Gaithersburg730 ranked
- Gutter installers in Gaithersburg361 ranked
- Insulation contractors in Gaithersburg140 ranked
- Solar installers in Gaithersburg196 ranked
- Garage door repair companies in Gaithersburg166 ranked
- Foundation repair companies in Gaithersburg219 ranked
- Tree services in Gaithersburg332 ranked
- Masonry contractors in Gaithersburg323 ranked
- Water damage restoration companies in Gaithersburg891 ranked
- Home builders in Gaithersburg813 ranked
- Demolition contractors in Gaithersburg90 ranked
- All contractors in Gaithersburg