465 HVAC contractors ranked by CR ScoreUpdated 0 paid placements in this rankingHow we rank →
Best overall in Green Valley: GAC Services, CR Score 93/100; 4.9★ from 6,908 Google reviews; open 24/7.
Best for emergencies (open 24/7): Presidential, Inc., posts 24/7 hours; ranked #2 of 465.
Most-reviewed: F.H. Furr Plumbing, Heating, Air Conditioning & Electrical, 5,985 Google reviews at 4.7★, the most of 465 ranked after GAC Services; ranked #7.
Rankings can't be bought. Contractors can't pay to change their rank or score. How we rank
465 Green Valley HVAC contractors are ranked here by CR Score, from 8 published factors. 133 are open 24/7, 295 open Saturdays and 205 open Sundays, based on posted hours. The median Google rating is 4.9★ across 465 rated businesses.
| Rank | Business | CR Score | Google rating | Based in | Hours | Best for |
|---|---|---|---|---|---|---|
| 1 | GAC Services | 93 | 4.9★ (6,908) | Gaithersburg, 13 mi away | 24/7 | Overall |
| 2 | Presidential, Inc. | 91 | 4.9★ (1,701) | Gaithersburg, 12 mi away | 24/7 | Emergencies |
| 3 | Wenbrooke Services - Electrical, Plumbing, Heating and Air | 91 | 4.8★ (1,208) | Frederick, 8 mi away | 24/7 | — |
| 4 | Michael Bonsby HVAC, Plumbing & Electrical | 91 | 4.8★ (2,083) | Gaithersburg, 12 mi away | 24/7 | — |
| 5 | Larry & Sons Plumbing, Heating, Cooling, Drain & Electrical | 90 | 4.8★ (932) | Frederick, 9 mi away | 24/7 | — |
| 6 | Parker Pearce Service Experts | 90 | 4.8★ (1,700) | Gaithersburg, 12 mi away | 24/7 | — |
| 7 | F.H. Furr Plumbing, Heating, Air Conditioning & Electrical | 90 | 4.7★ (5,985) | Rockville, 17 mi away | 24/7 | Most reviews |
| 8 | Smock Heating & Air | 90 | 5.0★ (1,623) | Frederick, 8 mi away | Sat · Sun · Evenings | — |
| 9 | Markool Heating Cooling Plumbing | 90 | 4.9★ (547) | Frederick, 11 mi away | 24/7 | — |
| 10 | Urbana HVAC | 90 | 5.0★ (182) | Ballenger Creek, 7 mi away | 24/7 | — |
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 because of its Google rating and review volume: 4.9★ from 6,908 Google reviews, the most Google reviews on this list (6,908).
Based in Gaithersburg, 12 mi away
Ranked #2 because of its Google rating and availability: 4.9★ from 1,701 Google reviews, open 24/7.
Based in Frederick, 8 mi away
Ranked #3 because of its Google rating and availability: 4.8★ from 1,208 Google reviews, open 24/7.
Based in Gaithersburg, 12 mi away
Ranked #4 because of its Google rating and availability: 4.8★ from 2,083 Google reviews, open 24/7.
Based in Frederick, 9 mi away
Ranked #5 because of its Google rating and availability: 4.8★ from 932 Google reviews, open 24/7.
Based in Gaithersburg, 12 mi away
Ranked #6 because of its Google rating and availability: 4.8★ from 1,700 Google reviews, open 24/7.
Based in Rockville, 17 mi away
Ranked #7 because of its Google rating and availability: 4.7★ from 5,985 Google reviews, open 24/7.
Based in Frederick, 8 mi away
Ranked #8 because of its Google rating and trade focus: 5.0★ from 1,623 Google reviews, listed on Google as “HVAC contractor”.
Based in Frederick, 11 mi away
Ranked #9 because of its Google rating and availability: 4.9★ from 547 Google reviews, open 24/7.
Based in Ballenger Creek, 7 mi away
Ranked #10 because of its Google rating and availability: 5.0★ from 182 Google reviews, open 24/7.
Based in Sterling, 21 mi away
Ranked #11 because of its Google rating and availability: 5.0★ from 1,428 Google reviews, open 24/7.
Based in Leesburg, 20 mi away
Ranked #12 because of its Google rating and availability: 4.8★ from 3,718 Google reviews, open 24/7.
Based in Frederick, 9 mi away
Ranked #13 because of its Google rating and availability: 4.8★ from 537 Google reviews, open 24/7.
Based in Sterling, 23 mi away
Ranked #14 because of its Google rating and availability: 4.9★ from 2,958 Google reviews, open 24/7.
Based in Frederick, 8 mi away
Ranked #15 because of its Google rating and availability: 4.8★ from 414 Google reviews, open 24/7.
Based in Mount Airy, 9 mi away
Ranked #16 because of its Google rating and availability: 4.7★ from 852 Google reviews, open 24/7.
Based in Sterling, 24 mi away
Ranked #17 because of its Google rating and availability: 4.9★ from 2,807 Google reviews, open 24/7.
Based in Gaithersburg, 12 mi away
Ranked #18 because of its Google rating and availability: 4.8★ from 666 Google reviews, open 24/7.
Based in Frederick, 8 mi away
Ranked #19 because of its Google rating and trade focus: 4.9★ from 1,614 Google reviews, listed on Google as “HVAC contractor”.
Based in Ashburn, 20 mi away
Ranked #20 because of its Google rating and availability: 4.8★ from 2,314 Google reviews, open 24/7.
Based in Clarksburg, 12 mi away
Ranked #21 because of its Google rating and availability: 4.9★ from 361 Google reviews, open 24/7.
Based in Sterling, 24 mi away
Ranked #22 because of its Google rating and availability: 4.8★ from 5,283 Google reviews, open 24/7.
Based in Frederick, 11 mi away
Ranked #23 because of its Google rating and availability: 4.7★ from 928 Google reviews, open 24/7.
Based in Sterling, 22 mi away
Ranked #24 because of its Google rating and availability: 4.9★ from 1,501 Google reviews, open 24/7.
Based in Ashburn, 21 mi away
Ranked #25 because of its Google rating and availability: 5.0★ from 710 Google reviews, open 24/7.
#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 465 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 Blessing Mechanical, LLC | 5.0★ (2) | 15 mi |
| Air Zone Systems, Inc | 5.0★ (2) | 22 mi |
| AM/PM Emergency Services a division of Robert E Clubb & Associates | 5.0★ (2) | 6 mi |
| Brick Street Plumbing & HVAC | 4.2★ (364) | 9 mi |
| Davis Plumbing & Heating Inc | 5.0★ (2) | 19 mi |
| Green HVAC Services | 5.0★ (2) | 19 mi |
| Heating & Cooling Certified Mechanic LLC | 5.0★ (2) | 20 mi |
| Home Services at The Home Depot | 3.5★ (2) | 8 mi |
| Home Services at The Home Depot | 1.0★ (2) | 20 mi |
| JC & JC HVAC | 4.7★ (503) | 22 mi |
| Mayne Source Heating & Air | 5.0★ (2) | 9 mi |
| Michael & Son Services | 4.7★ (419) | 23 mi |
| Mt Airy Heating & Air Conditioning | 5.0★ (2) | 9 mi |
| Owens & Johnsons Heating and Cooling | 3.0★ (2) | 19 mi |
| P W Scholl Plumbing & Heating Inc | 5.0★ (2) | 6 mi |
| Redline Mechanical Services | 4.9★ (16) | In Green Valley |
| Rockville Heating & Air Services | 5.0★ (2) | 15 mi |
| S.L. Johnson Plumbing & Heating | 3.0★ (2) | 17 mi |
| Seneff Heating & Air Inc | 5.0★ (2) | 21 mi |
| Vito Services | 4.7★ (1,351) | 17 mi |
National price ranges in USD, not adjusted for Green Valley. 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 465 Green Valley 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 Green Valley 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 |