677 HVAC contractors ranked by CR ScoreUpdated 0 paid placements in this rankingHow we rank →
Best overall in Union City: Jazz Heating, Air Conditioning and Plumbing, CR Score 93/100; 4.9★ from 3,438 Google reviews; open 24/7.
Best for emergencies (open 24/7): Service Champions, posts 24/7 hours; ranked #2 of 677.
Most-reviewed: Service Champions, 4,721 Google reviews at 4.9★, the most of 677 ranked; ranked #2.
Rankings can't be bought. Contractors can't pay to change their rank or score. How we rank
677 Union City HVAC contractors are ranked here by CR Score, from 8 published factors. 195 are open 24/7, 450 open Saturdays and 364 open Sundays, based on posted hours. The median Google rating is 4.9★ across 677 rated businesses.
| Rank | Business | CR Score | Google rating | Based in | Hours | Best for |
|---|---|---|---|---|---|---|
| 1 | Jazz Heating, Air Conditioning and Plumbing | 93 | 4.9★ (3,438) | Pleasanton, 10 mi away | 24/7 | Overall |
| 2 | Service Champions | 93 | 4.9★ (4,721) | Livermore, 14 mi away | 24/7 | Emergencies, Most reviews |
| 3 | Heating And Air Experts - Affordable HVAC Contractor in Fremont, California | 93 | 5.0★ (761) | Fremont, 6 mi away | 24/7 | — |
| 4 | Service Champions | 92 | 4.8★ (2,337) | Pleasanton, 9 mi away | 24/7 | — |
| 5 | Service Champions | 92 | 4.9★ (3,407) | San Jose, 15 mi away | 24/7 | — |
| 6 | AIS Heating & Air Conditioning | 91 | 4.9★ (723) | Fremont, 7 mi away | 24/7 | — |
| 7 | Chill Heating and Cooling | 91 | 5.0★ (1,017) | San Ramon, 13 mi away | 24/7 | — |
| 8 | IRBIS Air Plumbing Electrical | 90 | 4.9★ (1,466) | San Jose, 15 mi away | 24/7 | — |
| 9 | Bell Brothers Plumbing Heating & Air - Hayward | 90 | 4.7★ (863) | Hayward, 6 mi away | 24/7 | — |
| 10 | Fuse service | 90 | 5.0★ (444) | Palo Alto, 13 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 in Union City
Based in Pleasanton, 10 mi away
Ranked #1 because of its Google rating and availability: 4.9★ from 3,438 Google reviews, open 24/7.
Based in Livermore, 14 mi away
Ranked #2 because of its Google rating and availability: 4.9★ from 4,721 Google reviews, open 24/7.
Based in Fremont, 6 mi away
Ranked #3 because of its Google rating and availability: 5.0★ from 761 Google reviews, open 24/7.
Based in Pleasanton, 9 mi away
Ranked #4 because of its Google rating and availability: 4.8★ from 2,337 Google reviews, open 24/7.
Based in San Jose, 15 mi away
Ranked #5 because of its Google rating and availability: 4.9★ from 3,407 Google reviews, open 24/7.
Based in Fremont, 7 mi away
Ranked #6 because of its Google rating and availability: 4.9★ from 723 Google reviews, open 24/7.
Based in San Ramon, 13 mi away
Ranked #7 because of its Google rating and availability: 5.0★ from 1,017 Google reviews, open 24/7.
Based in San Jose, 15 mi away
Ranked #8 because of its Google rating and availability: 4.9★ from 1,466 Google reviews, open 24/7.
Based in Hayward, 6 mi away
Ranked #9 because of its Google rating and availability: 4.7★ from 863 Google reviews, open 24/7.
Based in Palo Alto, 13 mi away
Ranked #10 because of its Google rating and availability: 5.0★ from 444 Google reviews, open 24/7.
Based in Santa Clara, 17 mi away
Ranked #11 because of its Google rating and availability: 4.9★ from 1,034 Google reviews, open 24/7.
Based in Hayward, 5 mi away
Ranked #12 because of its Google rating and availability: 4.9★ from 172 Google reviews, open 24/7.
Based in San Jose, 17 mi away
Ranked #13 because of its Google rating and availability: 4.9★ from 1,142 Google reviews, open 24/7.
Based in Livermore, 17 mi away
Ranked #14 because of its Google rating and availability: 4.9★ from 920 Google reviews, open 24/7.
Based in Hayward, 6 mi away
Ranked #15 because of its Google rating and availability: 4.5★ from 1,252 Google reviews, open 24/7.
Based in Hayward, 7 mi away
Ranked #16 because of its Google rating and availability: 4.9★ from 162 Google reviews, open 24/7.
Based in Menlo Park, 12 mi away
Ranked #17 because of its Google rating and availability: 5.0★ from 208 Google reviews, open 24/7.
Based in Danville, 16 mi away
Ranked #18 because of its Google rating and availability: 4.9★ from 602 Google reviews, open 24/7.
Based in Pleasanton, 10 mi away
Ranked #19 because of its Google rating and availability: 5.0★ from 153 Google reviews, open 24/7.
Based in Hayward, 5 mi away
Ranked #20 because of its Google rating and availability: 4.5★ from 700 Google reviews, open 24/7.
Based in Newark, 4 mi away
Ranked #21 because of its Google rating and availability: 4.8★ from 122 Google reviews, open 24/7.
Based in Livermore, 18 mi away
Ranked #22 because of its Google rating and availability: 4.9★ from 549 Google reviews, open 24/7.
Based in San Jose, 16 mi away
Ranked #23 because of its Google rating and availability: 4.9★ from 400 Google reviews, open 24/7.
Based in Livermore, 14 mi away
Ranked #24 because of its Google rating and availability: 5.0★ from 172 Google reviews, open 24/7.
Based in Hayward, 8 mi away
Ranked #25 because of its Google rating and availability: 4.6★ from 474 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 677 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 |
|---|---|---|
| Ackley Sheetmetal | 4.5★ (2) | 7 mi |
| Altai Heating & Air | 5.0★ (2) | 13 mi |
| Automatic Control Engineering | 4.5★ (2) | 7 mi |
| Barker Heating & Cooling | 4.8★ (1,930) | 19 mi |
| C F Archibald Paving | 5.0★ (2) | 12 mi |
| Comfy Heating & Air Conditioning Inc. | 4.8★ (111) | 11 mi |
| Commercial Filter Services | 3.0★ (2) | 12 mi |
| Eco Systems Heating & Air Conditioning | 4.8★ (138) | 12 mi |
| Faith Furnace & Duct Cleaning Service | 5.0★ (1) | In Union City |
| Furnace / AC repair service. Commercial refrigeration, HVAC | 5.0★ (2) | 3 mi |
| furnace air conditioning Man | In Union City | |
| Glover & Son Heating & Air Inc | 3.0★ (2) | 9 mi |
| Hayward duct cleaning & dryer solution | 5.0★ (2) | 8 mi |
| heating and furnace service | 4.0★ (2) | 4 mi |
| Insulation & Air Duct Crew | 5.0★ (2) | 6 mi |
| Jenson Mechanical Inc | In Union City | |
| Pacific Breeze Mechanical | 5.0★ (2) | 7 mi |
| rabboni mechanical | In Union City | |
| RCS Mechanical Services | 4.0★ (2) | 8 mi |
| RJA Group LLC | 3.0★ (2) | 9 mi |
National price ranges in USD, not adjusted for Union City. 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 California, Contractors State License Board (CSLB) licenses C-20 Warm-Air Heating, Ventilating and Air-Conditioning contractor license.
Jobs of $1,000 or more in labor and materials (from January 1, 2025).
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
California's HVAC demand peaks during summer heat waves and the first cold snaps. Spring and fall are the easiest times to book maintenance.
We scored 677 Union City 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 Union City 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 |