Top 50 of 1,311 HVAC contractors, in emergency orderUpdated 0 paid placements in this rankingHow we rank
25 of the 50 HVAC contractors on this list post 24/7 hours. 24/7 businesses come first, then same-day, each ranked by CR Score with availability weighted higher.
#1 for emergency heating and cooling in Diamond Bar: All Pro Cooling, Heating, Plumbing & Electrical, open 24/7.
Rankings can't be bought. Contractors can't pay to change their rank or score. How we rank
| Rank | Business | CR Score | Google rating | Based in | Hours |
|---|---|---|---|---|---|
| 1 | All Pro Cooling, Heating, Plumbing & Electrical | 64 | 4.8★ (7,425) | Ontario, 16 mi away | 24/7 |
| 2 | Service Hero Plumbing, HVAC, and Electrical | 64 | 4.8★ (1,506) | Covina, 7 mi away | 24/7 |
| 3 | Metz Air Control | 64 | 4.9★ (969) | Chino, 7 mi away | 24/7 |
| 4 | Steve's Five Star Service | 64 | 4.9★ (1,292) | Upland, 9 mi away | 24/7 |
| 5 | Home Comfort USA | 64 | 4.8★ (2,813) | Anaheim, 12 mi away | 24/7 |
| 6 | Klaus & Sons Plumbing, Heating & Air Conditioning | 63 | 4.9★ (977) | Montclair, 9 mi away | 24/7 |
| 7 | NexGen HVAC & Plumbing | 63 | 4.7★ (2,250) | Anaheim, 12 mi away | 24/7 |
| 8 | Rooter Hero Plumbing & Air | 63 | 4.8★ (802) | Montclair, 8 mi away | 24/7 |
| 9 | Air Concepts Air Conditioning and Heating | 63 | 4.9★ (995) | Anaheim, 12 mi away | 24/7 |
| 10 | Veteran Air | 63 | 4.9★ (1,091) | Anaheim, 13 mi away | 24/7 |
24/7 hours mean the business says its phone is answered around the clock. Arrival time depends on where the crew is. Ask for an arrival window when you call.
#1All Pro Cooling, Heating, Plumbing & Electrical
Open 24/7 · 4.8 from 7,425 Google reviews
#2Service Hero Plumbing, HVAC, and Electrical
Open 24/7 · 4.8 from 1,506 Google reviews
Open 24/7 · 4.9 from 969 Google reviews
Open 24/7 · 4.9 from 1,292 Google reviews
Open 24/7 · 4.8 from 2,813 Google reviews
#6Klaus & Sons Plumbing, Heating & Air Conditioning
Open 24/7 · 4.9 from 977 Google reviews
Open 24/7 · 4.7 from 2,250 Google reviews
Open 24/7 · 4.8 from 802 Google reviews
24/7 first, then same-day service, then the rest. Each group is in CR Score order on emergency weights. The full ranking of all 1,311 is on the HVAC contractors page.
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 in Diamond Bar
Based in Ontario, 16 mi away
Ranked #1 because of its Google rating and review volume: 4.8★ from 7,425 Google reviews.
Based in Covina, 7 mi away
Ranked #2 because of its Google rating and trade focus: 4.8★ from 1,506 Google reviews, listed on Google as “HVAC contractor”.
Based in Chino, 7 mi away
Ranked #3 because of its Google rating and trade focus: 4.9★ from 969 Google reviews, listed on Google as “Air conditioning repair service”.
Based in Upland, 9 mi away
Ranked #4 because of its Google rating and trade focus: 4.9★ from 1,292 Google reviews, listed on Google as “Air conditioning contractor”.
Based in Anaheim, 12 mi away
Ranked #5 because of its Google rating and trade focus: 4.8★ from 2,813 Google reviews, listed on Google as “HVAC contractor”.
Based in Montclair, 9 mi away
Ranked #6 because of its Google rating and trade focus: 4.9★ from 977 Google reviews, listed on Google as “HVAC contractor”.
Based in Anaheim, 12 mi away
Ranked #7 because of its Google rating and trade focus: 4.7★ from 2,250 Google reviews, listed on Google as “HVAC contractor”.
Based in Montclair, 8 mi away
Ranked #8 because of its Google rating and trade focus: 4.8★ from 802 Google reviews, listed on Google as “HVAC contractor”.
Based in Anaheim, 12 mi away
Ranked #9 because of its Google rating and trade focus: 4.9★ from 995 Google reviews, listed on Google as “HVAC contractor”.
Based in Anaheim, 13 mi away
Ranked #10 because of its Google rating and trade focus: 4.9★ from 1,091 Google reviews, listed on Google as “HVAC contractor”.
Based in Brea, 9 mi away
Ranked #11 because of its Google rating and trade focus: 4.9★ from 547 Google reviews, listed on Google as “HVAC contractor”.
Based in Corona, 15 mi away
Ranked #12 because of its Google rating and trade focus: 4.9★ from 1,325 Google reviews, listed on Google as “HVAC contractor”.
Based in Yorba Linda, 11 mi away
Ranked #13 because of its Google rating and trade focus: 4.9★ from 764 Google reviews, listed on Google as “Air conditioning contractor”.
Based in San Dimas, 5 mi away
Ranked #14 because of its Google rating and trade focus: 4.9★ from 251 Google reviews, listed on Google as “HVAC contractor”.
Based in Covina, 6 mi away
Ranked #15 because of its Google rating and trade focus: 4.7★ from 426 Google reviews, listed on Google as “HVAC contractor”.
Based in Diamond Bar
Ranked #16 because of its Google rating and trade focus: 4.9★ from 89 Google reviews, listed on Google as “HVAC contractor”.
Based in Orange, 16 mi away
Ranked #17 because of its Google rating and trade focus: 4.8★ from 1,840 Google reviews, listed on Google as “HVAC contractor”.
Based in Brea, 10 mi away
Ranked #18 because of its Google rating and trade focus: 4.9★ from 439 Google reviews, listed on Google as “HVAC contractor”.
Based in Corona, 20 mi away
Ranked #19 because of its Google rating and trade focus: 4.7★ from 4,107 Google reviews, listed on Google as “HVAC contractor”.
Based in Santa Ana, 21 mi away
Ranked #20 because of its Google rating and trade focus: 4.9★ from 2,852 Google reviews, listed on Google as “HVAC contractor”.
Based in Corona, 16 mi away
Ranked #21 because of its Google rating and trade focus: 4.9★ from 1,213 Google reviews, listed on Google as “HVAC contractor”.
Based in Rancho Cucamonga, 13 mi away
Ranked #22 because of its Google rating and trade focus: 4.9★ from 705 Google reviews, listed on Google as “Air conditioning contractor”.
Based in La Puente, 7 mi away
Ranked #23 because of its Google rating and trade focus: 4.8★ from 333 Google reviews, listed on Google as “HVAC contractor”.
Based in Westminster, 22 mi away
Ranked #24 because of its Google rating and trade focus: 4.8★ from 4,319 Google reviews, listed on Google as “HVAC contractor”.
Based in Brea, 10 mi away
Ranked #25 because of its Google rating and trade focus: 4.8★ from 402 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.
Emergency lists move 10 points of the CR Score from reputation to availability: 15% and 15%. Availability credits 24/7 hours, same-day service, weekend hours and weekly open hours. 24/7 HVAC contractors are listed first, then same-day, then the rest; ranks follow that order. Paid placement never changes a rank.
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 |
|---|---|---|
| Reputation | 15% | Google star rating, adjusted for how many reviews back it |
| Credentials | 15% | Active state license, bond and workers’ comp on file |
| Review volume | 10% | Number of Google reviews, compared with the most-reviewed business on the list |
| Recency | 5% | Share of reviews from the last 12 months |
| Availability | 15% | Weekly open hours, Saturday, Sunday, 24/7 or same-day |
| Trade focus | 10% | How clearly the business does this trade (its Google category and name) |
| Proximity | 5% | Based in the city scores highest, less the farther away it is |
| Claimed profile | 10% | The business has claimed its ContractorsRanked profile (free or paid earn the same) |
| Partnered | 5% | The business links to ContractorsRanked from its own website with our badge, checked periodically |
| ContractorsRanked reviews | 10% | Verified customer reviews collected by ContractorsRanked: their rating and how many there are |