Pros411

HVAC contractors in Diamond Bar, CA

AC & heating

173 results

Sorted from nearest to farthest.

Registered and featured HVAC contractors

Other local businesses

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HVAC contractors in Diamond Bar, CA: by the numbers

There are 173 HVAC contractors with a phone number within 10 miles of Diamond Bar, CA, from public Google Maps data and state license records. 10 have a state license we could confirm, and those with a Google listing average 4.9 stars across 27,086 reviews.

with a phone number
173
with a confirmed state license
10
open 24 hours or for emergencies
63
come to you (service area)
14

Highest rated on Google near Diamond Bar, CA

Businesses with at least 20 Google reviews, sorted by rating. Ratings come from Google, not from Pros411.

  1. 1All City Plumbing, Air & Electrical5 ★ · 1,916 reviews · 9.7 mi
  2. 2Sano Plumbing Heating AC5 ★ · 1,128 reviews · 10 mi
  3. 3Haven Air Conditioning5 ★ · 617 reviews · 9.2 mi
  4. 4Eco Air Solutions5 ★ · 577 reviews · 9.4 mi
  5. 5Air Med Heating & Air Conditioning5 ★ · 333 reviews · 5.7 mi

Hours

Of the 150 businesses in this search that list their hours on Google, 128 are open on Saturdays and 99 on Sundays. 63 are open 24 hours. 77 have 4.5 stars or more with at least 10 reviews.

Good to know in Los Angeles

Los Angeles has a mild climate, but inland heat waves, Santa Ana winds in fall and winter, and a real wildfire risk, as the January 2025 Palisades and Eaton fires showed. Many homes are decades old, with older plumbing and electrical systems.

Weather and your home in Los Angeles (area)

days a year at 90°F or more
26
days a year at 100°F or more
2
freezing nights a year (32°F or below)
0
hail reports in Los Angeles County, 2016 to 2025 (5 of 1 inch or larger)
6
  • The hottest months are August and September. ncei.noaa.gov
  • Since January 1, 2023, a new central AC installed here must meet the Southwest regional standard: at least 14.3 SEER2 plus a minimum EER2, which measures efficiency in peak heat (for split systems under 45,000 BTU: 11.7, or 9.8 if the unit is 15.2 SEER2 or higher). eere.energy.gov
  • Palisades fire (January 7, 2025): 23,448 acres and 6,845 structures destroyed. fire.ca.gov
  • Eaton fire (January 7, 2025): 14,021 acres and 9,419 structures destroyed. fire.ca.gov

Heat and freezes: NOAA 1991-2020 climate normals at Downtown Los Angeles (USC campus) (USW00093134). Hail: NOAA Storm Events reports by county; they depend on how many people report, so use them to compare areas. Checked October 22, 2026. NOAA Storm Events

What an HVAC contractor charges

National ranges published by cost guides, not prices from the businesses on this list. Always get the price in writing.

  • Most AC repairs: about $150 to $700 (HomeGuide, HomeAdvisor, Fixr).
  • Service call or diagnostic: $75 to $200.
  • Capacitor: about $100 to $475; compressor: about $600 to $3,000, by source.
  • New central AC, installed: about $3,900 to $13,500 (HomeAdvisor, HomeGuide, Fixr, Trane).

AC repair cost: common repairs and when to replace · New AC unit cost: central air and mini-splits

Before you call

  • Check the thermostat, the breakers and the air filter first.
  • Have the brand and age of your system (on the label of the outdoor unit).
  • Ask about the diagnostic fee and after-hours rates.
  • If refrigerant is low, ask them to find and fix the leak, not just recharge.
  • Ask for the contractor’s license number.

Frequently asked questions

How many HVAC contractors are there in Diamond Bar, CA?

There are 173 with a phone number within 10 miles, from public Google Maps data and state license registries.

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

In California the license is issued by the Contractors State License Board (CSLB); you can look up the number at https://www.cslb.ca.gov. Pros411 shows "License verified" when the number is in that registry and matches the business phone. 10 of the HVAC contractors on this list have it confirmed.

Which HVAC contractors in Diamond Bar, CA have the best Google ratings?

Among those with at least 20 Google reviews, the highest rated in this search are All City Plumbing, Air & Electrical (5 stars, 1,916 reviews), Sano Plumbing Heating AC (5 stars, 1,128 reviews), Haven Air Conditioning (5 stars, 617 reviews).

Are there HVAC contractors open on weekends in Diamond Bar, CA?

Yes: of the 150 that list their hours, 128 are open on Saturdays and 99 on Sundays.

Are there 24-hour HVAC contractors in Diamond Bar, CA?

Yes: 63 list 24-hour hours or take emergency calls. Use the "24/7 emergencies" filter on the list.

Are there HVAC contractors who speak Spanish in Diamond Bar, CA?

Yes: 1 says on their website that they serve customers in Spanish (for example "Se habla español"). Use the "Speaks Spanish" filter on the list.

How do I contact an HVAC contractor?

Call or WhatsApp them directly from the list or their listing. Pros411 charges customers no fee and is not a middleman: you deal with the pro directly.

Why do some listings show first?

At the top, in a yellow box, are featured listings: they are paid and labeled "Featured". Then come registered pros, in the order they last bumped their listing, and at the end businesses from public data, from nearest to farthest.