| 'a' Plumbing And Heating | Michael Robert Niez | — | (909) 585 5203 | HVAC | Big Bear City · San Bernardino County | — | — |
| 1 AC Guys | Sahak Danielyan | — | (213) 444 4223 | HVAC | Panorama City · Los Angeles County | — | — |
| 1 Aircare HVAC | Hrek Oleksandr | — | (209) 281 5663 | HVAC | Oakdale · Stanislaus County | — | — |
| 1 Haro 1 LLC | Ruben Terriquez | — | (408) 464 4564 | HVAC | San Jose · Santa Clara County | — | — |
| 1 Hour Drain Hotshot Restoration | Robert John Gallaher | — | (408) 825 1362 | HVAC | San Jose · Santa Clara County | — | — |
| 1-800 Plumber + Air Of Monterey | David Charles De Cato | — | (831) 277 7258 | HVAC | Seaside · Monterey County | — | — |
| 1-800-coolness | Phillip Robert Paquin | — | (800) 266 5637 | HVAC | Fullerton · Orange County | — | — |
| 1-877 Appliance Repair INC | Ayriyan Gary | 1877appliance@gmail.com | (858) 222 9542 | HVAC | La Mesa · San Diego County | — | — |
| 1-888-heat-pumps | John Linus Grimsich | — | (888) 432 8786 | HVAC | Berkeley · Alameda County | — | — |
| 100 Degree Mechanical | 100 Degree Mechanical | — | (209) 278 7271 | HVAC | Stockton · San Joaquin County | — | — |
| 101 AC & Heating INC | Eugene Andrew Ayala | — | (805) 746 8582 | HVAC | Oxnard · Ventura County | — | — |
| 101 Plumbing Heating And Cooling | Felix De Jesus Gonzalez Escobar | — | (415) 488 7021 | HVAC | Novato · Marin County | — | — |
| 101 Refrigeration Service | Ahmadie Atef | — | (415) 755 3168 | HVAC | San Rafael · Marin County | — | — |
| 104 Air Heating And Cooling LLC | Martin Tejeda | — | (559) 567 3808 | HVAC | Madera · Madera County | — | — |
| 108 Mechanical | 108 Mechanical | — | (209) 648 2371 | HVAC | Knights Ferry · Stanislaus County | — | — |
| 10perature Heating And Air Conditioning | Perez Abraham Perez | — | (714) 610 4733 | HVAC | Garden Grove · Orange County | — | — |
| 11 11 Heating And Cooling | 11 11 Heating And Cooling | — | (909) 728 0848 | HVAC | San Bernardino · San Bernardino County | — | — |
| 110 Pro HVAC INC | Messbah Dast Gheib | — | (818) 590 6886 | HVAC | Encino · Los Angeles County | — | — |
| 1111 Heating And Air Conditioning | Jr Ubaldo Franco | — | (951) 963 6305 | HVAC | Corona · Riverside County | — | — |
| 1111 HVAC Services LLC | Jesse Clayton Anderson | — | (951) 519 3211 | HVAC | Menifee · Riverside County | — | — |
| 1153 San Rafael LLC | Najjarian Raman | — | (408) 712 4692 | HVAC | San Jose · Santa Clara County | — | — |
| 1800 Anytime Plumbing Heating & Air | Geno Anthony Gruber | — | (800) 269 8463 | HVAC | Coronado · San Diego County | — | — |
| 1st Call Refrigeration INC | Todd Anthony Garcia | — | (714) 951 6383 | HVAC | Whittier · Los Angeles County | — | — |
| 1st Choice Air Solutions | Moises Rene Vanegas | — | (323) 667 4149 | HVAC | San Bernardino · San Bernardino County | — | — |
| 1st Choice Heating & Air Conditioning INC | Christopher Scott Solar | — | (949) 305 5754 | HVAC | Lake Forest · Orange County | — | — |
| 1st Choice Plumbing Heating And Air | Fernando Andres Jr Rojas | — | (760) 696 1201 | HVAC | Oceanside · San Diego County | — | — |
| 1st Gen HVAC LLC | Fredy Jr Ruiz | — | (510) 375 9084 | HVAC | Richmond · Contra Costa County | — | — |
| 1st HVAC INC | Mostafa Mohammad Ashraf | — | (805) 222 6941 | HVAC | Moorpark · Ventura County | — | — |
| 1st Response Plumbing & Flood Damage | Robert Damien Cervantes | jared@1stresponseplumbing.com | (858) 203 0930 | HVAC | National City · San Diego County | — | — |
| 1st Team Air Conditioning INC | Brad Webb Daniels | — | (951) 698 7007 | HVAC | Murrieta · Riverside County | — | — |
| 2 Elements Heating & A/c | 2 Elements Heating & A/c | — | (562) 412 3238 | HVAC | Hacienda Heights · Los Angeles County | — | — |
| 20 / 20 Plumbing & Heating INC | Charles Conaway Iii Cockey | — | (951) 396 2020 | HVAC | Riverside · Riverside County | — | — |
| 2020 Heating & Air INC | Silvia Eufrosina Olivares Montiel | — | (408) 661 9138 | HVAC | San Jose · Santa Clara County | — | — |
| 20th Century Air INC | Scott Robert Baker | — | (714) 450 5060 | HVAC | Murrieta · Riverside County | — | — |
| 21st Century Air Master H V A C INC | Seyed Fakhridden Alemi | — | (949) 444 8889 | HVAC | Aliso Viejo · Orange County | — | — |
| 23 1/2 Hour Home Services INC | Kelly Michael Russum | — | (760) 327 8718 | HVAC | Palm Springs · Riverside County | — | — |
| 24 - Hour Express Services INC | Michael Lee Weimann | — | (951) 302 5320 | HVAC | Murrieta · Riverside County | — | — |
| 24 Seven | 24 Seven | — | (626) 926 6123 | HVAC | Huntington Beach · Orange County | — | — |
| 24/7 Comfort Cooling & Heating | 24/7 Comfort Cooling & Heating | — | (909) 262 0267 | HVAC | Jurupa Valley · Riverside County | — | — |
| 24/7 Drain Rooter INC | James Norman Padgett | interested@domainmarket.com | (619) 303 3575 | HVAC | El Cajon · San Diego County | — | — |