Best Licensed HVAC Contractors in Castro Valley, CA
9 HVAC contractors registered in Castro Valley hold current CSLB licenses, verified against official records as of August 17, 2026. The 8 below are the top-ranked, ordered by years licensed.
- 273 active C-20 heating and air conditioning licenses in Alameda County; 9 registered in Castro Valley
- California requires workers' compensation cover for C-20 licensees: 7 of Castro Valley's 9 licenses (77.8%) carry a current policy with CSLB
- Median time licensed in Castro Valley: 8 years
- Longest Castro Valley licensure: since 1967
- 20 county licenses reach their expiration date within 90 days
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- Verified
- August 17, 2026
- Licensed since
- 1967
- Expires
- 2028-05-31
- Phone
- (510) 582-0934
- Verified
- August 17, 2026
- Licensed since
- 1997
- Expires
- 2027-10-31
- Phone
- (510) 886-5853
- Verified
- August 17, 2026
- Licensed since
- 2008
- Expires
- 2028-01-31
- Phone
- (510) 825-5079
- Verified
- August 17, 2026
- Licensed since
- 2011
- Expires
- 2028-05-31
- Phone
- (510) 886-3112
- Verified
- August 17, 2026
- Licensed since
- 2018
- Expires
- 2028-02-29
- Phone
- (415) 806-3856
- Verified
- August 17, 2026
- Licensed since
- 2024
- Expires
- 2026-11-30
- Phone
- (650) 868-7766
- Verified
- August 17, 2026
- Licensed since
- 2024
- Expires
- 2026-12-31
- Phone
- (415) 579-4129
- Verified
- August 17, 2026
- Licensed since
- 2025
- Expires
- 2027-06-30
- Phone
- (855) 202-9264
Compare the top 6 at a glance
| Company | License | Workers' comp | Licensed since |
|---|---|---|---|
| Frank Bonetti Plumbing Inc. | #251165 | Exempt or none on file | 1967 |
| Specialized Heating & Air Conditioning | #741785 | On file | 1997 |
| Affordable Heating And Air Conditioning | #909632 | Exempt or none on file | 2008 |
| 4-seasons Heating & Air Conditioning | #962971 | On file | 2011 |
| Cheng's Mechanical Contractor | #1036153 | On file | 2018 |
| Sigma Hvac & Electric Inc. | #1128583 | On file | 2024 |
Alameda County HVAC licensure at a glance
California licenses contractors by classification and CSLB publishes one on every record, so supply can be counted exactly: 273 active C-20 heating and air conditioning licenses in Alameda County, 9 of them registered in Castro Valley. CSLB also publishes a real original issue date, which Washington's registry does not, so tenure is measurable here: the median Castro Valley license has been held 8 years, and the longest-standing one dates to 1967. California law requires workers' compensation cover for C-20 licensees, so it is a legal baseline rather than a way to tell two contractors apart: 7 of Castro Valley's 9 licenses (77.8%) carry a current policy in CSLB's file, and we do not rank on it. The contractor bond is not a signal here: 273 of the county's 273 licenses carry the same $25,000 bond California sets by statute. 20 county licenses reach their expiration date within the next 90 days. CSLB cannot link straight to a license record, so every listing above shows its number for you to type into CSLB's license lookup. How we verify.
HVAC Contractors in Castro Valley: common questions
How many licensed HVAC contractors are there in Castro Valley?
9 active C-20 heating and air conditioning licenses are registered in Castro Valley, out of 273 across Alameda County. 9 Castro Valley-registered companies passed our license verification, and the 8 on this page are the top-ranked of those. Only licenses CSLB shows as CLEAR and unexpired are listed.
Does California license HVAC contractors?
Yes. California licenses contractors by classification, and C-20 is the CSLB classification that authorises this work. 9 active C-20 heating and air conditioning licenses are registered in Castro Valley and 273 across Alameda County, the longest-standing issued in 1967. Only CLEAR, unexpired licenses appear here.
How do I check an HVAC contractor's license in California?
Every listing above shows its CSLB license number. CSLB cannot link straight to a record, so open its license lookup and type the number in: it shows status, expiration, the contractor bond and workers' compensation cover, which California requires of C-20 licensees and 7 of Castro Valley's 9 currently carry. 20 Alameda County licenses expire within 90 days.