Best Licensed Plumbers in Ontario, CA
42 plumbing companies registered in Ontario hold current CSLB licenses, verified against official records as of August 17, 2026. The 8 below are the top-ranked, ordered by workers' compensation cover and years licensed.
- 696 active C-36 plumbing licenses in San Bernardino County; 43 registered in Ontario
- 16 of Ontario's 43 licenses (37.2%) carry current workers' compensation cover, not liability insurance; a blank usually means an owner-operator with no employees
- Median time licensed in Ontario: 11 years
- Longest Ontario licensure: since 1982
- 59 county licenses reach their expiration date within 90 days
We earn a fee when you call businesses through numbers on this site. This never affects who is listed or how they rank.
- Verified
- August 17, 2026
- Licensed since
- 1982
- Phone
- (909) 947-4601
- Verified
- August 17, 2026
- Licensed since
- 1988
- Phone
- (909) 595-9434
- Verified
- August 17, 2026
- Licensed since
- 1990
- Phone
- (909) 785-5075
- Verified
- August 17, 2026
- Licensed since
- 1990
- Phone
- (909) 391-4646
- Verified
- August 17, 2026
- Licensed since
- 1999
- Phone
- (909) 917-9707
- Verified
- August 17, 2026
- Licensed since
- 2005
- Phone
- (909) 930-5522
- Verified
- August 17, 2026
- Licensed since
- 2008
- Phone
- (909) 969-6044
- Verified
- August 17, 2026
- Licensed since
- 2015
- Phone
- (323) 378-0109
Compare the top 6 at a glance
| Company | License | Workers' comp | Licensed since |
|---|---|---|---|
| Spec Construction Co Inc. | #419626 | On file | 1982 |
| P V & C Plumbing And Piping Inc. | #529259 | On file | 1988 |
| Inter-city Energy Systems Inc. | #587709 | On file | 1990 |
| Fairchild Plumbing & Mechanical Inc. | #606705 | On file | 1990 |
| G & S Reasonable Plumbing / All Tech | #764181 | On file | 1999 |
| Flow Dynamics Inc. | #858166 | On file | 2005 |
San Bernardino County plumbing licensure at a glance
California licenses contractors by classification and CSLB publishes one on every record, so supply can be counted exactly: 696 active C-36 plumbing licenses in San Bernardino County, 43 of them registered in Ontario. CSLB also publishes a real original issue date, which Washington's registry does not, so tenure is measurable here: the median Ontario license has been held 11 years, and the longest-standing one dates to 1982. 16 of Ontario's 43 licenses (37.2%) carry current workers' compensation cover in CSLB's file. That is employee injury cover, not liability insurance, and a blank usually means an owner-operator with no employees - lawful, and not a mark against anyone. The contractor bond is not a signal here: 696 of the county's 696 licenses carry the same $25,000 bond California sets by statute. 59 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.
Plumbers in Ontario: common questions
How many licensed plumbers are there in Ontario?
43 active C-36 plumbing licenses are registered in Ontario, out of 696 across San Bernardino County. 42 Ontario-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 plumbers?
Yes. California licenses contractors by classification, and C-36 is the CSLB classification that authorises this work. 43 active C-36 plumbing licenses are registered in Ontario and 696 across San Bernardino County, the longest-standing issued in 1982. Only CLEAR, unexpired licenses appear here.
How do I check a plumber'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 16 of Ontario's 43 currently carry. 59 San Bernardino County licenses expire within 90 days.