Duff Mechanical Services, C-20 HVAC Contractor in Aguanga, CA
Duff Mechanical Services operating as a sole owner holds an active California contractor license (CSLB #1109379), valid through Aug 31, 2027. First issued in 2023, the license has been on the CSLB roster for 3 years. It carries a single CSLB classification: C-20 — HVAC Contractor. Records show an active surety bond on file with North River Insurance Company (the) and a previously-filed workers' compensation policy with Clear Spring Property and Casualty Company that is no longer active. The business is based in Aguanga, in Riverside County, California.
- License Number
- 1109379
- Issued
- Aug 28, 2023
- Status
- CLEAR
- Expires
- Aug 31, 2027
- Entity
- Sole Owner
- Surety
- North River Insurance Company (the)
- Bond Number
- 04CF645918
- Effective
- Aug 15, 2025
- Status
- Active
- Coverage
- Workers' Compensation Insurance
- Carrier
- Clear Spring Property and Casualty Company
- Policy Number
- CWC03597800
- Effective
- Sep 30, 2025
- Expires
- Sep 9, 2026
This contractor has a compliance issue in its public CSLB record:
- No active workers' comp on file
An automated summary of public CSLB data, not a credit score, rating, or endorsement. How we determine this
Is Duff Mechanical Services licensed in California?
Yes. Duff Mechanical Services holds California Contractors State License Board license number 1109379, which is active and in good standing. The license was first issued on August 28, 2023. It is valid through August 31, 2027.
What does Duff Mechanical Services specialize in?
Duff Mechanical Services is licensed for one CSLB classification: C-20 HVAC Contractor.
Where is Duff Mechanical Services headquartered?
Duff Mechanical Services is headquartered at 53815 Robin Ln, Aguanga, CA 92536, in Riverside County, California.
Does Duff Mechanical Services have an active surety bond on file with CSLB?
Yes. Duff Mechanical Services has an active California contractor surety bond filed with North River Insurance Company (the).
Does Duff Mechanical Services carry workers' compensation coverage?
Duff Mechanical Services has a previously-filed workers' compensation policy with Clear Spring Property and Casualty Company that is no longer active.
How do I verify Duff Mechanical Services's contractor license?
You can verify Duff Mechanical Services's license directly with the California Contractors State License Board at https://www.cslb.ca.gov/OnlineServices/CheckLicenseII/LicenseDetail.aspx?LicNum=1109379.
- License issuedAug 28, 2023
- Bond activeAug 15, 2025
- WC coverage startsSep 30, 2025
- WC expiredSep 9, 2026
- License expiresAug 31, 2027
- First Choice Plumbing Heating & Air Conditioning INC#260795Riverside·B General Building Contractor
- Amber Air Conditioning Company#319072Lake Elsinore·C-20 HVAC Contractor
- Watson Company#299810La Quinta·B General Building Contractor
- Desert Air Conditioning INC#276586Palm Springs·C-20 HVAC Contractor
- Comfy Home#379530Calimesa·C-20 HVAC Contractor
- Larby Cole Mathew#382403Palm Desert·B General Building Contractor
- Dzikowski Ted S#381054Hemet·B General Building Contractor
- Palm Desert Air Conditioning Company#374937Palm Desert·C-20 HVAC Contractor
Working a California job with Duff Mechanical Services, or chasing an unpaid invoice? These free tools track your mechanics lien deadlines and rights under California Civil Code §§8200–8848.
- California preliminary notice deadline calculatorFind your 20-day deadline and the lien rights at risk.
- Do I need a preliminary notice in California?Answer a few questions to see if the 20-day notice applies.
- Did I lose my California lien rights?Check whether your mechanics lien window has passed.
- Unpaid construction invoice in CaliforniaYour options and deadlines for collecting on a California job.
Own Duff Mechanical Services? Claim or correct this profile