Duff Mechanical Services

Based in Aguanga, Riverside County, Duff Mechanical Services holds California contractor license #1109379, classified C20 (Warm-Air Heating, Ventilating and Air-Conditioning). The license was active and clear when this listing was compiled.

HVAC contractors carry the C-20 classification, which covers equipment replacement, duct systems, and the airflow and combustion venting that make them work safely.

Working in southwest Riverside County: This corridor has grown fast, so the housing stock ranges from 1970s tract homes to work finished last year — and the two need very different approaches.

Before you hire any hvac or air conditioning contractor: Ask whether the duct system is being tested. California’s Title 24 energy code requires duct leakage testing on many change-outs, and leaky ducts waste a large share of what the equipment produces.

License status can change at any time. Confirm license #1109379 is current, and check bond and workers’ compensation coverage, using the CSLB license lookup before signing a contract or paying a deposit.

This profile was compiled from California State License Board public records and is unclaimed — Duff Mechanical Services has not added its own details. Are you the owner? Claim this listing to add photos, services and a description of your work, or contact us to have it removed.