Home / License lookup / California / San Diego Boiler
California contractor license
San Diego Boiler
San Diego Boiler of San Diego holds California license 1136130 (C4 Boiler, Hot Water Heating and Steam Fitting). The CSLB file dated Nov 1, 2026 lists it as active.1 It expires Apr 30, 2027.
Active
San Diego Boiler, San Diego
- License
- 1136130
- Class
- C4 Boiler, Hot Water Heating and Steam Fitting
- Expires
- Apr 30, 2027
- Bond
- $25,000
- Workers' comp
- Insured to Jul 30, 2027
CSLB file dated Nov 1, 2026
From the CSLB file dated Nov 1, 2026. Not a consumer report; check the board before you hire.
Has the board taken action on this license?
None in the CSLB file dated Nov 1, 2026. Confirm with the board: CSLB license check
What bond, insurance and workers' comp are on file?
- Bond
- $25,000Merchants Bonding Company (Mutual), from Apr 3, 2025, continuous
- Liability insurance
- Not in the CSLB fileCheck with the board
- Workers' comp
- InsuredWellfleet Insurance Company, from Jul 30, 2026, to Jul 30, 2027
Who is on this license?
- Responsible managing officer, CEO and president
- Mario A. Frayre CastilloSince Apr 17, 2025
What work does this license cover?
Issued Apr 17, 2025.
Which other San Diego businesses hold C4 Boiler, Hot Water Heating and Steam Fitting?
- County Burner And Machinery CorpLicensed since 1976
- National Air & EnergyLicensed since 1995
- JK Morgan CompanyLicensed since 2008
- San Diego Backflow TestingLicensed since 2019
- Aerco Systems LLCLicensed since 2021
What should you check before hiring?
What to ask before you hire
- Get the license number in writing. The name on the license should match the name on your contract and invoice.
- Check the class covers the job. A license for one trade doesn't cover another. California license classes
- Ask for a certificate of insurance sent to you by the insurance agent, not handed over by the contractor. How to read a COI
- Ask who will be on site. If a crew works on your property, ask for proof of workers' comp. An exemption on file means the contractor told the CSLB it has no employees.
- Put it in a written contract: license number, price, start date and payment schedule. Check the license again on the day you sign.
If the license is lapsed
- Don't sign or pay a deposit until the CSLB shows the license active again.
- Ask the contractor why. For a bond or insurance lapse, ask for proof that the new bond or policy was filed with the CSLB, then check again.
- If work has started, hold further payments, keep the contract, receipts and photos, and file a complaint with Contractors State License Board (CSLB).
- Check another contractor. California license lookup
Sources
- CSLB License Master (cslb.ca.gov, Nov 1, 2026)
- Contractors State License Board (CSLB)