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Dinelli Plumbing vs Maz Plumbing Under Ground And Sewer Services
San Mateo Plumbing Contractors Comparison · Updated March 2026
Established veteran contractor with full insurance versus newer business with strong owner involvement but no workers comp coverage.
| Dinelli Plumbing | Maz Plumbing Under Ground And Sewer Services | |
|---|---|---|
| Rating | ★ 4.5 | ★ 5.0 |
| Years Licensed | 24 years | 2 years |
| License # | 801472 | 1111601 |
| Workers' Comp | ✓ Yes | — |
| Bond Amount | $25,000 | $25,000 |
| Location | Foster City, CA | San Mateo, CA |
| Website | www.dinelliplumbing.com | mazplumbing.com |
Key Differences
What Customers Say
Dinelli Plumbing
Customers emphasize Dinelli's efficient work completion and honest approach that repairs rather than replaces when possible, suggesting a no-pressure service philosophy.
Maz Plumbing Under Ground And Sewer Services
Maz receives consistent praise for rapid emergency response, transparent upfront pricing, clean worksites, and the owner's direct hands-on involvement across diverse project types.
Key Takeaway: Maz's reviews emphasize speed and accessibility with same-day service and owner availability, while Dinelli's feedback focuses on integrity and straightforward problem-solving without upselling.
Customer Reviews
Dinelli Plumbing
Great sub contractor!! They just get it done and are very professional.
Great plumber,repaired the old valve instead of upselling a new one
Maz Plumbing Under Ground And Sewer Services
Fantastic experience with Al - quality work and great service! Al did an excellent job installing my new bathtub, shower kit, valves, and bath spout. His workmanship is top-notch, everything looks and...
Maz plumbing is SUPERB. Family owned (the actual owner, Al, comes in to do the work with his helper), he has been in business for almost 30 years. Top quality, speed, clear communication, honest, tid...
Al is the only plumber you need to know around this area. I have hired many plumbing companies before I got to know Al and hated all of them so much. Especially big plumbing companies that send out am...
Consider Dinelli Plumbing if...
- ✓ You want full liability protection with workers compensation insurance covering any on-site injuries, eliminating risk to your homeowner's policy
- ✓ Your project may involve hidden complications like older plumbing systems where 24 years of diagnostic experience matters for anticipating problems
- ✓ You prefer an established contractor with proven business systems and two decades of consistent operations in the Bay Area market
- ✓ You value straightforward service without pressure to replace components that can be effectively repaired
Consider Maz Plumbing Under Ground And Sewer Services if...
- ✓ You need emergency or same-day service and value rapid response times, including weekend availability
- ✓ You specifically want the business owner directly performing your work rather than sending crews
- ✓ Your project involves specialized work like underground plumbing, sewer line replacement, or tankless water heater installation where reviews show strong expertise
- ✓ You're willing to verify your homeowner's insurance covers contractor injuries and accept the workers comp gap for the benefits of owner-direct service
Questions to Ask Before Hiring
- → For Maz Plumbing: Ask directly about liability coverage and confirm with your homeowner's insurance whether contractor injuries are covered on your policy, and what your deductible would be
- → For Maz Plumbing: Given the 2-year license, ask for references from projects similar in scope to yours, particularly if your work involves complex diagnostics or older plumbing systems
- → For both: Ask whether the owner or crew members will be on-site, and how they handle unexpected complications that arise mid-project
- → For both: Request a detailed written estimate before work begins, including what's covered if hidden damage is discovered during the project
The Bottom Line
If liability protection and established operational history are priorities, Dinelli Plumbing's 24 years of licensing and workers comp coverage provide clear advantages, particularly for complex projects or older homes. If you need rapid emergency response and value having the business owner directly perform your work, Maz Plumbing's service model is compelling—but only if you verify your homeowner's insurance covers contractor injuries or you're comfortable accepting that risk. For routine work without time pressure, Dinelli's complete insurance coverage and proven track record make it the safer choice for most homeowners.
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Frequently Asked Questions
Yes, it matters for any job where workers enter your property. If someone is injured—even on a quick repair—you could face medical bills and lost wage claims without workers comp coverage. Check your homeowner's policy to see if contractor injuries are covered, but many policies exclude this or have high deductibles. For larger projects with multiple workers or extended timelines, the risk increases substantially.
The 2-year license reflects when the current business was formally established, not the owner's personal experience level. Reviews consistently mention the owner's technical expertise and problem-solving ability across various projects. However, newer licensing means less track record for business practices like warranty follow-through, crew management on larger jobs, and handling project complications that require pulling permits or coordinating inspections.
Maz Plumbing has a clear pattern of same-day and emergency response, with reviews specifically praising sewer line replacement and underground work expertise. Dinelli's reviews don't emphasize emergency availability. If you're facing an active backup or urgent situation, Maz's documented rapid response times and sewer specialization make it the stronger choice, though you'll need to address the workers comp gap.
For straightforward repairs or installations in newer homes, the experience gap may not materially affect outcomes. However, if your plumbing system is older, if you're dealing with potential code compliance issues, or if there's risk of hidden damage behind walls or underground, 24 years of pattern recognition helps diagnose problems before they escalate. Dinelli's longevity also suggests established relationships with inspectors and suppliers that can smooth permitting and material sourcing.
Looking for the Best?
See our ranked list of top plumbing contractors in San Mateo.
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How We Compare Contractors
License Verification
All license data is sourced from official California CSLB records and verified regularly.
Review Analysis
Customer reviews are aggregated from Google and analyzed to identify patterns in service quality.
Detailed Comparison
We analyze credentials, insurance, experience, and feedback to highlight meaningful differences.
Not all licensed contractors are created equal. While a valid license is the baseline requirement in California, contractors can vary significantly in experience, insurance coverage, and customer satisfaction.
- Experience matters: A contractor with 15+ years of experience has likely encountered and solved problems that newer contractors haven't faced yet.
- Workers' compensation protects you: If a contractor without workers' comp insurance has an employee injured on your property, you could be held liable.
- Reviews reveal patterns: Individual reviews can be misleading, but patterns across many reviews often reveal a contractor's true strengths and weaknesses.
- Bond amounts vary: A contractor's bond provides financial protection if they fail to complete work as agreed. Higher bonds offer more protection.
Taking time to compare contractors on these factors can save you from costly mistakes and help ensure your project is completed by a qualified professional.
Data Sources: License information from California CSLB. Ratings and reviews from Google. Last verified March 12, 2026.
This comparison is based on publicly available information. We recommend getting multiple quotes and verifying all credentials directly before hiring.
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