Mahon Plumbing, Inc.
Independent Annapolis-market profile explicitly lists backwater-valve installation, and city records independently show Gregory Mahon performing permitted backflow work in Annapolis.
Who runs it
- Gregory P. Mahon ✓ President; licensed plumber named in Annapolis permit records
Credentials & verification
- State license
- 11839, unverified, re-check with board
- BBB
- A+; not BBB accredited
- Years in business
- 31
Services
Service area
Annapolis · Anne Arundel County · Baltimore · Baltimore City · Baltimore County · Howard County
Reviews (per platform, unblended)
Our verification notes
License 11839 is a Maryland plumbing-board license, not an MHIC number. Backwater valves mitigate sewer backup rather than tidal water entering doors, walls, or foundations. Confirm that the proposed device is a normally open sanitary backwater valve, not merely a potable-water backflow preventer, and require a permit where applicable.
Sources checked
- BBB Business Profile and state plumbing license record
- City of Annapolis plumbing and backflow permit report
- Maryland on-site wastewater professional registry
- Expertise.com Annapolis plumber review and service comparison
Last verified 2026-07-16. This is an independent listing, not an endorsement, and we are not affiliated with Mahon Plumbing, Inc.. Confirm the current license, insurance and references directly before signing any contract.