O’Neill Bros. Plumbing, Rockville, MD: Backflow Testing

Approvals

✓ On the City of Rockville list Phone matches its Google profile

City of Rockville certified backflow prevention testers, as of July 17, 2026. Being on this list means the utility lets the company file backflow test reports in its water system; it is not a state license.

Ask for the certificate number of the tester who will do your test, and check that your own water utility accepts reports from this company.

Call (301) 605-5415 Visit website More testers in Maryland

Price reports

What a backflow test costs in Rockville

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Published prices nationwide

$29.99 to $100 per assembly

$0$25$50$75$100$125

Based on 14 published prices · Read Oct 2026 Prices testing businesses list on their own websites, from our cost guide. Listed prices, not what people paid.

Every published price, with its source: what a backflow test costs.

Failed test? Published repair, rebuild and replacement prices: what a backflow repair or replacement costs.

What O’Neill Bros. Plumbing's website says

Services listed on O’Neill Bros. Plumbing's website, read October 11, 2026: general plumbing, water heaters and drain and sewer service. oneillbrosplumbing.com

Read on oneillbrosplumbing.com on October 11, 2026 (3 pages). This is what the business says about itself.

Where you will find O’Neill Bros. Plumbing

These are the city pages close enough for this business to appear on.

Other backflow testers nearby

Business	Services	Distance
Sky Plumbing	Backflow Testing	under 1 mi
Leahy Plumbing & Heating, Inc.	Backflow Testing	under 1 mi
A Tasker Inc, T/A Salco Mechanical Contractors	Backflow Testing	2 mi
Nick DiBattista Plumbing & Heating, Inc.	Backflow Testing	3 mi
Acker & Sons, Inc	Backflow Testing	3 mi
Shapiro & Duncan, Inc.	Backflow Testing	3 mi

Questions about O’Neill Bros. Plumbing

Is O’Neill Bros. Plumbing approved to test backflow assemblies?

O’Neill Bros. Plumbing is on the City of Rockville list, as of July 17, 2026. That means the utility lets the company file backflow test reports in its system; it is not a state license. Ask for the tester's certificate number before the test.

What does O’Neill Bros. Plumbing do?

Their listing covers backflow testing. Call to confirm the service you need, because offerings change.

What areas does O’Neill Bros. Plumbing serve?

They are based in Rockville, Maryland, within driving distance of Rockville, Silver Spring, Gaithersburg, Washington, Beltsville. Service areas are set by the business, so confirm yours when you call.

How do I reach O’Neill Bros. Plumbing?

Call (301) 605-5415. Their website is linked on this page.

Compiled from public records and public business information. Not an endorsement. Check licensing before you hire.

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