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Backflow Testing · Clarksburg, MD

Backflow Testing, Installation & Repair

Safe water, fully compliant.

If your business’s backflow preventer is not working, it is a problem, for your safety and your compliance. We test, install, and repair backflow assemblies of all makes and sizes for restaurants, rentals, offices, and properties across Clarksburg and Montgomery County, send annual reminders, and submit your results so you do not have to worry about a thing.

Certified TestingLicensed & InsuredWe File Results
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Tested & filed
Compliance handled for you
The basics

Why backflow protection matters

A backflow preventer keeps contaminated water from being siphoned backward into the clean water supply, protecting your customers, your staff, and the public. Because lives depend on it, the water authority requires most commercial and irrigation backflow assemblies to be tested every year by a certified tester. We handle the whole process: testing all makes, models, and sizes, repairing or replacing assemblies that fail, installing the right device for new businesses, and submitting the results for you, so you stay safe and compliant without the hassle.

What we do

Backflow services

Testing, repair, installation, and the paperwork, handled by certified pros so you stay compliant.

Backflow Testing

Certified annual testing on all makes, models, and sizes of backflow assemblies, done right and documented.

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Backflow Repair

When an assembly fails, we rebuild or repair it fast so you pass and stay open for business.

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Backflow Installation

For new businesses and builds, we determine and install the right backflow prevention device for your needs.

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Annual Testing & Reminders

We track your due dates and notify you when it is time, so a lapsed test never catches you off guard.

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Test Result Submission

We submit your test results to the water authority for you, so you do not have to worry about a thing.

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Backflow Replacement

Old or failed preventers replaced with a compliant assembly sized correctly for your system.

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How it works

How backflow testing works

We make staying compliant simple, start to finish.

1

Schedule the test

We track your due date and reach out, or come right away when you call.

2

Test the assembly

A certified tester checks your backflow preventer to confirm it is protecting your water.

3

Repair if it fails

If it does not pass, we rebuild, repair, or replace it on the spot when possible.

4

Submit the results

We file the report with the water authority for you, so your compliance is documented.

When to call

When you need backflow service

If any of these apply, it is time to test, repair, or install, and we will keep you compliant.

Your annual test is due

Most commercial and irrigation assemblies must be tested every year. We track it so you never lapse.

You got a notice from the water authority

If you received a testing notice or a non-compliance letter, we handle the test and the paperwork.

You are opening or building a business

New construction and new businesses need the right device selected, installed, and tested.

Your assembly failed a test

A failed backflow test means repair or replacement before you are compliant again.

Discolored or odd-tasting water

Backflow issues can let contaminants into the supply. Get it checked right away.

You added irrigation or equipment

New irrigation, boilers, or equipment often require their own backflow protection.

Test due or got a notice? We'll handle it.

Know your device

Types of backflow preventers

We test, repair, and install every common type, and help you pick the right one for new installs.

RPZ Assembly

Reduced pressure zone assemblies, used for high-hazard applications where protection is critical.

Double Check Valve

Double check valve assemblies, common for lower-hazard commercial and fire line protection.

PVB / Irrigation

Pressure vacuum breakers and irrigation backflow devices that protect against lawn and system contaminants.

Compliance in Maryland

Why this matters here

Across Montgomery County, water authorities require annual backflow testing for most commercial properties and irrigation systems, with results filed on time. Miss it and you risk fines or a shut-off. We track your due dates, test and repair as needed, and submit everything, so compliance is one less thing on your plate.

  • Most commercial and irrigation backflows need annual testing
  • Let us track your due date so a test never lapses
  • Failed assemblies must be repaired or replaced to comply
  • We submit results to the water authority for you
Set it and forget it

Annual reminders

Put your backflow testing on autopilot. We will notify you when it is due and handle the test and filing every year.

Schedule testing
Certified & licensed

A crew you are glad to let in

Backflow testing has to be done by a certified tester, and our own trained, background checked team is exactly that. We test it right, fix what fails, file the paperwork, and keep your business safe and compliant.

From our neighbors

What your neighbors say

4.8
Based on 581 Reviews
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Anna F.
October 28, 2026

John and his assistant, Maddie, replaced a water heater. They did excellent work and were friendly and nice. We were pleased with the work and will contact them at Clarksburg Plumbing for any plumbing needs in the future.

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Quinton W.
October 27, 2026

Very professional team to work with who really cares about client needs

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Jackie S.
October 26, 2026

A terrific, reassuring experience getting me through a broken sewer line emergency which required digging up and replacing 20 ft of cracked, aging sewer line that had a belly. Everyone I worked with at Clarksburg was professional, competent, and efficient. The price was reasonable as well . Special shout out to my excavation crew: Noah, Markell, and Deybis headed by Jason. Thanks to Garrett and Cris who did my initial emergency intervention, snaking and diagnosis, Teyvon, John and Brady who helped with the hydrojetting, camera, and advice on how to prevent recurrence before pipe replacement. On a previous occasion, I had a great experience with Tyler who checked for a toilet leak and caulked. Finally, I greatly appreciated the comforting attention of the excellent reception staff Charlotte and Katie. Much appreciated Clarksburg Plumbing!

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Jan B.
October 23, 2026

Tyler and Brad did a great job replacing my water heater today. They cleaned up afterward and thoroughly checked everything before they left.

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Brandon H.
October 22, 2026

⭐⭐⭐⭐⭐ Tyler from Clarksburg Plumbing did an outstanding job fixing my leaking shower! He was professional, courteous, and communicated clearly throughout the entire process. I really appreciated how he kept me informed and made the experience easy and stress-free. His attention to detail and pride in his work stood out. It’s a great feeling to have someone working in your home who treats the job with care and professionalism. Tyler delivered excellent service, and I would absolutely recommend him and Clarksburg Plumbing. Thank you, Tyler, for a job well done!

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Catherine J.
October 15, 2026

Seth was excellent; he provided great and fast service and was very helpful as the scope of the work increased. Thanks!

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Billie H.
October 13, 2026

Wonderful crew. May God bless them.

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sam S.
October 13, 2026
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Evangeline L.
October 12, 2026

They are great and patience people I love their job.

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Sean P.
October 8, 2026
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Michele M.
October 8, 2026

I had an absolutely wonderful experience with Clarksburg Plumbing LLC, and especially with Seth. From the moment he arrived, he was professional, respectful, knowledgeable, and quite frankly, a breath of fresh air. I was extremely nervous about the situation because my leak was below the main water shutoff valves, and the water had to be turned off at the street. Seth immediately put me at ease and assured me that everything was going to be okay. Rather than just putting together a temporary solution, he wanted to make sure he ordered the exact parts needed to do the job properly. Seth told me he expected to have the correct part and be able to return on Wednesday to complete the repair. On Tuesday afternoon, the office called to let me know the part had arrived and confirmed that Seth would be back Wednesday morning between 8:00 and noon. Seth was at my door at 8:10 AM! I was genuinely impressed. He completed the repair carefully, explained everything he was doing, and was extremely conscientious about properly turning the water back on, opening the faucets in the house, and making sure everything was working exactly as it should. What impressed me most, though, was Seth himself. He has a wonderfully calm, professional demeanor that made a very stressful situation so much easier for me. I sincerely appreciate the care he took with my home and the respect he showed me throughout the entire process. Clarksburg Plumbing is very fortunate to have someone like Seth representing their company. I would absolutely recommend them and Seth!!

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Eric L.
October 7, 2026

Charlie did a fantastic job, would highly recommend.

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Christopher D.
October 5, 2026

Seth did an excellent job!

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Riadh Z.
September 30, 2026

Tyler was great professional and knows what he’s talking about

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Natalie R.
September 29, 2026

I had a great experience with Tyler when he came out to replace our toilet flushing system. From start to finish, Tyler was incredibly courteous, professional, and knowledgeable. He walked me through what needed to be fixed, answered all my questions patiently, and completed the job efficiently. It’s rare to find such high-quality service and attention to detail. Everything is working perfectly now, and he left the work area completely clean. I highly recommend Tyler for any plumbing needs!

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Todd O.
September 28, 2026

Tyler was polite and professional. Satisfied.

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Robert B.
September 25, 2026

John and Maddy showed up on time and did a superb job. Very friendly and informative

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william B.
September 24, 2026
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Pamela B.
September 21, 2026

Absolute best plumbers I have ever used. Needed them a few times recently and each time they were so professional, kind and resolved each problem the first time around. This last issue took them several hours to fix. They explained everything along the way and gave a very fair price for a lot of work. They also work very cleanly! I will never use another plumber! I wanted to add a new review but I could not so I am editing my previous one. I had to use Clarksburg Plumbing again today and like last time, they were exceptional. I was fortunate enough to have John and Madeleine as my service technicians. I will always request them going forward. They are kind, professional and knowledgeable! I am sure the company knows how fortunate they are to have them as part of their team!

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John S.
September 18, 2026

We thank Clarksburg Plumbing again for superior, high quality and friendly service! ----- Clarksburg Plumbing visited us last week to repair an external spigot that had been leaking. The work involved creating a little inside access panel. Within and without, a nice, neat job by Charlie and his understudy apprentice, Chris. Problem solved and happy campers here! ----- UPDATE: Plumber John Brown presented himself on time and got right to work replacing my Mom's ancient leaky kitchen faucet with a new store-bought one that I provided. During the process, Mr. Brown detected and showed me two other problem areas contributing to the water leaks: a cracked drain pipe and then rusted threads on the sink trap. He efficiently and expertly repaired all three elements to our full satisfaction. Plus, John is a super nice guy, completely honest and classy enough to laugh at all my corny jokes! The next time you need any plumbing work in your home or business, I strongly endorse John Brown and anyone on the Clarksburg Plumbing team! UPDATE 2: John and his understudy Maddie visited, and quickly solved the problem of a pinhole leak in copper tubing leading from our hot water heater. He advised us on other plumbing needs, for which we have scheduled and will otherwise follow-up. Thank you Clarksburg Plumbing for your top quality people - John Brown in particular - and performance.

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John H.
September 17, 2026

Their work was excellent. The problem solved a difficult situation with a water pipe leak and worked hard to implement it. Very grareful for the work of Franklin, Noah, Cotton, Markell, Tevon, Jason, Deybis

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G M.
September 16, 2026

Tevon, Noah, Markell, and Morrow were sent by Clarksburg Plumbing LLC to repair an outside broken waterline They arrived at the appointed hour and completed the work in about 3 hours. I was very impressed with them and I would like to recommend all four of these very professional and friendly technicians. Clarksburg Plumbing is a fantastic organization; the office staff, Katie and Charlotte, who helped me are the best.

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Tom F.
September 15, 2026

Our well lines began to leak after many years of service. Noah Zohrabi,YDeybis Gomez & Markel Watts came to the rescue! Excellent service from some very professional, courteous & knowledgeable folks!

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Viannah E.
September 12, 2026

Thank you to Seth, who came on Wednesday and fixed one of our two toilets and fixed our primary bedroom shower. And thank you to Charlie, who came today and replaced our other toilet and replaced our garbage disposal. You are both lifesavers! Our weekend (and going forward) will be MUCH nicer now that we can use our bathrooms (and garbage disposal) again. Highly recommend Clarksburg Plumbing.

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Ms. R.
September 11, 2026

Excellent service today from John Brown and Madeleine S. They were very kind and took time to explain the issue with my dishwasher. I really appreciate their professionalism and efficiency. I would definitely consider using this company again based on my service today!

Good questions

Backflow testing FAQ

What business owners and property managers ask us most about backflow.

A backflow preventer stops contaminated water from flowing backward into the clean water supply. Because it protects public health, the water authority requires most commercial and irrigation assemblies to be tested every year by a certified tester to confirm they still work.

In most of Montgomery County, commercial and irrigation backflow assemblies must be tested annually. We track your due date and remind you, so a lapsed test never catches you off guard.

Yes. We file your backflow test results with the water authority for you, so your compliance is documented and you do not have to worry about a thing.

If an assembly does not pass, we repair or rebuild it, and replace it if needed, then retest so you are compliant. We can often do the repair on the same visit.

Yes. For new businesses and builds, we determine which backflow prevention device your system requires, then install and test it to code.

Often yes. Irrigation systems typically require their own backflow protection and annual testing. We test and service irrigation backflow devices along with your other assemblies.

We serve Clarksburg, Germantown, Gaithersburg, Rockville, Damascus, Potomac, North Bethesda, and the surrounding Montgomery and Frederick County area.

Stay compliant

Let's get you tested.

Let's Flow.

Test due, failed assembly, or a new install? Book online or call a real person. We test, repair, install, and file the results, so your business stays safe and compliant. Here 24/7 for emergencies.

Book online

Let's get started

(301) 972 2223

Available 24/7 for Clarksburg and beyond

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