Backflow preventer testing, repair, and maintenance


Maintaining a backflow prevention system is critical to protecting potable water supplies.

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Contamination of potable water caused by a leak in the backflow prevention system poses a threat to public health.

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Boilers and water heaters require regular maintenance for efficient, cost-effective operation.

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Leaks or breaks in water, gas, or sewer lines must be addressed immediately to avoid endangering public health.

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DSG Backflow Preventer Services

DSG Backflow Preventer Services, specializing in backflow preventer testing, repair, and maintenance in NH and MA

DSG Backflow Preventer Services specializes in the repair and testing of backflow preventers on domestic water systems. Fully licensed and insured, we bring over 25 years' of experience to your job and can provide testing of backflow preventers for the customers of Pennichuck Water Systems and Manchester Water Works. We will work with your schedule and handle delivery of test reports to the responsible agency. The process is easy - you simply need to have the alarms turned off to allow proper closing of the downstream valves and flow test, and we do the rest. For more information, call us today at (603) 235-9645.


The backflow preventer is the most important protection device on the domestic water system. Its primary function is to prevent the reverse flow of water in a system due to an increase in downstream pressure above that of the supply pressure. Mechanical backflow preventers have internal parts that are subject to wear and tear. They must be tested periodically with calibration equipment to ensure proper function. DSG Backflow Preventer Services is licensed to perform all testing, maintenance, and repairs to backflow prevention systems. Call DSG Backflow Preventer Services today at (603) 235-9645 for more information or to schedule an appointment.

Certification & Testing

While testing can be performed by an inspector certified through the New England Water Works Association (NEWWA), repairs and replacement of parts can only be carried out by a licensed plumber. DSG Backflow Preventer Services is licensed in New Hampshire and Massachusetts to perform all necessary repairs and/or replacement of damaged valves and breakers.

NEWWA Certification

New England Water Works Association (NEWWA) Certification is recognized throughout the United States, however some states (such as Massachusetts) require separate certification. DSG Backflow Preventer Services is licensed to perform all backflow prevention system and plumbing repairs in New Hampshire and Massachusetts.