Backflow Testing and Prevention in Lancaster, PA

What is a backflow preventer?

A backflow preventer is a valve assembly on the water service that stops water from flowing backward into the public supply when pressure drops.

Businesses, irrigation systems and fire sprinkler lines carry backflow preventers, and water utilities require a yearly test by a certified tester.

What are the 4 reasons to test a backflow preventer?

The 4 reasons to test a backflow preventer are listed below.

• The water utility sends a yearly test notice.
• A new backflow preventer is installed.
• The backflow preventer leaks or drips from the relief port.
• A building changes use or adds an irrigation or fire line.

How does a plumber test a backflow preventer?

A certified plumber uses the 4 steps below to test a backflow preventer.

1. Connects a test kit to the test cocks.
2. Measures the pressure drop across each check valve.
3. Repairs or rebuilds a check valve that fails.
4. Files the test report with the water utility.

How much does backflow testing cost in Lancaster, PA?

Backflow testing in Lancaster, PA costs up to $350 a year, and a new backflow preventer costs $150–$450 to install, according to HomeAdvisor. The backflow cost depends on the device size and the number of devices.

Typical prices for 3 backflow testing jobs are shown in the table below.

Source: HomeAdvisor national cost data, 2025–2026. Ranges are what most homeowners pay; your plumber gives the price for your job before work starts.

Related plumbing problems and next steps

When is a backflow testing problem an emergency?

A backflow testing problem is an emergency when the relief port discharges water constantly. Call a certified tester for a repair. Emergency calls for water line problems go to an emergency plumber in the Lancaster area.

What services are related to backflow testing?

The 3 services related to backflow testing are listed below.

• Water line repair is the parent service, and the water line repair in Lancaster, PA page covers it in full.
• Pressure reducing valve signs, steps and prices are on the pressure reducing valve in Lancaster page.
• Low water pressure plumber signs, steps and prices are on the low water pressure plumber in Lancaster page.

Frequently asked questions

Written and fact-checked by the Lancaster PA Plumbers editorial team. Prices are national ranges from HomeAdvisor cost data; the plumber you speak with prices your job before work starts. Last updated October 29, 2026.