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Backflow testing in Centreville, from Sully Station to Centre Ridge: the yearly Fairfax County test, and a fix priced in writing if the device fails.
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Our plumbing team in front of three of our vans.
Licensed and insuredVirginia Class A contractor #2705192276
24/7 emergency serviceOften same-day, and we will tell you honestly when we can get there.
Our own plumbers, our own trucksNobody here is a subcontractor with a magnet on the door
The price is settled before the workYou see the number in writing before anything is taken apart
What it costs
How many devices you have and what kind they are decide the number, so there isn’t one figure that fits every house. You get one flat price per device when you book, before anyone comes out.
Yearly backflow test
One flat price per device, given when you book
Repair or rebuild after a failed test
Priced in writing before any work
New backflow preventer, installed
Priced in writing before any work
A device that fails is priced in writing before any work. Most can be rebuilt with new springs, seats or rubber parts; a body cracked by a freeze gets replaced. Either way it’s tested again afterward, which Virginia requires.
The national numbers, and what moves a price up or down, are in our backflow testing cost guide.
What’s different in Centreville
About seven Centreville homes in ten went up between 1980 and 1999, and builders of that era often left the lawn sprinklers out, so a system here was usually added later by an owner. Fairfax County says many older systems went in after the house was occupied, without a permit, and likely never had a final inspection. If yours came with the house you bought, nobody may know whether the device on it was ever the right one.
The County doesn’t grandfather them. A testable device on in-ground lawn sprinklers has been in Virginia’s building code since the early 1970s, so a 1990s system answers to the same rule as last year’s. The most common miss the County names is a dual check: it looks the part and gives some protection, but it can’t be tested, and the County encourages owners to swap it for an assembly that can. In Fairfax County that swap takes a plumbing permit, and so does any replacement, even like for like. The rest of the program is on our Fairfax County backflow page.
Shutting the sprinklers off doesn’t take you off the list. The County wants every testable assembly tested whether it’s in use or not. If the system is truly finished, there’s a proper way out: email the County’s Cross Connection Program at LDSCrossConnectionProgram@fairfaxcounty.gov with your address and the Record ID, take the device off and disconnect the line, and a County inspector verifies it. A simple removal can be checked from before and after photos, and that step needs no permit.
About six homes in ten here are townhouses or in condo buildings. In a condo building with fire sprinklers, the line feeding them has its own backflow assembly, and the County tracks fire suppression right beside lawn sprinklers. That device, like the sprinklers on the common grounds, is normally the association’s to book. A townhouse owner who added a system in the back yard is the exception: that notice is yours. Managers with a whole list of devices can start at commercial backflow testing.
By the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
When it’s time
Fairfax Water’s backflow postcards and newsletters point to the same County program as the yearly notice. Not sure what’s protecting the line to your sprinklers, pool or hot tub? The County will send someone out to look at no charge.
A letter from the water utility with a date on it means there’s a testable device on your line, usually on the lawn sprinklers, and its test is due.
On an RPZ, a little water when the pressure jumps can be normal. A steady stream from the opening underneath means a check valve isn’t sealing, and it won’t pass.
Before the first hard freeze
A device that sits full of water all winter is the most common reason it fails the spring test. Around here, get this done by the end of October.
On most houses it’s outside by the foundation: a brass valve on two pipes standing out of the ground, with a cap on top. That’s a PVB. An RPZ or double check may sit in a basement or a box in the ground instead.
Turn off the valve that feeds the sprinklers, usually in the basement or utility room just past the main shutoff. Leave the rest of the house on.
Most systems here get blown out with compressed air so nothing sits in the lines or the device. If yours hasn’t been, that’s the step that matters.
Set the device’s two shutoff handles and its little test cocks about halfway, near 45 degrees, so no pocket of water stays trapped inside to freeze.
An insulated cover helps a PVB through the winter. On an RPZ, never block the relief valve opening underneath: it has to be able to dump water.
Some owners bring the device inside for the winter. Check the rules first: Loudoun Water wants a device that came off tested again when it goes back on, and Fairfax County wants it back on before your testing month.
Not sure it was drained, or saw water coming from the cap when the sprinklers ran? Call us. We’ll look at it, and if it cracked, you get the reason and a price before anything gets replaced.
Who sends the notice
Fairfax County’s Cross Connection Program wants testable backflow devices on lawn sprinklers, fire sprinklers, pools and hot tubs tested every year by a tester on the County’s Authorized Vendor List. The tester files the report and the County emails you when it’s in; nothing after 14 days, and the County asks you to check with them. Source.
Each property gets its own testing month from the County’s tax map grid, and the report is due before that month ends. A device that fails has to be repaired or replaced and retested within 10 business days of the failed test, and one taken off for the winter goes back on before the testing month. Source.
Our Virginia Class A contractor license, 2705192276, is on the side of the van.
Choosing a tester
Questions to ask anybody who offers to test it, us included.
Fairfax County won’t take a partial report, so a house with sprinklers and a pool, or two devices on one system, needs every one tested and on the report. Count what the notice lists and make sure the quote counts the same.
Since January 1, 2023, Virginia only accepts tests from a DPOR-certified Backflow Prevention Device Worker, and some places keep a list of their own on top. Ask to see the certificate before the gauge goes on.
Some utilities take it from the tester and some want it from you. Ask which, and keep a copy either way, so you can show the date if a second notice turns up.
Ask for the reason and a written price before anything gets taken apart, and whether the retest is part of it. A failed device runs on a deadline, so a tester who can also fix it saves you a second trip.
Two of our crew going over a work order before the day's calls.
From our Google reviews
5.0 stars across 1,131 reviews. Read them on our reviews page.
Zabi helped us with a complex plumbing problem. He explained clearly the problem and gave us various repair options. He is courteous, professional and highly experienced. We recommend him!
Where we work
Next door to Centreville: Chantilly, Manassas, Fairfax, Bristow and Gainesville.
Questions
Yes, as long as the device is still connected to the water line. The way out is removal: take it off, disconnect the line and have a County inspector verify it, which updates your record.
It comes from noreply@workflownotification.com, which is easy to mistake for junk, and the County itself says to check the spam folder for it. That email is your proof the report went in, so keep it with the house papers.
One flat price per device, given when you book, before anyone comes out. How many devices you have, and whether one needs a repair, is what moves it. Our cost guide has the national numbers.
About 30 minutes a device. The water is off for a few of those minutes while the gauge readings are taken.
Ready when you are
Call, or send the form at the top. Have the notice handy: how many devices it lists and the date on it are what we need.
SwiftPro Heating, Cooling & Plumbing
4230 Lafayette Center Dr N, Chantilly, VA 20151
44679 Endicott Dr, Suite 211, Ashburn, VA 20147
Virginia Class A contractor license #2705192276
SwiftPro Heating, Cooling & Plumbing is a licensed, BBB Accredited (A rating), independently owned heating, cooling and plumbing company in Chantilly, serving Centreville and the rest of Northern Virginia. Virginia contractor license #2705192276. 5.0 stars across 1,131 reviews on Google, Angi, Yelp, the BBB and Facebook. SwiftPro maintains a dedicated HVAC team and a dedicated plumbing team.
From SwiftPro Heating, Cooling & Plumbing in Chantilly. Housing figures are the Census Bureau’s American Community Survey, 2020 to 2024, for each place named; permit, water and sewer facts link to each office’s own page and were checked in September and October 2026.