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SwiftPro tests and repairs backflow preventers in Vienna, and the yearly test is $250 a home (normally $300). Call SwiftPro, rated 5.0 stars across 1,130 reviews, at (703) 997-9757, 24 hours a day, 7 days a week.
SwiftPro’s plumbers in Vienna are rated 5.0 stars across 1,130 reviews and work under Virginia Class A contractor license 2705192276. Backflow testing in Vienna, inside the town line or out by Wolf Trap: the test lands in your assigned month and the report goes to Fairfax County. Book it at (703) 997-9757 or online. We’re rated 5.0 stars across 1,130 reviews, and we set the visit around the date on your notice.
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Licensed and insuredVirginia Class A contractor #2705192276
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The price is settled before the workYou see the number in writing before anything is taken apart
What it costs
The yearly test is $250 a home, normally $300, and you can pay for it online. HOA and condo communities that book their units together pay $175 to $225 a unit. A new preventer, installed and tested, runs $800 to $1,200. Those are for a home’s device up to 1 inch; where an HOA unit or a new preventer lands in its range is set at the house and quoted before we start.
Yearly backflow test, one home
$250 (normally $300)
HOA or condo units booked together, per unit
$175 to $225
New backflow preventer, installed and tested
$800 to $1,200
Repair or rebuild after a failed test
Priced in writing before any work
Prices checked .
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.
Booking for an HOA, townhouse or condo community? Here’s what each unit pays when the community books one visit. And what a backflow test costs covers what moves the price up or down.
What’s different in Vienna
Vienna’s program is run day to day by Fairfax County’s cross connection staff, and they work by email. About 60 days before your testing month ends, the due notice goes to the contact on the County’s record, with a paper copy mailed to the house where the device sits. If you bought the place last year, that record may still name the seller, or the irrigation company that put the system in. Fixing that takes five minutes on the County’s cross connections page, and it’s worth doing, because a notice that went to the wrong inbox doesn’t buy you any extra time.
The timing is tighter than it looks. The test counts only inside the 30 days before your due date, so testing early in spring to get it over with doesn’t move your month, and testing after it means you’re late. Book for the window, and if the device fails, the clock for the repair and retest is short, so pick someone who can fix it on the same visit or soon after.
Inside the town line, the median owner’s house dates from 1972, yet about one in four has gone up since 2000, much of it rebuilt on old lots. Those new houses often come with lawn sprinklers and a device by the foundation, which is why a street of 1960s ramblers can have one house getting the letter. Out around Wolf Trap it’s almost all detached homes, a third of them from the 1980s and 90s, on lots big enough that sprinklers were common. And the Town’s water reaches past its own line, to roughly 3,300 connections outside it, so your bill, not your mailing address, tells you who supplies you. Either way the report goes to the same County office.
One thing to know if you’re done with the sprinklers: Fairfax won’t take a report that says the device is not in use. Pulling it off for winter and putting it back is fine. Taking it out for good needs the County’s written approval first, or the notices keep coming. Our Fairfax County backflow page walks through the County program step by step.
Neighborhood by neighborhood
Census figures for the owner-occupied homes in each place, and what usually brings the test notice to houses like these.
| Place | Median home built | Most homes are | Heated with | What usually needs the test |
|---|---|---|---|---|
| Wolf Trap | 1980 | single-family houses, nearly all | gas, about 7 in 10 | Sprinklers added by an owner, pools and hot tubs. |
| Vienna | 1972 | single-family houses, about 8 in 10 | gas, about 8 in 10 | A sprinkler system or pool added later, where there is one. |
By the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
Nearly the whole town sits in 22180, which it shares with county streets toward Dunn Loring and Merrifield.
Vienna mail outside the town line: Wolf Trap and the Tysons edge in 22182, the Oakton side of 22181, Dunn Loring. The figures are Wolf Trap’s, the biggest piece.
When it’s time
In a town where old houses keep getting rebuilt and sold, plenty of owners find out about the device from the first email. If the notice names a system you didn’t know you had, walk the foundation and the basement wall where the water comes in before you call.
Anything piped to the water supply that could push water back into it gets a device: lawn sprinklers, a pool fill line, a hot tub. More yard usually means more of them.
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.
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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
The Town of Vienna runs its program with Fairfax County Cross-Connection Control. Each property with a device gets a testing month, set by its Fairfax tax map grid, and is tested in that month every year. The tester has to be on Fairfax County’s authorized vendor list and files the report with the County within 10 business days; only passing reports count, and the Town can shut off water when a report never arrives. Source.
A new or replacement backflow assembly on a house or townhouse needs a plumbing permit, and so does a lawn irrigation system with its backflow preventer. Source.
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 only counts a passing report filed in the window, and the tester is the one who files it. Ask when it goes in, and ask for a copy of what was submitted, so you can match it against the County’s email when it arrives.
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 1,130 reviews. Read them on our reviews page.
My technician James gave an honest assessment of my situation, clearly laid out the scope of work, and provided different pricing options to resolve my concern. I will definitely call SwiftPro in the future for any plumbing needs!
Where we work
Next door to Vienna: Dunn Loring, Oakton, McLean, Fairfax and Reston.
Questions
No. Whether your water comes from the Town or from Fairfax Water, the test report goes to Fairfax County’s cross connection program and the testing month comes from the County’s tax map grid. What changes is who shuts the water off if a report never shows up.
The County’s health department lists hundreds of permitted wells in 22181 and 22182. The yearly utility notice follows devices on the public water system, so a house drawing only from its own well usually doesn’t get one. If you have both a well and a public connection, call us and we’ll look at how they’re kept apart.
No, but you can. Removing it for winter and reinstalling it in spring needs no approval in Vienna’s program. Just get it back on and tested before your month, and don’t leave it full of water if it stays outside.
SwiftPro does, all over Vienna. We test the backflow preventer on your sprinkler system, fire line or pool in about 30 minutes, repair it on the same visit if it fails, and get the report where your water utility wants it. Call (703) 997-9757 or book online.
The yearly test is $250 a home, normally $300, and you can pay for it online. HOA and condo units booked together on one visit run $175 to $225 a unit. A new preventer, installed and tested, is $800 to $1,200. Where an HOA unit or a new preventer lands in its range is set at the house and quoted before we start, and a device that fails is quoted in writing before any repair. More in what a backflow test costs.
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. Or pay $250 online and we’ll call to pick the day.
SwiftPro Heating, Cooling & Plumbing
4230 Lafayette Center Dr N, Chantilly, VA 20151
44679 Endicott Dr, Suite 211, Ashburn, VA 20147
SwiftPro Plumber & Water Heaters
4200 Lafayette Center Dr, Suite N, Chantilly, VA 20151
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 Vienna and the rest of Northern Virginia. Virginia contractor license #2705192276. 5.0 stars across 1,130 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.