Brown at the hot tap after a flushing round
If the hot water is still tinted a day after FCWSA’s crews have moved on, while the cold side runs clear, the discolored water made it into the tank. Draining the tank clears it.
Marshall, Virginia
Water heater flush in Marshall.
Marshall water heater flushes and tankless descales, on FCWSA’s well-fed mains or a private well. Tank flushes are $99 right now, with a plumbing check.
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- Tank or tankless, any brand
- Priced before we start
- Pay after the visit
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Two of our technicians in a customer’s basement, next to the furnace and a tank water heater.
Licensed and insuredVirginia Class A contractor #2705192276
24/7 emergency serviceOften same-day, and we will tell you honestly when we can get there.
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The price is settled before the workYou see the number in writing before anything is taken apart
What it costs
What a water heater flush costs in Marshall.
Same prices as our water heater flush page, anywhere in Northern Virginia, and you pay after the visit.
Tank water heater flush, with the plumbing check
$99, normally $199
Tankless descale, with the plumbing check
$300, regularly $350
Comfort+ membership, a water heater flush with a sewer camera inspection every year included
$199 a year
Both visits include a whole-home plumbing check: supply lines, shutoffs, a pressure reading, drains, toilets and traps.
One per household, owner-occupied homes, limited time. A leaking tank, or one that’s 15 years old, needs repair or replacement, not a flush.
More for the money: Comfort+ membership, $199 a year, includes the flush and its plumbing check every year, plus a sewer camera inspection, a dryer vent cleaning and heating and cooling maintenance visits.
What’s different in Marshall
Iron from Marshall’s wells, and FCWSA flushing the village mains in March and September.
Inside the Marshall service district the water belongs to the Fauquier County Water and Sanitation Authority, pumped from deep wells drilled into fractured bedrock. FCWSA’s report for 2025 lists six of them, 285 to 445 feet down, one offline. Some carry iron and manganese, two at very high levels, so the Authority filters the 17/66 wells through greensand and feeds a phosphate at two well sites to hold down color and sediment.
FCWSA flushes the Marshall mains on a schedule, and for 2026 that’s March 16 to 19 and September 21 to 24. During a flush you may get low pressure, air and brown water; the Authority recommends no laundry or bathing until it’s done, then a cold tap run for a few minutes to clear the line. Leave the hot taps alone that day. Anything pulled through a hot tap while the mains are stirred up settles in your tank, and a flush after the September round sends it out the drain valve.
FCWSA’s drought page adds that a well pumping long summer hours can send out harder or more discolored water than the same well does in winter. By fall a Marshall tank has had its hardest-working months of well water through it, so autumn is a good time to drain it.
Past the service district the water is your own well’s. More than half the Fauquier households that sent samples to Virginia Cooperative Extension’s clinics from 2012 to 2017 had treatment in place, a sediment filter most often, and a filter catches most grit, not all. About one owner home in five in 20115 heats with propane, and where the water heater burns it too, the burner fires right under that sediment; that’s the popping you hear. The well, its pump and the pressure tank belong to a well contractor; we start at the water heater.
By the numbers
Marshall houses, by the numbers
From the Census Bureau’s 2020 to 2024 survey. Median year built and heat count owner-occupied homes only.
Marshall
ZIP 20115 as a whole: every Marshall address, the village included. The Census place for the village alone has too few homes for steady figures.
- Median home built1986 Census
- Built before 1980about 4 in 10 Census
- Built since 2000about 2 in 10 Census
- Most homes aresingle-family houses, about 8 in 10 Census
- Heated withelectricity, about 6 in 10 Census
- Rentedabout 3 in 10 Census
- In Marshall, about 6 in 10 owner homes heat with electricity. On an electric water heater, sediment settles around the lower heating element, and clearing it is part of the flush.
When it’s due
Why people in Marshall book a flush.
It pops or rumbles
That’s water boiling under a layer of sediment on the bottom of the tank. A flush clears it out.
Nobody knows when it was last done
Which is most houses. The drain valve at the bottom of the tank has usually never been opened.
Choosing who does it
How to pick who flushes your water heater in Marshall.
Questions worth asking anybody you call, us included.
Do they ask what treatment sits ahead of the heater?
On a private well there may be a sediment filter, a softener or an acid neutralizer in the line, and each changes what reaches the tank. Anybody flushing heaters around Marshall should ask first, and tell you if the filter cartridge looks spent.
Do they check the anode rod and test the relief valve?
The anode is the part that corrodes so the tank doesn’t, and the relief valve is the tank’s safety valve. A flush that skips both is just draining water.
On a tankless, do they pump descaler through it?
A real descale isolates the heater at its service valves and pumps solution through the heat exchanger, then rinses it and cleans the inlet screen.
Two of our crew going over a work order before the day's calls.
From our Google reviews
What our customers say.
5.0 stars across 1,132 reviews. Read them on our reviews page.
I had a really pleasant personal experience with Swiftpro when my water heater went out. The pricing was very reasonable compared to the many other HVAC companies I sought quotes from. I highly recommend them
Where we work
Water heater flush in every Northern Virginia town we serve
Next door to Marshall: Rectortown, Delaplane, The Plains, Orlean and Broad Run.
Fairfax County
Arlington County
Loudoun County
Prince William County
Fauquier County
Stafford County
Questions
Water heater flush questions from Marshall.
Is Marshall’s water hard?
There’s no published figure. FCWSA’s 2025 report for the Marshall system names iron and manganese as its issue and leaves hardness out, and a tank collects that sediment either way, so drain it yearly. For a tankless, a test strip tells you the maker’s descale interval.
When is the best time to book a flush in Marshall?
On FCWSA water, after the fall main flushing, scheduled for September 21 to 24 in 2026, so whatever the mains shed goes out with the flush. On a well, any month works; tell us if there’s a filter or a softener in the line.
How much does a water heater flush cost in Marshall?
$99 right now for a tank, normally $199, with a whole-home plumbing check. A tankless descale is $300 right now, regularly $350. Comfort+ membership, $199 a year, includes the flush every year.
Ready when you are
Book the flush, tank or tankless.
Call, or send the form at the top. Tell us tank or tankless, and the tech brings the right gear.
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 Marshall and the rest of Northern Virginia. Virginia contractor license #2705192276. 5.0 stars across 1,132 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.