A house that has grown past its tank
In a South Riding house with a soaking tub and two kids in the shower, a single tank runs out by the second turn. A tankless sized for the number of taps open at once fixes that, within its flow limit.
Chantilly, Virginia
Tankless water heaters in Chantilly.
In Chantilly, a tankless water heater installed is $8,886 to $10,486. That’s after $500 off any size, the best water heater deal we have. Call SwiftPro, rated 5.0 stars across 1,130 reviews, at (703) 997-9757, 24 hours a day, 7 days a week.
$148/mo60mo @ 0% APR
Price range
$8,886-$10,486
8yrs @ 7.99%
$126/mo
15yrs @ 9.99%
$95/mo
Monthly figures on the starting price, the whole price financed, on approved credit. The lender sets the final terms. How financing works
We install in Chantilly under Virginia Class A contractor license 2705192276, and SwiftPro is rated 5.0 stars across 1,130 reviews. We cover tankless water heaters in Chantilly and South Riding: the gas split between the two, and how the 1980s houses and the 2000s townhouses differ. Staying with a gas tank on the flue you have is $3,238 to $5,485. Once a year a tankless wants a descale, $300 right now, regularly $350.
- Gas line sized before the quote
- Our own licensed plumbers
- Descaled on a schedule
5.0 stars across 1,130 reviews
One of our plumbers at a wall-hung tankless unit, the condensate line and the PVC vent in view.
Get your price in writing
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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
What a tankless water heater costs in Chantilly.
Installed, from the same price book as our water heater estimator: the unit, the gas line work it needs, the new venting, the condensate drain, the permit and hauling the old tank away.
Tankless water heater, installed
$8,886 to $10,486
or $148/mo at 0% APR for 60 months
Gas or propane tank on the flue you have, installed
$3,238 to $5,485
or $54/mo at 0% APR for 60 months
Tankless descale, with the plumbing check
$300, regularly $350
Monthly figures: 60mo @ 0% APR on each starting price, the whole price financed, on approved credit. Longer plans lower the payment and cost more in total. The lender sets the final terms. How financing works
Prices checked .
Where you land in the range is mostly the gas line. A tankless burner fires far harder than a tank’s, so an older line sized for a tank often has to be upsized from the meter. We look before we quote, so that’s in the number, not a surprise.
A tankless unit’s heat exchanger scales up in hard water, so it wants a descale every year: $300 right now, regularly $350. We’ll show you the inlet screen and what came off it.
What’s different in Chantilly
Chantilly and South Riding are two different tankless jobs.
Chantilly itself splits almost down the middle on heat: 53 percent gas, 44 percent electric. South Riding is nearly all gas, at 84 percent. So the page you are reading is really two. In South Riding, almost every house has the gas already. In Chantilly, ask first whether yours does, because a house on electric usually stays with a tank.
Six in ten Chantilly homes went up between 1980 and 1999, and the median is 1987. Those were built with a utility room or basement along an outside wall, so the PVC vent has a short trip. The gas pipe is generally better sized than in a 60s house, but it was still planned around a tank, so we measure the run from the meter and the other appliances on it.
South Riding is the opposite end of the clock. Over three quarters of the homes went up since 2000, with a median of 2006, and they split between single-family houses and townhouses almost evenly. The builders ran gas to the kitchen, the fireplace and often a second floor, so a larger line is frequently already in the wall. The question there is the wall for the vent.
That wall is where townhouses sort themselves out. An end unit has a side wall; a middle unit does not, and the vent has to come out the back, clear of the deck and the windows. Detached South Riding houses with three and four bathrooms are the ones where a tankless pays off most, since the original tank was never meant for that many showers.
Neighborhood by neighborhood
What a tankless install looks like across Chantilly.
Census figures for the owner-occupied homes in each place, and what usually decides a tankless job in houses like them.
| Place | Median home built | Most homes are | Heated with | What usually decides the job |
|---|---|---|---|---|
| South Riding | 2006 | single-family houses, about 5 in 10 | gas, about 8 in 10 | Replacing the builder tank, and where the vent goes. |
| Chantilly | 1987 | single-family houses, about 6 in 10 | gas, about 5 in 10 | A short PVC vent out the basement wall. |
By the numbers
Chantilly houses, by the numbers
From the Census Bureau’s 2020 to 2024 survey. Median year built and heat count owner-occupied homes only.
20151, the Fairfax County side
- Median home built1987 Census
- Built before 1980about 2 in 10 Census
- Built since 2000about 2 in 10 Census
- Most homes aresingle-family houses, about 6 in 10 Census
- Heated withgas, about 5 in 10 Census
- Rentedabout 2 in 10 Census
- Not every house here has gas, and a whole-house electric tankless needs more amperage than most panels have to spare. Where there’s no gas line, we price a tank instead and say why.
- In houses from the 80s and 90s the water heater usually sits in the basement near an outside wall, which keeps the PVC vent run short.
20152, the South Riding side
- Median home built2006 Census
- Built before 1980hardly any Census
- Built since 2000about 8 in 10 Census
- Most homes aresingle-family houses, about 5 in 10 Census
- Heated withgas, about 8 in 10 Census
- Rentedabout 2 in 10 Census
- Most homes here heat with gas, so the meter and the main line are already there. The question is whether the branch to the water heater is big enough.
- In houses built since 2000 the original tank is reaching its years, and the utility room was laid out around it, so we check where the vent and the condensate line can go.
Is it worth it
When going tankless makes sense in Chantilly.
The builder tank is near the end
If the original tank is past ten years, the choice is coming either way. Pricing tankless now, while you still have hot water, beats deciding the morning it leaks.
The hot water runs out every morning
When two showers and the dishwasher empty the tank before everyone’s done, a tankless heats as you use it. It won’t run dry, but it has a flow limit, so it’s sized to how many taps run at once.
Need tankless water heaters in Chantilly?
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Choosing who installs it
How to pick the best tankless installer in Chantilly.
Questions to ask anybody who quotes you a tankless, us included.
Do they ask which side of the county line you are on?
Chantilly is in Fairfax County and South Riding is in Loudoun, and the permit can come from different offices. The installer should know which one yours answers to before you sign.
Did they look at the gas line before the price?
A tankless burner can draw several times what a tank does. A quote written without checking the line from the meter is a quote that grows on install day.
Do they size it to your flow, not the house’s square feet?
What matters is how many showers and faucets run at the same time, and how cold the water comes in during winter. Ask what flow rate they sized it for and why.
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 1,130 reviews. Read them on our reviews page.
Arrived within an hour on a Sunday morning and provided great service.
Called SwiftPro around 5 am and their electronic system scheduled an appointment for us same day.
This Company installed a tankless water system!!! They were great!!! Very Professional & Efficient & they Cleaned up & took out the old water tank! I would highly recommend them!!
- 5.0stars across 1,130 reviewsHow we count them
- ABBB Accredited, A ratingCheck it on bbb.org
- 2026Voted a Nextdoor Neighborhood Faves winner two years running: 2026 in 30 Northern Virginia neighborhoods, 2025 in Emerald Chase (Herndon) and Hunters Run (Chantilly)See it on Nextdoor
- #1BusinessRate Best of 2026: the top-ranked heating contractor in Fairfax, VirginiaSee our BusinessRate score
- Class AVirginia contractor, license #2705192276Look it up with DPOR
Where we work
Tankless water heaters in every Northern Virginia town we serve
Next door to Chantilly: Centreville, Aldie, Oakton, Fairfax and Haymarket.
Fairfax County
Arlington County
Loudoun County
Prince William County
Fauquier County
Stafford County
Every town on one page
Questions
Tankless questions from Chantilly.
Is my Chantilly house on gas?
Look for a gas meter outside and a flue pipe on top of the tank. About half of Chantilly homeowners use gas and nearly as many use electricity, so it is worth checking. No gas line usually means you stay with a tank.
Can a South Riding townhouse get a tankless?
Most can, if there is a wall to vent through. Gas is nearly everywhere there, so the wall is the deciding factor. End units are easier than middle units, and we look at the exact spot before pricing it.
How much is a tankless water heater in Chantilly?
Installed, $8,886 to $10,486, with the gas line work, the venting, the condensate drain and the permit in that number. A gas tank on the flue you have is $3,238 to $5,485, so the gap is what you pay for the floor space and the hot water that keeps up.
Will a tankless keep up with my whole house?
It never empties, because there’s no tank to empty. It does have a limit on how much hot water it makes per minute, and in January, when the water comes in cold, that limit drops. Sized to the number of showers you run at once, a family doesn’t notice.
Ready when you are
Find out if your house is a fit.
Call, or send the form at the top. We look at the gas line, the wall it would vent through and how much hot water you run at once, and you get the price in writing before anything comes out.
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 Chantilly 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.