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In Great Falls, 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.
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 Great Falls under Virginia Class A contractor license 2705192276, and SwiftPro is rated 5.0 stars across 1,130 reviews. Tankless water heaters in Great Falls: what a house on gas, propane or all electric can take, and how a big house with a basement suite gets sized. 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.
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.
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Licensed and insuredVirginia Class A contractor #2705192276
24/7 emergency serviceWe answer day or night, 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
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 Great Falls
Less than half of Great Falls owner homes burn utility gas. About four in ten are all electric and roughly one in twelve runs on propane. So before we talk units, we ask what feeds the furnace. A house on natural gas or propane can take a condensing tankless. A house with neither is usually better off with another tank, and we’ll say so before we sell you a whole-house electric unit your panel can’t carry.
Propane works for tankless; it’s the same unit set up for the other fuel. What gets checked is the tank in the yard and the regulator and pipe between it and the house, because a tankless burner pulls hard when it fires.
These are big houses. The county’s records put the middle one at four full bathrooms, and plenty have a soaking tub upstairs and a bathroom in the basement. One tankless unit can only heat so much water per minute, so in a five bath house the real question is how many taps open at once. Sometimes one large unit does it. Sometimes the basement suite gets its own small unit. We size from your fixtures and tell you which before the quote.
About two in three houses have a daylight basement, where the ground falls away and one wall opens to the yard. That helps: the PVC vent and intake can go straight out that wall in a short run, and the condensate has somewhere to drain. Half the houses date from the 1970s and 80s, so the gas line was likely sized for a furnace and a tank, and we trace it before we promise a price. New gas piping takes its own Fairfax County permit, which we pull.
By the numbers
From the Census Bureau’s 2020 to 2024 survey. Median year built and heat count owner-occupied homes only.
Is it worth it
When the heater sits at one end of the basement and the guest bath is at the other, you wait while the cold runs down the drain. A small tankless unit near the new bathroom can fix that and leave the old tank alone.
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.
A tankless unit hangs on a wall about the size of a carry-on bag. Where a 50 or 75 gallon tank took a corner of the utility room, the floor under it is yours again.
Need tankless water heaters in Great Falls?
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Choosing who installs it
Questions to ask anybody who quotes you a tankless, us included.
In Great Falls it could be gas, propane or electric. An installer who pitches the same unit to every house hasn’t looked at yours.
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.
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
5.0 stars across 1,130 reviews. Read them on our reviews page.
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!!
Questions
Yes. The unit is set up for propane at the factory or with a conversion kit, and the vent is the same. The line from your yard tank gets sized for it first, and your propane company stays your fuel supplier.
Usually a new electric tank, because a whole-house electric tankless needs far more amperage than most panels have spare. Our water heater estimator shows the tank options, and if propane is on your mind we can talk through what adding it takes.
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.
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
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 Great Falls 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.