A tank flush is $99 right now, with a whole-home plumbing check, normally $199. A tankless descale is $300, regularly $350.
Tell us which one you have and that’s the price. Both visits come with the same whole-home plumbing check, and you pay after the visit.
Tank water heater
$99$199
The $149 plumbing check comes with it.
Tankless water heater
$300$350
Navien, Rinnai, Rheem, Noritz. The same plumbing check comes with it.
One per household. Owner-occupied homes in Northern Virginia. Not combinable with other offers. Limited time. Normal price is $199 for the flush, $149 for the safety check and $350 for the tankless descale. The same offer, with online booking, is on our $99 flush page.
Hardness decides it. Hard water leaves minerals behind as it heats: sediment in the bottom of a tank, scale inside a tankless. Navien’s manual draws the line at 4 grains per gallon. From there up, with no softener on the line, it calls for a flush every year. Here’s what each utility here published.
Most of Fairfax County, plus the City of Fairfax and Falls Church. Flush pages: Fairfax, Reston, Chantilly.
Ashburn, Sterling and South Riding. Prints no hardness figure. Its water comes from Fairfax Water’s Potomac plant, which ran 4.1 to 10.8 in 2025. Source. Flush pages: Ashburn.
Woodbridge, Gainesville and Bristow, and most of Manassas outside the City. Flush pages: Woodbridge.
Once a year, whichever water you’re on. If it already pops or rumbles when it heats, don’t wait for the date to come around.
Once a year above the line, which is nearly everywhere we work. The City of Manassas is the exception: at 2.7 grains, Navien’s table doesn’t call for it.
There’s no utility number to go by, and wells vary house to house. A water test gives you the hardness, and the hardness sets the interval.
Grains per gallon from each utility’s own report. Where a utility prints milligrams per liter, we divided by 17.1.
Water under the tank, or a tank that’s 15 years old? A flush won’t save it. Here’s what a repair or a new water heater costs.
4 grains and up: once a year
Navien’s manual calls for a flush once a year in a home wherever the water runs 4 to 12 grains per gallon and there is no softener or scale filter on the line.
The biggest single reason
“Scale build-up from hard water is the biggest single reason for unit failures.”
Not covered
Navien’s warranty is void for damage from “hard water deposits, lime or mineral build-up”, and for failure to perform regular maintenance.
Five questions worth asking anybody you call, us included.
It’s the part that corrodes so the tank doesn’t. A flush that skips it misses the one thing that decides how long the tank lasts.
The temperature and pressure relief valve is the tank’s safety valve. It should get opened at the flush, and if it won’t close clean again, you want to know while someone’s standing there.
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. Running vinegar through a faucet isn’t it.
Ask what it covers, and whether the trip or the inspection costs extra. Ours is the whole price of the visit, not a deposit on something bigger.
You shouldn’t have to track down whoever put it in. We work on Navien, Rinnai, Rheem, Noritz, A. O. Smith and Bradford White, whoever installed it.
SwiftPro HVAC came out to do a plumbing maintenance check. The check was included with my recent new HVAC installation. The technician (James Milligan) was very professional and quickly evaluated my faucets, toilets, water heater, washing machine lines, main water intake valve, all cut-off valves and visible pipes. Now I have an estimate for needed maintenance repairs.
Jim was very professional, knowledgeable and polite plumber. He installed a water heater for us. After the installation he educated us on the maintenance and the new set up. I strongly recommend Jim/SwiftPro. Plus SwiftPro price was very reasonable/20% below other estimates.
The plumber, Tyson, was exceptional. He was friendly, courteous, competent and very thorough. He and Robert resolved our plumbing issues while providing an outstanding customer oriented service experience. Tyson did an excellent job installing our new hot water heater, thermostatic mixing valve and OneFlow TAC filter. Tyson is a true asset to your company and represents the Swift Pro brand well.
$99 right now for a tank, and that includes a whole-home plumbing check. The flush on its own is normally $199. A tankless descale is $300 right now, regularly $350. You pay after the visit.
Once a year for a tank. Most of the water around here runs moderately hard to hard, and sediment piles up faster in hard water. If yours already pops or rumbles, don’t wait for the year to come around.
Once a year in most of Northern Virginia. Navien’s manual calls for a yearly flush wherever the water runs 4 grains per gallon or harder with no softener, and nearly every utility here runs harder than that. The City of Manassas, at 2.7, is the exception.
You can. Turn the gas to pilot or switch off the breaker, close the cold supply, run a hose from the drain valve to somewhere that can take hot water, and open a hot tap upstairs so it drains. The catch is the drain valve: on a lot of tanks it’s plastic, and grit can stop it closing again. If that’s the part making you nervous, that’s the $99 visit.
Maybe not. After ten years the sediment can be packed hard, and opening the drain on a tank that age can start a drip that wasn’t there. We’d look first and tell you straight whether a flush is worth it or whether that money is better put toward the next heater.
On a tankless, yes. With a softener or a scale filter on the line, Navien’s table stops calling for the yearly flush. A tank still collects some sediment either way, so it still gets flushed.
There’s no utility report to go by, so the water test is the number that counts. Well water can run harder than the public water, or carry grit. We don’t do well work, but we’ll flush the heater and tell you what came out of it.
Yes. Navien, Rinnai, Rheem, Noritz, A. O. Smith, Bradford White, whoever put it in.
You get photos and a price, and time to think about it. Nothing gets fixed unless you say yes, and nothing on this visit is a deposit on anything else.
Call, or book online and pick a window. Tell us tank or tankless, and the tech shows up with the right gear.
SwiftPro Heating, Cooling & Plumbing, 4230 Lafayette Center Dr N, Chantilly, VA 20151, (703) 997-9757. Virginia contractor license 2705192276. Independently owned, with a dedicated HVAC team and a dedicated plumbing team.
Water heater flushing and tankless descaling across Fairfax, Loudoun, Arlington and Prince William counties, along with water heater repair and replacement, plumbing, heating and cooling.
More reading: water heater maintenance, tankless maintenance, hard water where you live, and the town by town guide.
