Bristow, VA Water Hardness (2.6 to 10.5 grains per gallon) and Your Water Heater

The water in Bristow, by the numbers

Water utilityPrince William Water

Hardness2.6 to 10.5 grains per gallon2025

What that isSoft to hardU.S. Geological Survey classes

ZIP codes20136

How oftenFlush a tank once a yearDescale a tankless yearly too

Owner-occupied homes11,087half built before 2004

Source: Prince William Water water quality report; U.S. Census Bureau, American Community Survey 2020 to 2024, median year built; U.S. Geological Survey, Hardness of Water.

What it means for your water heater

Hard water carries calcium and magnesium. Heat a tank of it and some drops out as sediment on the bottom, under the burner or the lower element. That's what makes a water heater rumble and pop, take longer to recover and wear out early. Flushing it once a year clears it out.

Popping or rumbling while it heats. That is water boiling under a layer of sediment.
Grit in the faucet screens on the hot side.
A drain valve nobody has opened since the house was sold.

A tankless gets descaled instead. Navien's manual calls for it once a year wherever the water runs 4 grains per gallon or harder with no softener, and the water in Bristow does. Descaling is $300, regularly $350.

Half the owner-occupied homes in Bristow were built before 2004. A house that age can still have its original shutoff valves and supply lines, which is why every flush comes with the plumbing safety check: supply hoses, shutoff valves, water pressure and drains, with photos of anything worth knowing about.

More on the flush in Bristow on SwiftPro's Bristow water heater flush page.

The rest of the water in Bristow

Hardness is one line of Prince William Water's testing. The full Prince William Water water report shows every contaminant it found, next to the legal limit and the health guideline. On a private well, a test at your own tap is the number that counts.

Nearby towns

Questions people ask

Is Bristow water hard?

Yes, soft to hard. Prince William Water reported 2.6 to 10.5 grains per gallon in 2025. The U.S. Geological Survey calls anything over 7 grains per gallon hard.

How often should I flush my water heater in Bristow?

Once a year for a tank. A tankless gets descaled once a year too, because the water in Bristow is over Navien's 4 grains per gallon line.

How much is a water heater flush in Bristow?

$99 at SwiftPro, normally $199, with the plumbing safety check included. Tankless descaling is $300, regularly $350. You pay after the visit.

Get it flushed for $99.

Normally $199, with the plumbing safety check included. Tankless descaling is $300, regularly $350. Pick a time online, and you pay after the visit.

Pick a time Call (571) 396-0299