Water heater repair and replacement in Herndon.
Water heater repair and replacement in Herndon, Town or county side, priced from our book with the permit and the expansion tank already in it.
A new water heater installed with the permit runs $2,757 to $5,493 for an electric tank, $3,379 to $5,485 for gas or propane and $8,886 to $10,486 for tankless. The water heater estimator gives your exact number.
- Permit and expansion tank included
- Tank or tankless
- Dedicated plumbing team
Get your water heater priced
In the Town of Herndon, the water heater is usually electric.
About six in ten owners inside the Town of Herndon heat with electricity, and a house without gas heat usually has an electric water heater too. That’s the simpler swap: no flue to check and no gas line to size, just the right tank, a drain pan and an expansion tank.
Gas is more common out on the county side. About six in ten owners in Floris and seven in ten in McNair heat with gas, and there a gas tank swap takes a Fairfax County permit and a chimney vent certification even like for like. Inside the town the permit comes from the Town of Herndon instead.
Most homes in the town went up in the 1970s and 80s, so the heater in them now is a second or third, and plenty sit in townhouse closets and condo utility rooms rather than an open basement. Up there, the drain pan and the line out of it are what keep a failing tank off the ceiling below.
If a tank does let go inside the town, hang on to our invoice. Owners can ask the Town for a courtesy leak adjustment once every five years, and for a leak inside the house it credits 66 percent of the excess water, as long as the repair happened within 10 days and the contractor’s invoice spells it out.
What’s heating the water across Herndon.
Census figures for each place, and the water heater that usually goes with its houses. Median year built and heat count owner-occupied homes only.
| Place | Median home built | Most homes are | Heated with | The water heater you usually find |
|---|---|---|---|---|
| Franklin Farm | 1985 | single-family houses, about 9 in 10 | electricity, about 5 in 10 | Mostly electric tanks, no flue. |
| Herndon | 1981 | single-family houses, about 4 in 10 | electricity, about 6 in 10 | Mostly electric tanks, no flue. |
| Dranesville | 1984 | single-family houses, nearly all | electricity, about 6 in 10 | Mostly electric tanks, no flue. |
| McNair | 2003 | condo and apartment buildings, about 6 in 10 | gas, about 7 in 10 | Condo closets: gas or electric tanks, over a pan. |
| Floris | 1990 | single-family houses, about 8 in 10 | gas, about 6 in 10 | Gas tanks on their second or third replacement. |
| Hutchison | 1979 | townhouses, about 5 in 10 | electricity, about 7 in 10 | Mostly electric tanks, no flue. |
| Sully Square | 2015 | condo and apartment buildings, about 6 in 10 | gas, about 6 in 10 | Condo closets: gas or electric tanks, over a pan. |
Herndon houses, by the numbers
From the Census Bureau’s 2020 to 2024 survey. Median year built and heat count owner-occupied homes only.
The Town of Herndon
Inside the town limits. Floris, Franklin Farm, McNair and Dranesville, on the Fairfax County side, are counted by the Census as places of their own.
- Median home built1981 Census
- Built before 1980about 4 in 10 Census
- Built since 2000about 2 in 10 Census
- Most homes aresingle-family houses, about 4 in 10 Census
- Heated withelectricity, about 6 in 10 Census
- Rentedabout 4 in 10 Census
- Where the heat is electric the water heater usually is too, and that’s the simpler swap: no flue and no gas line to deal with.
What a new water heater costs in Herndon.
Installed, from our water heater estimator, which is the price book. Everything is in the number: the permit and the inspection, the expansion tank, the drain pan, hauling the old one away, and the labor.
- Electric tank, installed$2,757 to $5,493
- Gas or propane tank, installed$3,379 to $5,485
- Power vent tank, installed$5,957 to $7,494
- Tankless, installed$8,886 to $10,486
How the house vents picks the row; where you land inside it is the tank size and the warranty. A hybrid heat pump water heater is quoted at the visit, never from a page.
Keeping the one you have? A yearly water heater flush slows the sediment down: $99 right now, normally $199. A tankless descale is $300, regularly $350. Or get the flush every year with Comfort+ membership, $199 a year, along with a dryer vent cleaning, a sewer camera inspection and heating and cooling maintenance visits.
What a failing water heater in Herndon usually does.
A damp drain pan in an upstairs closet
About half the homes in the town are townhouses or condos, so plenty of tanks sit upstairs or over a neighbor. A pan with water in it, or a drip from the line it drains to, is the early warning; call then, before the tank decides the day.
Warm, never hot, on an electric tank
An electric tank has two elements. When one fails the water still warms, just never all the way; it’s a common, fixable part.
Water on the floor around it
A drip from a valve can be fixed. Water from the tank itself can’t; once the lining goes, the only fix is a new heater, and sooner beats later.
After a storm in Herndon, check the water heater.
A water heater usually sits on the lowest floor of the house, so it’s one of the first things standing water reaches. Three checks, then call us.
Water reached the burner or the gas controls
Leave it off and don’t relight it. The warning label on a gas water heater says not to use it if any part has been under water, and to have a service technician replace the gas control.
An electric tank sat in water
Shut its breaker off at the panel, but only from somewhere dry. The elements and the thermostats get checked before it heats again.
Water around it after the rain stopped
Mop it up and look again in an hour. Water that comes back with no rain is the tank or a valve, not the storm.
Call us after a storm and we’ll check it: the gas control or the elements, the burner, the venting and the drain pan. If it has to be replaced, you get the price in writing before anything comes out.
Who signs off on a new water heater in Herndon.
Town of Herndon
Inside the town, the permit for a water heater swap comes from the Town of Herndon, not Fairfax County. Under the statewide code it enforces, a gas tank needs one even like for like. Source.
The Town takes an emergency permit application for water service, heat or electrical service before its usual tax and business license checks are cleared. Source.
Town Code keeps the Town’s side of the water line on the street side of the meter, never past its outlet. From the meter in, the service line and everything on it, a pressure reducing valve included, is the owner’s to keep up. Source.
Fairfax County
Fairfax County requires a permit to replace any gas appliance, even like for like: a gas water heater, furnace or boiler. Replacing a fuel-burning appliance also needs a chimney vent certification. Source.
Virginia lets emergency replacement work start first, with the permit application in by the end of the next working day. Source.
Fairfax Water promises 20 psi at the main and no uniform pressure, and the pressure reducing valve on your side of the meter is yours to buy and keep up. Over 80 psi, the Virginia Residential Code calls for one, and an expansion tank with it. Source.
How to pick the best water heater installer in Herndon.
Questions worth asking anybody who quotes you, us included.
Do they know which office signs off on your street?
A Herndon address can be inside the town, where the Town inspects the work, or out in Fairfax County. A plumber who works here asks which before quoting.
Is the permit in the price?
A gas water heater always needs a permit, an electric one often does, and skipping it tends to surface when the house sells. Ask whether the quote includes it and the inspection.
Is there an expansion tank in the quote?
Most houses here have a check valve or a pressure reducer on the incoming line, so the heated water has nowhere to go. An expansion tank gives it somewhere, and leaving it out is how quotes come in low.
Will they tell you when a repair will do?
A thermocouple, an element or a valve is a repair, not a new heater. A good plumber says so, and saves the replacement talk for a leaking tank.
What our customers say.
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!!
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Water heater questions from Herndon.
Do I need a permit to replace a water heater in Herndon?
For a gas one, yes, on both sides of the town line: from the Town of Herndon inside it, and from Fairfax County outside it, with a chimney vent certification. An electric swap can need one too, so our prices carry the permit wherever it’s needed: $2,757 to $5,493 for an electric tank, $3,379 to $5,485 for gas on the flue you have.
Is Herndon’s water hard on a water heater?
Moderately hard to hard. The Town buys from Fairfax Water and gets mostly Potomac water from its Corbalis plant, which ran 4.1 to 10.8 grains per gallon in 2025, hardest in the fall. That leaves sediment in a tank every year, which is what the yearly flush is for.
Can a Herndon townhouse go tankless?
Often, if there’s gas. A tankless unit needs a bigger gas line than a tank and a way to vent outside, and inside the town new gas line work goes on the Town’s plumbing and gas permit with a riser diagram. With electric heat and no gas, an electric tank is usually the right call. A tank runs $2,757 to $7,494 installed and tankless $8,886 to $10,486.
How much is a new water heater in Herndon?
Installed, with the permit, the expansion tank, the pan and the haul-away: an electric tank $2,757 to $5,493, a gas or propane tank on the flue you have $3,379 to $5,485, a power vent tank $5,957 to $7,494, and a tankless unit $8,886 to $10,486. The estimator gives your exact number in about a minute.
Water heaters in the towns next door.
- Water heaters in Reston
- Water heaters in Sterling
- Water heaters in Great Falls
- Water heaters in Oakton
- Water heaters in Chantilly
More from SwiftPro in Herndon
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SwiftPro Heating, Cooling & Plumbing is a licensed, BBB Accredited (A rating), independently owned heating, cooling and plumbing company in Chantilly, serving Herndon and the rest of Northern Virginia. Virginia contractor license #2705192276. 5.0 stars across 884 Google reviews. SwiftPro maintains a dedicated HVAC team and a dedicated plumbing team.
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