Water heater repair and replacement in Fairfax.
Water heaters in the City of Fairfax and the county side, repaired or replaced with the permit and the expansion tank in the price.
- Permit and expansion tank included
- Tank or tankless
- Dedicated plumbing team
Get your water heater priced
In Fairfax, most water heaters burn gas, and pressure wears them out.
In the City of Fairfax and Mantua about seven in ten homeowners heat with gas, and the water heater usually burns gas as well, venting up the chimney it has used since the house went up in the 1960s. Fairfax Water’s 2025 hardness ran 3 to 10.8 grains per gallon depending on the plant and the month, enough to build sediment in a tank a little every year.
Pressure is the other thing that ages them. Fairfax Water doesn’t promise an even pressure, and over 80 psi a water heater’s relief valve and fittings take a beating. That’s why the code wants a pressure reducing valve above 80 psi, and why every replacement we price comes with an expansion tank.
Where the tank sits depends on the neighborhood. In the City and Mantua it’s usually in the basement or a utility room beside the furnace, close to a floor drain. Kings Park West, mostly 1970s, has the most electric heat of any place with a Fairfax address, close to half its homeowners, so an electric tank with no flue is common there. In Fair Oaks and Merrifield half or more of the homes are in condo and apartment buildings, where the heater lives in a closet over a pan and a leak shows up downstairs first.
Inside the city line the permit comes from the City of Fairfax’s own office. Outside it, Fairfax County’s household appliance permit has no plan review: it’s issued once it’s applied for and paid, and one inspection follows. Going tankless changes the paperwork. A tankless unit usually needs a bigger gas line than the old tank, and in Fairfax County new gas piping turns the job into a plumbing permit.
What’s heating the water across Fairfax.
Census figures for the owner-occupied homes in each place, and the water heater that usually goes with them.
| Place | Median home built | Most homes are | Heated with | The water heater you usually find |
|---|---|---|---|---|
| Fair Oaks | 1995 | condo and apartment buildings, about 5 in 10 | gas, about 6 in 10 | Condo closets: mostly electric tanks. |
| City of Fairfax | 1966 | single-family houses, about 5 in 10 | gas, about 7 in 10 | Gas tanks, often sharing a chimney with the furnace. |
| Kings Park West | 1976 | single-family houses, about 7 in 10 | gas, about 5 in 10 | Gas tanks, often sharing a chimney with the furnace. |
| Merrifield | 1990 | condo and apartment buildings, about 6 in 10 | gas, about 6 in 10 | Condo closets: mostly electric tanks. |
| Fair Lakes | 1998 | townhouses, about 3 in 10 | gas, about 7 in 10 | Gas tanks on their second or third replacement. |
| Mantua | 1968 | single-family houses, about 7 in 10 | gas, about 7 in 10 | Gas tanks, often sharing a chimney with the furnace. |
Fairfax houses, by the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
The City of Fairfax
- Median home built1966 Census
- Built before 1980about 7 in 10 Census
- Built since 2000about 2 in 10 Census
- Most homes aresingle-family houses, about 5 in 10 Census
- Heated withgas, about 7 in 10 Census
- Rentedabout 3 in 10 Census
- Most houses here heat with gas, so most water heaters are gas tanks, and replacing one takes a permit even like for like.
- In older houses the gas water heater often shares a chimney with the furnace, and a new high-efficiency furnace can leave it alone on a flue that’s too big.
The Fairfax County side
- Built before 1980about 3 in 10 Census
- Built since 2000about 4 in 10 Census
- Most homes arecondo and apartment buildings, about 4 in 10 Census
- Heated withgas, about 6 in 10 Census
- Rentedabout 5 in 10 Census
- Condo water heaters are usually electric and in a closet, and some buildings have their own rules on who replaces them and when.
What a new water heater costs in Fairfax.
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 flush slows the sediment down; our water heater flush page has the details for your water.
What a failing water heater in Fairfax usually does.
Soot at the top of a gas tank
That means exhaust is spilling out of the draft hood instead of going up the chimney. In a 1960s Fairfax house it often starts after the furnace was swapped for one that vents out the wall, leaving the water heater alone on a flue sized for two. Turn the heater off and call.
The pilot won’t stay lit
On a gas tank that’s usually the thermocouple or the gas valve, both repairs. A burner that lights but smells of exhaust is different: shut it off and call.
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.
Who signs off on a new water heater in Fairfax.
Fairfax County
Virginia lets emergency replacement work start first, with the permit application in by the end of the next working day. Source.
How to pick the best water heater installer in Fairfax.
Questions worth asking anybody who quotes you, us included.
Do they know whether you’re in the City or the County?
A Fairfax mailing address can sit inside the city line or out in the county, and each one runs its own permit office. The installer should know which yours answers to before writing the quote, because that’s who inspects the new heater, and on the county side the chimney gets a vent certification too.
Is the permit in the price?
Replacing a water heater is permitted work here, and skipping the permit tends to surface when the house is sold. 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.
I would gladly recommend them to anyone in the greater Fairfax/Alexandria area without reservation.
Swiftpro came out the same day I called when my AC was out and had it fixed in less than an hour after arriving.
Had the water heater replaced and a quote for my HVAC. Both technicians were friendly and helpful. Prices were decent. Would use again.
5.0 stars across 884 Google reviews. Read them on our reviews page.
Water heater questions from Fairfax.
My water heater’s relief valve keeps dripping. What does that mean?
Usually pressure: either the water coming in is too high or there’s no working expansion tank to take up the heated water. It’s a cheap fix compared with ignoring it, and it’s worth a gauge on the outside spigot to find out which.
How long do water heaters last in Fairfax?
Most tanks here quit somewhere past ten years, and sooner in a house that runs over 80 psi or hasn’t seen a flush. The build date is printed on the label. If yours is past ten and rumbling, price the replacement now, while you still have hot water to decide with.
Can a 1960s Fairfax house take a tankless water heater?
Usually, with some work. The old gas line was sized for a tank, while a tankless unit burns far more gas when it fires and usually vents out a wall rather than up the chimney. We look at both before we quote it. Installed, tankless runs $8,886 to $10,486; a gas tank on the flue you already have is $3,379 to $5,485.
How much is a new water heater in Fairfax?
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 Oakton
- Water heaters in Burke
- Water heaters in Vienna
- Water heaters in Annandale
- Water heaters in Springfield
More from SwiftPro in Fairfax
Tell us how old yours is.
Call, or book online and pick a window. The age on the label and what it’s doing tell us most of what we need, and you get the price before anything comes out.
SwiftPro Heating, Cooling & Plumbing is a licensed, BBB Accredited (A rating), independently owned heating, cooling and plumbing company in Chantilly, serving Fairfax 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.
SwiftPro Heating, Cooling & Plumbing, 4230 Lafayette Center Dr, Suite N, Chantilly, VA 20151, (703) 997-9757. Book online, read our reviews, or see every town we serve.