Heating, cooling and plumbing in Great Falls, well and septic included.
Big houses on wells and septic, heated by gas, heat pumps, propane or oil. What we find in Great Falls homes, what the work costs, and who signs off.
- Prices in writing, first
- Dedicated HVAC and plumbing teams
- Virginia license #2705192276
Get your price in writing
Big houses on big lots, with the utilities in the yard.
Nearly every home in Great Falls is a single-family house on its own lot, and two things decide most of what we find: how big the house is, and what’s buried out back.
The houses are big. Fairfax County’s tax records put the middle Great Falls house at about 3,700 square feet above ground, before the basement, with four full bathrooms. Nine in ten have a full basement, and most of those are finished. The Census gives the median home nine rooms or more, the top of its scale. A house that size usually runs two or three heating and cooling systems and, often, more than one water heater.
The lot carries its own water and drains. About two in three home addresses in 22066 sit outside the county’s sewer service area, where the house drains to a septic tank. And close to a quarter of all the private wells the Health Department has mapped in Fairfax County are inside the Great Falls Census area. The village along Georgetown Pike and Walker Road is outside the sewer area; Holly Knoll and Great Falls West are inside it.
The heat comes four ways. A little under half the owner homes burn natural gas and about four in ten heat with electricity, mostly heat pumps. About one in seven burn propane or heating oil, nearly five times the county’s share. Half the houses went up in the 1970s and 80s, so we expect copper supply, some grey polybutylene in the later ones, and a furnace on its second or third replacement.
Heating, cooling and plumbing for the whole house.
A dedicated HVAC team and a dedicated plumbing team, from our shop in Chantilly, across all of 22066.
Heating
Gas, electric, propane or oil, and often two furnaces or heat pumps under one roof. We work on all of them except the oil burners. The common no-heat repairs, flame sensors, igniters and control boards, are priced from the book before anyone opens a panel.
Cooling
Most Great Falls houses run more than one system, and a condenser under big trees packs its coil with leaves and seed. AC repair, duct cleaning and dryer vent cleaning each have their own page.
Plumbing
Drains that end at a septic tank, water that starts at a well, and four or five bathrooms in between. We handle the plumbing in the house and the line out of it, and tell you plainly when it’s the septic or well contractor’s turn.
One price book for a big house or a small one.
A bigger house doesn’t get a bigger price for the same repair. You get the number in writing before anybody starts.
- AC run capacitor replaced$240 to $370
- Refrigerant topped up$190 to $740
- Condensate drain cleared$175 to $420
- Repair diagnostic visitabout $99
- Drain cleaning, one fixture$200 to $800
- Main sewer line cleaning$850 to $1,650
- Leak detection$200 to $500
- Pressure reducing valve replacement$500 to $1,000
- Water heater, tank, installed$2,757 to $7,494
These rows come from the book behind our plumbing page and our AC repair page. A new water heater is priced on the water heater estimator, with the Fairfax County permit in the number.
Replacing a furnace, heat pump or air conditioner? The HVAC estimator gives an installed range by house size. In a house with two or three systems, price each one on its own.
Fairfax County signs off, and the lot supplies the rest.
Your water
There are two answers here. A house on Fairfax Water gets Potomac water from its Corbalis plant, which ran 4.1 to 10.8 grains per gallon in 2025, softest in May and hardest in November. A house on a private well gets whatever the ground gives it, and the county Health Department says to have well water tested every year.
Reports: Fairfax Water, 3 to 10.8 gpg.
Your permit office
Great Falls has no town government, so Fairfax County issues every permit. Replacing a furnace or water heater that burns natural gas, propane or oil takes one even like for like, along with a chimney vent certification.
Permit pages: Fairfax County.
Your sewer, or your septic
Most Great Falls houses are on septic. County code wants the tank pumped at least once every five years, and an alternative system, one with its own treatment unit, inspected by an operator every year. On public sewer you own the whole lateral, out to the county main.
Sources: the county’s sewer service area map and the county plan for Upper Potomac and the Health Department’s septic and well page.
What our customers say.
They sent a technician to my home in the same evening and continued to following up.
I placed an emergency call for pipes that had frozen and burst in my bathroom in the very early morning.
They were able to come early the next morning after I called.
5.0 stars across 884 Google reviews. Read them on our reviews page.
Voted a Nextdoor Neighborhood Faves winner two years running: 2026 in 30 Northern Virginia neighborhoods, 2025 in Emerald Chase (Herndon) and Hunters Run (Chantilly).
Listed in both the HVAC and Plumbing categories of Northern Virginia Magazine’s Best Home Experts directory, which is exactly how we’re built: a dedicated HVAC team and a dedicated plumbing team.
All of 22066, from Leesburg Pike up to the river.
Inside the sewer service area: neighborhoods like Holly Knoll, Locust Hill and Great Falls West, and the edge along Leesburg Pike. Outside it, on septic: the village at Georgetown Pike and Walker Road, and neighborhoods like Lexington Estates, Hickory Creek and Lockmeade, out along River Bend Road and Beach Mill Road. Next door:
Great Falls questions.
Is all of Great Falls on septic?
No, but about two in three home addresses are outside Fairfax County’s sewer service area. The county’s plan keeps public sewer out of most of the Great Falls planning areas to hold them to large lots, and when it let a line reach Forestville Elementary and Great Falls Nike Park, it wrote that the sewer was for those two properties only. Neighborhoods like Holly Knoll and Great Falls West are inside the sewer area.
Who do I call when the well acts up?
A licensed well contractor, for the well, the pump and the line up to the house; that’s how the county Health Department divides it. From the pressure tank into the house it’s plumbing, and that part is ours: pipes, fixtures, water heaters and drains.
How hard is the water in Great Falls?
It depends where yours comes from. On Fairfax Water, its Potomac plant ran 4.1 to 10.8 grains per gallon in 2025. On a well, your own test is the number. Either way it’s hard enough to leave sediment in a tank water heater, which is why SwiftPro suggests a yearly flush.
Who issues permits for heating and plumbing work in Great Falls?
Fairfax County. Great Falls is unincorporated, so there’s no town office in the middle. A furnace or water heater that burns natural gas, propane or oil needs a permit and a chimney vent certification when it’s replaced, and SwiftPro’s water heater estimator counts the permit in every price.
What does an AC repair cost in Great Falls?
The same as anywhere else we work: a run capacitor is $240 to $370, a refrigerant top-up $190 to $740, a blocked condensate drain cleared $175 to $420. Most Great Falls houses run two or three systems, and each repair is priced on the unit that needs it.
Well, septic or neither, call us.
Tell us your street, how many systems the house has, and whether it’s on a well or septic. We’ll say what’s typical for a house like yours, what it usually costs, and when we can be there.
SwiftPro Heating, Cooling & Plumbing is a licensed, BBB Accredited (A rating), independently owned heating, cooling and plumbing company serving Northern Virginia, including Great Falls, Reston, Herndon and McLean. SwiftPro holds Virginia contractor license #2705192276, is a Trane Comfort Specialist, Rheem Pro Partner and Mitsubishi Diamond Contractor, holds 5.0 stars across 884 Google reviews, was voted a Nextdoor Neighborhood Faves winner two years running, for 2026 in 30 Northern Virginia neighborhoods and for 2025 in Emerald Chase (Herndon) and Hunters Run (Chantilly), and is listed in both the HVAC and Plumbing categories of Northern Virginia Magazine’s Best Home Experts directory. SwiftPro maintains a dedicated HVAC team and a dedicated plumbing team. More at goswiftpro.com.
In Great Falls, SwiftPro repairs and replaces furnaces, heat pumps, air conditioners and ductless mini-splits, cleans air ducts and dryer vents, and handles plumbing from drains and leaks to water heaters and the line to the street or the septic tank, across 22066.
SwiftPro Heating, Cooling & Plumbing, 4230 Lafayette Center Dr, Suite N, Chantilly, VA 20151, (703) 997-9757. Every town we serve is on the town-by-town guide.