Heating, cooling and plumbing in Herndon, on both sides of the town line.
Inside the Town of Herndon, the Town runs your water, your sewer and your permits. Outside it, Fairfax County does. Here’s what that changes at your house.
- Prices in writing, first
- Dedicated HVAC and plumbing teams
- Virginia license #2705192276
Get your price in writing
A 1970s town with 1980s subdivisions all around it.
Inside the town limits, the 1970s are the biggest building decade. Cross into Franklin Farm, Floris or Dranesville and it’s mostly the 1980s and 90s.
The Town mixes its housing: a bit over four in ten homes are single-family houses, about a quarter are townhouses and about a quarter are in condo and apartment buildings. About six in ten owners heat with electricity, which usually means a heat pump, and close to four in ten homes are rented.
The county side is mostly single-family streets from the 1980s. Franklin Farm splits about evenly between heat pumps and gas furnaces, Dranesville leans electric and Floris leans gas. McNair, along Sunrise Valley Drive, is the young one: mostly built since 2000, mostly condo and apartment buildings, and about three in four homes rented.
A house from the 1970s or 80s has usually replaced its heat pump or furnace at least once while keeping the ductwork it was built with, and plenty were plumbed in the years grey polybutylene supply pipe was going in.
Heat pumps, furnaces, pipes and tanks.
A dedicated HVAC team and a dedicated plumbing team, both working out of our shop on Lafayette Center Drive in Chantilly.
Heating
With about six in ten town owners on electric heat, a no-heat problem inside the town is more often a heat pump stuck on its backup strips than a gas furnace that won’t light. The furnace repair link below prices the common repairs for both, and the estimator prices a replacement.
Cooling
A heat pump’s outdoor unit cools in July and heats in January, so a summer problem on one is often next winter’s problem too. Duct cleaning and dryer vent cleaning each have a page of their own below, and a townhouse dryer vent here can run a long way to reach the outside.
Plumbing
Houses from the late 1970s to the mid 1990s fall in the polybutylene years, so it’s worth knowing what your supply pipe is made of. Water heaters come next: the water heater estimator prices a replacement, permit included, in about a minute.
One price list, town or county.
Our prices don’t change at the town line, and you get the number in writing before any work 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 come from the price book behind our plumbing page and our AC repair page. Swapping a water heater? The water heater estimator gives you yours, permit included.
Thinking about a new heat pump or furnace? The HVAC estimator gives the installed range for your house size before anybody visits.
The town line decides three things.
Your water
Inside the town, the Town of Herndon is your water company. It buys treated water from Fairfax Water, and its 2025 report says most of it comes from the Corbalis plant on the Potomac, which ran 4.1 to 10.8 grains per gallon that year. The county side is on Fairfax Water directly.
Reports: Town of Herndon (Fairfax Water’s water), 4.1 to 10.8 gpg; Fairfax Water, 3 to 10.8 gpg.
Your permit office
Inside the town limits, the Town of Herndon’s Building Inspections office issues permits and inspects; outside them, Fairfax County does. On either side a gas furnace or gas water heater swap needs a permit, and under the state code an electric one in the same spot doesn’t.
Permit pages: Town of Herndon or Fairfax County.
Your sewer line
In the town, a house or townhouse owner keeps the lateral sound out to the right-of-way line and the Town takes it from there to the main, though a clog anywhere along it is still the owner’s to clear. In Fairfax County the homeowner owns the whole lateral, the stretch under the street included.
Sources: Herndon Town Code 74-267 and Fairfax County Code 65-6-5 and the Town’s 2025 water quality report.
What our customers say.
I reached out to them after 6 pm when our AC unit stopped cooling the house and they had someone out the next morning.
I placed an emergency call for pipes that had frozen and burst in my bathroom in the very early morning.
They gave me a 4 hour window but were out at the property within the hour.
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.
The Town, and the county streets around it.
Inside the town: downtown along Elden Street and the neighborhoods out to Herndon Parkway. On the Fairfax County side: Floris and Franklin Farm in 20171, McNair along Sunrise Valley Drive, and Dranesville in 20170. Next door:
Herndon questions.
Am I in the Town of Herndon or in Fairfax County?
A Herndon mailing address can be either. The Town is its own government inside Fairfax County, with its own water, sewer and permit office, while Floris, Franklin Farm, McNair and Dranesville carry Herndon addresses and are Fairfax County. The quickest check is your water bill: inside the town it comes from the Town of Herndon, and on the county side from Fairfax Water.
Will the Town of Herndon credit my water bill after a leak?
It can, once every five years, for owners. Fix an inside or underground leak within 10 days of finding it, then send the Town the contractor’s invoice describing the repair, dated to match. If it’s approved, an inside leak is credited for 66 percent of the extra water and an underground leak for all of it. A faucet left running doesn’t count. The rules are on the Town’s leak adjustment page.
Can my sump pump drain into the sewer in the Town of Herndon?
No. Town Code bars a sump pump, downspout or areaway drain from emptying into the sanitary sewer, directly or indirectly, and the Town gives an owner 30 days from written notice to disconnect one. A plumber can reroute it to discharge outside instead.
Do you fix heat pumps in Herndon?
Yes, and inside the town they’re the usual heat: about six in ten owners heat with electricity. A heat pump runs all year, so SwiftPro checks the heating parts on a summer call and the cooling parts on a winter one, and prices the repair from the book before starting it.
Where is SwiftPro’s shop?
SwiftPro Heating, Cooling & Plumbing is at 4230 Lafayette Center Drive, Suite N, Chantilly, VA 20151, about six miles from the middle of Herndon, and the number is (703) 997-9757. The same crews work inside the town and on the county side, at the same prices.
Tell us your Herndon street.
Say whether you’re inside the town or on the county side, if you know. We’ll tell you what’s typical for houses 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 Herndon, Reston, Chantilly and Fairfax. 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 Herndon, SwiftPro repairs and replaces heat pumps, furnaces, air conditioners and ductless mini-splits, cleans air ducts and dryer vents, and handles plumbing from drains and leaks to water heaters and sewer lines, inside the Town of Herndon and on the Fairfax County side.
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.