Open 24/7 for emergencies
The diagnostic visit is $99, and a flame sensor cleaned is $95 to $180 from our published price book.
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Furnace, heat pump and boiler repair in the City of Fairfax and the county side, priced before anybody opens a panel.
5.0 stars across 1,132 reviews
Two of our technicians in a Northern Virginia utility room, between the furnace and the water heater.
Licensed and insuredVirginia Class A contractor #2705192276
24/7 emergency serviceOften same-day, and we will tell you honestly when we can get there.
Our own HVAC installersA dedicated heating and cooling team, separate from our plumbers
Price in writing firstYou see every option priced before anything is ordered
What it costs
The same price book as the rest of our site. The diagnostic visit is $99, and the tech prices the repair before starting it.
Flame sensor cleaned
$95 to $180
Igniter or flame sensor replaced
$240 to $410
Blower wheel pulled and cleaned
$300 to $440
Thermostat replaced
$300 to $640
Control board
$550 to $1,180
Blower motor
$670 to $2,400
Repair diagnostic visit
$99
Often same-day, and we will tell you honestly when we can get there.
With Comfort+ membership, $20 a month or $199 a year, the diagnostic visit is included, any service is 15% off, and a heating maintenance visit comes every fall.
Recent work
What our technicians found and fixed on visits in Fairfax, from their notes on each job.
September 2026
An emergency no-heat call: the furnace’s exhaust flue was restricted, and reaching the section that needed changing meant moving the water heater beside it first.
April 2026
A gas furnace stopped on an E3 code, its pressure switch stuck open. The switch’s tubing was clogged; cleared, the furnace ran again, with an inducer cleaning written up as the lasting fix.
March 2026
A furnace cutting out on code 32, the pressure switch opening because its PVC exhaust narrowed to an inch and a half. The fix written up: 2 inch pipe the whole way out.
What’s different in Fairfax
In the City of Fairfax and Mantua, most homeowners heat with gas, in houses from the 1960s. The furnace is down in the basement or off the utility room, usually the third or fourth the house has owned, still pushing air through the original ductwork and venting up the original chimney.
Kings Park West leans toward heat pumps: close to half the homeowners there heat with electricity. Fair Lakes and Fair Oaks are younger, mostly 1990s, and most of their first furnaces have been replaced once already.
Heating is a bigger share of our Fairfax work than in most towns we serve, and replacing a gas furnace here takes a permit even like for like: the City of Fairfax issues it inside the city line, Fairfax County outside it.
Merrifield is the newest part of the Fairfax address: more than half of it went up after 2000, mostly in condo and apartment buildings, so the heat there is usually a heat pump or a compact gas furnace in a closet. Inside the city line a few houses still heat with oil, and the City of Fairfax has its own fire department and its own permit office, so there it’s the City’s inspectors and firefighters, not the county’s.
Neighborhood by neighborhood
Census figures for each place, and what that usually means for the heat. Median year built and heat count owner-occupied homes only.
| Place | Median home built | Most homes are | Heated with | What the heat usually is |
|---|---|---|---|---|
| Fair Oaks | 1995 | condo and apartment buildings, about 5 in 10 | gas, about 6 in 10 | Condo and apartment buildings: gas or electric, in compact closet units. |
| City of Fairfax | 1966 | single-family houses, about 5 in 10 | gas, about 7 in 10 | Gas furnaces in older houses, often sharing a chimney with the water heater. |
| Fairfax Station | 1982 | single-family houses, about 9 in 10 | gas, about 5 in 10 | 1980s and 90s houses, most on their second furnace. |
| Kings Park West | 1976 | single-family houses, about 7 in 10 | gas, about 5 in 10 | Gas furnaces in older houses, often sharing a chimney with the water heater. |
| Merrifield | 1990 | condo and apartment buildings, about 6 in 10 | gas, about 6 in 10 | Condo and apartment buildings: gas or electric, in compact closet units. |
| Fair Lakes | 1998 | townhouses, about 3 in 10 | gas, about 7 in 10 | 1980s and 90s houses, most on their second furnace. |
| Long Branch | 1968 | single-family houses, about 9 in 10 | gas, about 7 in 10 | Gas furnaces in older houses, often sharing a chimney with the water heater. |
| Mantua | 1968 | single-family houses, about 7 in 10 | gas, about 7 in 10 | Gas furnaces in older houses, often sharing a chimney with the water heater. |
By the numbers
From the Census Bureau’s 2020 to 2024 survey. Median year built and heat count owner-occupied homes only.
Most of the Fairfax Station Census place, in the table, has Fairfax mail, so it counts here.
What you’d notice
Gas burners should burn mostly blue and steady. A flame that’s yellow and wavering usually means dirty burners or not enough air for a clean burn. On a 1960s Fairfax furnace sharing a chimney with the water heater, that’s a call for this week, not next season.
The burners fire and go out a few seconds later, over and over. That’s usually a dirty flame sensor, and cleaning it takes about ten minutes.
No glow, no flame. A cracked igniter is the usual part, and on a high-efficiency furnace a clogged condensate line can stop it cold too.
Safety and paperwork
Fairfax County Fire and Rescue says to have the heating system cleaned and checked by a professional every year, and to keep anything that burns at least three feet from the furnace and the water heater. Source.
Fairfax County Fire and Rescue names a faulty gas furnace or water heater as a carbon monoxide source, says to have gas appliances inspected every fall, and to put a CO alarm on every floor. Source.
Our Virginia Class A contractor license, 2705192276, is on the side of the van.
Choosing who fixes it
Questions worth asking anybody who comes out, us included.
In a 1960s Fairfax house the furnace and water heater often share one chimney. Change one and the other’s venting changes, which is why Fairfax County asks for a chimney vent certification whenever a gas appliance is replaced.
Flame sensors, igniters and control boards all have a going rate. A tech who can’t tell you the number before starting is asking you to find out afterwards.
Getting the burners lit is half a heating call. Ask whether they check the flue and test for carbon monoxide while the panel’s open.
A big repair on a furnace past 15 or 20 years deserves a replacement price next to it. A good tech puts both numbers in front of you and lets you choose.
Two of our crew going over a work order before the day's calls.
From our Google reviews
5.0 stars across 1,132 reviews. Read them on our reviews page.
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.
Very pleasant experience. Unfortunately the original heating system, that was brand new 56 years ago, is requesting retirement. A replacement unit is in consideration.
Questions
Most often a dirty flame sensor: the burners light, the sensor can’t prove the flame, and the furnace shuts the gas off to be safe. Cleaning it is $95 to $180; if the sensor or the igniter needs replacing, $240 to $410.
The federal tax credit ended December 31, 2025. If you’re on Washington Gas, the utility pays toward a dual fuel system, a heat pump with a gas furnace as backup; our dual fuel guide has the current amounts and who qualifies.
In a 1990s Fair Lakes or Fair Oaks house whose first furnace was replaced with a high-efficiency one, the condensate line is the usual suspect. That furnace makes water, and if the line clogs, or freezes where it runs outside, a safety switch stops the burners. Clearing it is a small repair; re-routing a line that keeps freezing is a bigger one.
The diagnostic visit is $99. A flame sensor cleaned is $95 to $180; an igniter or flame sensor replaced, $240 to $410; a control board, $550 to $1,180; a blower motor, $670 to $2,400.
Fix the small parts on almost anything. Before a big repair on an old furnace, look at the replacement number: a furnace alone, keeping the air conditioner you have, runs $4,285 to $14,040 installed, and the HVAC estimator gives your number in about a minute. From about $71 a month at 0% APR for 60 months, the whole price financed, on approved credit.
Ready when you are
Call, or send the form at the top. The tech prices the repair from the book before starting, and if the furnace is at the end of its life you’ll hear that first.
SwiftPro Heating, Cooling & Plumbing
4230 Lafayette Center Dr N, Chantilly, VA 20151
44679 Endicott Dr, Suite 211, Ashburn, VA 20147
Virginia Class A contractor license #2705192276
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 1,132 reviews on Google, Angi, Yelp, the BBB and Facebook. SwiftPro maintains a dedicated HVAC team and a dedicated plumbing team.
From SwiftPro Heating, Cooling & Plumbing in Chantilly. Housing figures are the Census Bureau’s American Community Survey, 2020 to 2024, for each place named; permit, water and sewer facts link to each office’s own page and were checked in September and October 2026.