Furnace and heating repair in Fairfax.
Furnace, heat pump and boiler repair in the City of Fairfax and the county side, priced before anybody opens a panel.
- Prices in writing, first
- Furnaces, heat pumps and boilers
- Dedicated HVAC team
Get your heating repair priced
Fairfax heats with gas, in houses on their third or fourth furnace.
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 is where Fairfax’s heat pumps are: 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.
What’s heating the houses across Fairfax.
Census figures for the owner-occupied homes in each place, and what that usually means for the heat.
| 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: electric heat or small 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. |
| 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: electric heat or small closet units. |
| Fair Lakes | 1998 | townhouses, about 3 in 10 | gas, about 7 in 10 | 1980s and 90s houses, most on their second furnace. |
| 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. |
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 heat here is a gas furnace, so most calls come down to the flame sensor, the igniter, the inducer motor or a pressure switch.
- Older houses often share one chimney between the furnace and the water heater, which matters the day either one is replaced.
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 heat is often electric or a small unit in a closet, and the building may control the flue and the gas line.
What furnace repair costs in Fairfax.
The same price book as the rest of our site. The diagnostic visit is about $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 visitabout $99
Often same-day, and we will tell you honestly when we can get there.
With Comfort+ membership, any service is 15% off, and a heating maintenance visit comes every fall.
What a failing furnace in Fairfax usually does.
A yellow, lazy burner flame
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.
It lights, then shuts off
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.
It won’t light at all
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.
What the county says about your heat in Fairfax.
Fairfax County
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.
How to pick the best furnace repair company in Fairfax.
Questions worth asking anybody who comes out, us included.
Will they check the chimney when the furnace changes?
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.
Will they price the part before they fix it?
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.
Do they look at the venting, not just the flame?
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.
Do they know when a repair isn’t worth it?
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.
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.
Very pleasant experience. Unfortunately the original heating system, that was brand new 56 years ago, is requesting retirement. A replacement unit is in consideration.
5.0 stars across 884 Google reviews. Read them on our reviews page.
Heating repair questions from Fairfax.
Why does my furnace start and then shut off?
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.
Is there a rebate for a new heating system in Fairfax?
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.
Why does my Fair Lakes furnace shut off on the coldest nights?
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.
How much does furnace repair cost in Fairfax?
The diagnostic visit is about $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.
Should I repair it or replace it?
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.
Furnace repair in the towns next door.
- Furnace repair in Oakton
- Furnace repair in Burke
- Furnace repair in Vienna
- Furnace repair in Annandale
- Furnace repair in Springfield
More from SwiftPro in Fairfax
Tell us what your heat is doing.
Call, or book online and pick a window. 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 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.