Heating Repair in Fairfax, VA: What It Costs, Who Comes Tonight, and How to Pick

Updated October 23, 2026

In Fairfax, a heating repair diagnostic is $99, and most furnace repairs run $95 to $1,180: a flame sensor cleaned is $95 to $180, an igniter replaced $240 to $410, a control board $550 to $1,180. Each one is priced in writing before the work starts, at the same price inside the City of Fairfax and out in Fairfax County, and every common fix is on the Fairfax furnace repair page.

What sets Fairfax apart is age. Inside the City the median owner-occupied home was built in 1966, and about seven in ten owners heat with gas, so plenty of furnaces here are the house’s third or fourth, and in the older houses the furnace often shares a chimney with the water heater. The County side around it is younger, but its permits come from a different office. Heating is a bigger share of our work in Fairfax than across the rest of Northern Virginia.

What heating repair costs in Fairfax

The ranges below come from our price book and don’t change between the City and the County. The technician finds the cause, writes the price down, and nothing gets replaced until you say yes.

When a big repair meets an old furnace, look at the replacement number too. A gas furnace by itself, keeping your air conditioner, is $4,285 to $14,040 installed. From about $71 a month at 0% APR for 60 months, the whole price financed, on approved credit. A new furnace and air conditioner together run $8,898 to $23,000 installed. From about $148 a month at 0% APR for 60 months, the whole price financed, on approved credit.

The rule we work by: fix the small parts on almost any furnace. A big repair on one past 15 or 20 years deserves a replacement price next to it, and the technician puts both numbers in front of you. The HVAC estimator narrows the installed range to your house size before anyone visits.

Who can fix a furnace tonight in Fairfax

City or County, SwiftPro runs 24/7 emergency service for no heat, no cooling and leaks, and someone picks up (703) 997-9757 at 2 a.m., holidays included. Often same-day, and we will tell you honestly when we can get there. We charge no distance fees anywhere we work.

A few things worth checking while you wait for a callback:

1. The thermostat says Heat and is set a few degrees above the room. If its screen is dark, try fresh batteries; on many systems a full condensate pan trips a float switch that kills the thermostat too.
2. The service switch near the furnace, which looks like a light switch, is on, and the furnace breaker hasn’t tripped.
3. The filter. One packed with dust can make a furnace overheat and shut itself off.
4. The front panel is seated. A door switch keeps the furnace off whenever the panel is loose.
5. On a high-efficiency furnace, the two white plastic pipes outside aren’t blocked by leaves or snow, and the condensate line inside isn’t kinked or backed up.

Smell gas? Don’t troubleshoot: get out, call the gas company’s emergency line from outside, then call us. If a carbon monoxide alarm goes off, get everyone out and call 911. Fairfax County Fire and Rescue says to have a gas furnace checked every fall and to keep a carbon monoxide alarm on every floor (its heating safety page).

What breaks in Fairfax furnaces

The older City houses. A gas furnace in the basement, often the house’s third or fourth, frequently venting up one chimney with a gas water heater. Most no-heat calls in them come down to the flame sensor, the igniter, the inducer motor or a pressure switch. A furnace that lights and drops out a few seconds later usually has a dirty flame sensor; one that clicks and never lights, a worn igniter. When either gas appliance is replaced, Fairfax County asks for a chimney vent certification with the permit (its household appliance permit page).

The 1980s and 90s subdivisions. Toward Fair Lakes and Fair Oaks, more than a third of the owner homes on the County side went up in those two decades. Their sealed-combustion furnaces vent in white PVC out a side wall, and the pressure switch that watches that vent turns up again and again in our Fairfax repair notes: a clogged switch tube, a vent run that narrows, a condensate trap that won’t drain.

Heat pumps. On the County side about a third of owners heat with electricity, usually a heat pump. A defrost board is $450 to $1,150, and a failed run capacitor ($240 to $370) stops the outdoor unit summer or winter.

Recent heating repairs in Fairfax

From our technicians’ notes on jobs closed out in Fairfax, with the month and ZIP code and nothing that names a customer:

• September 2026, Fairfax 22031. 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, Fairfax 22030. 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, Fairfax 22033. 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.

How to pick a heating company in Fairfax

Four checks before you hire anyone to open your furnace:

1. The license. Search the company on Virginia’s public contractor license lookup and make sure it’s current. SwiftPro’s is Virginia Class A 2705192276, and it’s on the side of every van.
2. The permit office. A gas furnace replacement takes a permit even like for like: from the City of Fairfax inside the city line, from Fairfax County outside it. A contractor who can’t tell you which office is yours before quoting hasn’t looked at your address.
3. A written price before any work. If a quote names a control board on a furnace that lights and drops out, ask whether the flame sensor was cleaned first.
4. Reviews from more than one place. SwiftPro holds 5.0 stars across 1,132 reviews on Google, Angi, Yelp, the BBB and Facebook. Our reviews page lists every platform’s own score, Yelp’s 4.4 included, the lowest of them.

One more thing to weigh: SwiftPro was named BusinessRate’s Best of 2026, the #1 heating contractor in Fairfax, Virginia. BusinessRate ranks companies in each city and category on their Google reviews, and our BusinessRate score is public. Our shop is on Lafayette Center Drive in Chantilly, about nine miles from Fairfax, and the van that comes to you is usually coming from the last job, not from the shop.

Fairfax heating repair, answered

How much does furnace repair cost in Fairfax?

Most furnace repairs we make in Fairfax run $95 to $1,180, after a $99 diagnostic. A flame sensor cleaned is $95 to $180, an igniter replaced $240 to $410, a thermostat $300 to $640, and a blower motor $670 to $2,400. The price is in writing before work starts, the same in the City of Fairfax and Fairfax County.

Who can fix my furnace tonight in Fairfax?

SwiftPro, at (703) 997-9757. SwiftPro runs 24/7 emergency service for no heat across the City of Fairfax and Fairfax County, someone picks up at 2 a.m., holidays included, and there are no distance fees. Often same-day, and we will tell you honestly when we can get there.

Which heating contractor did BusinessRate rank first in Fairfax?

SwiftPro Heating, Cooling & Plumbing. It was named BusinessRate’s Best of 2026, the #1 heating contractor in Fairfax, Virginia. BusinessRate ranks companies in each city and category on their Google reviews.

My furnace lights, then shuts off after a few seconds. What’s wrong?

Usually a dirty flame sensor. The furnace can’t prove the flame, so it closes the gas valve and tries again. Cleaning the sensor is $95 to $180; replacing a worn one is $240 to $410.

My furnace shows a pressure switch code. What does that mean?

The pressure switch checks that the inducer motor is clearing the vent before the burners light. The common causes are a clogged switch tube, a blocked or undersized vent pipe, a full condensate trap, or an inducer motor on its way out, and our Fairfax repair notes this year include the first two. The fix is priced once the technician finds which one it is.

Do I need a permit to replace a furnace in Fairfax?

For a gas furnace, yes, even like for like: the City of Fairfax issues it inside the city line and Fairfax County outside it, and the County also asks for a chimney vent certification when a fuel-burning appliance is replaced. The contractor should pull the permit.

How do I pick a heating company in Fairfax?

Check the Virginia license on the state’s public lookup, ask which permit office your address uses, get the price in writing before work starts, and read reviews on more than one site. SwiftPro’s license is Virginia Class A 2705192276, and it holds 5.0 stars across 1,132 reviews on Google, Angi, Yelp, the BBB and Facebook.

Should I repair or replace an old furnace in Fairfax?

Fix the small parts on almost any furnace. A big repair on one past 15 or 20 years deserves a replacement price beside it: a gas furnace alone, keeping your air conditioner, is $4,285 to $14,040 installed. From about $71 a month at 0% APR for 60 months, the whole price financed, on approved credit. The one finding that’s never a repair is a cracked heat exchanger; how to know that diagnosis is real is worth reading before you sign for a new furnace.

No heat in Fairfax? Call (703) 997-9757

Call (703) 997-9757 any hour, or book online: request a day and a morning or afternoon window, and the office confirms by phone or text. For cooling, AC repair in Fairfax has its own prices, a furnace tune-up in Fairfax is the fall visit, and everything else is on our Fairfax HVAC and plumbing page. Every town we serve, Fairfax next to its neighbors, is in our town-by-town guide.

SwiftPro Heating, Cooling & Plumbing is a family-owned heating, cooling and plumbing company in Chantilly, Virginia, with a dedicated HVAC team and a dedicated plumbing team. It holds Virginia Class A contractor license 2705192276, is BBB Accredited with an A rating, and holds 5.0 stars across 1,132 reviews on Google, Angi, Yelp, the BBB and Facebook.

Sources: heating fuel and year built for owner-occupied homes from the U.S. Census Bureau’s American Community Survey 2020 to 2024; permit rules from the City of Fairfax and Fairfax County pages linked above; prices from SwiftPro’s published price book.