Oakton sits between Vienna and Fairfax and shares housing stock with both, which means the town name on your mail tells a contractor almost nothing useful. The decade your house was built tells them everything.
Three vintages show up on our Oakton calls, and each fails in its own way.
Three vintages, three sets of problems
1960s and 1970s ranches, splits and colonials. One gas furnace, replaced two or three times in the same basement corner, still connected to the original ductwork and one hallway return. The equipment is modern and the distribution is not, so the symptoms get blamed on the newest box in the house.
1980s and 1990s houses. Larger, often two systems, sealed combustion furnaces venting out a side wall. Most are on their first or second furnace and sitting in the twenty to thirty year band where parts start asking for attention.
Newer and rebuilt houses on larger lots. Two or three zoned systems, multiple thermostats, and the failure mode where a system serving a guest wing is dead for weeks before anybody notices.
What breaks
It lights, runs a few seconds, shuts off, tries again. Flame sensor. A film of oxide stops it confirming the flame and the board closes the gas. $95 to $180 to clean, and the most common no-heat call we run anywhere.
Clicking with no flame. Hot surface igniter, $240 to $410. A wear item, not a verdict.
Short cycling, and a cold room at the far end. In an older house that is usually an oversized furnace on undersized ductwork, not a fault. Somebody matched the old unit’s BTU rating instead of measuring the house. No repair fixes it; sizing the next one properly does.
Runs fifteen minutes and shuts down. Overheating on restricted airflow. Filter first, then the blower wheel at $300 to $440.
One zone warm, one cold on the same system. A zone damper or its motor in a newer house, not the furnace.
Water near a high efficiency furnace, or one that will not start. Condensate trap, $175 to $420.
One cold radiator or clanking. If you are in one of the older houses that still has a boiler, that is air in the loop. Bleed it. Routine.
Common Furnace Repair Issues in Oakton Homes
- Diagnostic visit: about $99.
- Flame sensor cleaned $95 to $180; igniter or sensor replaced $240 to $410.
- Condensate drain or trap $175 to $420. Thermostat $300 to $640.
- Blower wheel cleaned $300 to $440. Blower motor $670 to $2,400.
- Control board $550 to $1,180. Inducer motor about $1,950.
- Heat pump defrost board $450 to $1,150.
- Cracked heat exchanger: not a repair at any price. Here is why.
Full furnace list with symptoms here.
Replacing
Past fifteen years, if the repair is more than a third of a replacement, replace it. Under ten, repair almost every time.
A furnace alone runs $4,498 to $12,300 installed; a furnace and air conditioner together $8,898 to $23,000 by system size. In an older Oakton house, insist on a measurement rather than a match to the outgoing sticker, and get somebody to look at the return while they are there. In a multi-system house, replace by system rather than by house unless everything went in together.
Washington Gas is paying $500 on a furnace at 95.1 to 96.9 percent efficiency and $700 at 97 and up, through contractors in its network. The federal tax credit ended for anything placed in service after December 31, 2025.
The estimator gives you the installed range for your system size in about two minutes with no phone number.
October list
Run every system for an hour, including any that serve rooms you rarely use. Change every filter. And put a carbon monoxide alarm on each sleeping floor, because Virginia requires them in new construction with fuel burning appliances and has no retrofit rule for the older houses.
SwiftPro repairs heating systems across Oakton. Call (703) 997-9757, book online, or start at the Fairfax County heating repair page.
