Most of Bristow was built this century, which makes it the town where we are most likely to tell somebody their furnace is fine.
That is worth saying plainly, because the flip side is real: a house with fifteen year old equipment is exactly the house a high pressure sales visit targets. If somebody has told you a system this young needs replacing, slow down and ask which part failed and what it costs to fix.
What is in these houses
Gas furnaces with central air, sealed combustion, PVC venting out a side wall, in houses from the 2000s onward. Two systems in the larger ones. Heat pumps in a share of the townhouses. No boilers.
Equipment of this vintage is generally well made and, when it was installed correctly, runs a long time. What fails first is small and cheap.
What actually goes wrong at fifteen to twenty years
It lights, runs a few seconds, shuts off, tries again. Flame sensor. The metal rod that confirms the flame builds a film of oxide and stops passing its signal, so the board shuts the gas as a safety. Cleaning it is $95 to $180 and takes ten minutes. This is far and away the most common no-heat call we run, and it is not a reason to replace anything.
Clicking with no flame. Hot surface igniter, $240 to $410. A wear part. Ceramic gets brittle and cracks. Also not a reason to replace a furnace.
Water on the floor, or the furnace will not start. The condensate trap. A high efficiency furnace makes water when it runs, and when the drain clogs it refuses to fire on purpose. $175 to $420.
Runs and quits after fifteen minutes. Overheating, which means airflow, which means the filter or the blower wheel. Cleaning the wheel is $300 to $440.
A squeal or grind from the blower. Blower motor, $670 to $2,400. This is the first repair on the list that is genuinely expensive, and on a fifteen year old furnace it is still usually worth doing.
Before you pay for anything, check the warranty
On equipment this age it is often still covered. Most major brands give ten years on parts if the unit was registered shortly after installation, which is 90 days for Carrier and Rheem and 60 for Trane and Goodman. Unregistered, it usually drops to five. None of the standard warranties include labor, so a covered repair still costs something, just far less than the full price.
The model and serial number are on a label inside the furnace door. One phone call with those settles it, and it can be the difference between a $99 visit and a four figure one.
Repair prices
- 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. Capacitor $240 to $370.
The one thing that is not a repair
A cracked heat exchanger is replacement at any age, because it is the metal wall between the flame and the air you breathe. The industry guideline is blunt about it: any split, crack or hole and the exchanger or the furnace is replaced.
It is also the diagnosis most worth a second opinion on a young furnace, because it is the one that ends with a replacement quote. A real diagnosis involves a visual inspection and combustion readings, not a hunch. Here is how to tell whether the diagnosis is real, and if you want us to look, the second opinion is free.
When replacement does make sense
Under ten years, repair, almost without exception. Past fifteen, if the repair is more than a third of a replacement, replace. Most of Bristow is in the first bracket or the early part of the second.
When you do get there, a furnace alone runs $4,498 to $12,300 installed and a furnace and air conditioner together $8,898 to $23,000 by system size. Because both went in with the house here, doing them together beats two jobs two years apart. Washington Gas pays $500 on a furnace at 95.1 to 96.9 percent efficiency and $700 at 97 and up, through contractors in its network.
The estimator gives you the installed range for your size in about two minutes, no phone number, so you have a published figure to hold any quote against.
October list
Run the heat for an hour and listen to the first two minutes: inducer, igniter, burners, blower, in order, no hesitation. Change the filter. Write down the model and serial number from inside the furnace door. And check the carbon monoxide alarms, because the ones installed with these houses are reaching the end of their ten year service life.
SwiftPro repairs heating systems across Bristow and western Prince William County. Call (703) 997-9757 or book online.
