From the hallway, a furnace that will not heat looks the same no matter what broke. Inside the cabinet, though, the sequence is strict: inducer on, pressure switch closed, igniter glowing, gas valve open, burners lit, flame proven, and finally the blower moving heat through the ducts. Most of the diagnosis comes down to finding the broken link. In Reston homes, it tends to be the same handful of culprits: a flame sensor coated in oxide, a hot surface igniter cracked by thermal cycling, a pressure switch held open by a tired inducer or a plugged condensate trap, or a control board with a burned relay.
Reston HVAC repairs furnaces by testing the sequence, not guessing at it. Our experienced technicians verify each stage with a meter rather than a hunch: igniter resistance, flame signal in microamps, pressure switch operation against actual inducer draft, gas valve voltage, and blower and capacitor health. Every visit includes the safety fundamentals on a fuel-burning appliance: the heat exchanger inspected, connections leak-tested, and draft confirmed, because the difference between a furnace problem and a furnace hazard is not visible from the thermostat. We measure temperature rise against the data plate before we leave so the fire and the airflow are matched the way the manufacturer intended.
We work on natural gas, propane, and electric furnaces from every major brand, both conventional 80 percent units and condensing high-efficiency models with their traps, drains, and dual pressure switches. The truck stock covers the parts that actually fail: igniters, flame sensors, pressure switches, capacitors, inducer assemblies, and blower motors, so most repairs finish in one trip. For furnace repair anywhere in Reston, call (571) 741-3122 and we will get the burners lit today.
Cooling trouble instead? See AC Repair in Reston.
How Much Does Furnace Repair Cost in Reston?
Most furnace repairs in Reston cost between $150 and $600. Ignition and sensor problems are usually the least expensive, while blower motors, control boards, and heat exchangers cost more. Every furnace repair starts with a real diagnosis and a clear price.
| Repair | Typical cost | What it usually means |
|---|---|---|
| Flame sensor cleaning or replacementFurnace lights, then shuts off within seconds | $80–$250 | Burners light but cut out almost immediately |
| Hot surface igniter replacementNo ignition; one of the most common winter failures | $150–$400 | No ignition; one of the most common winter failures |
| Draft inducer motorStartup fan fails, furnace won't fire | $400–$1,000 | Startup fan fails, furnace won't fire |
| Blower motorBurners run but little or no air comes out of the vents | $400–$1,500 | Burners run but little or no air comes out of the vents |
| Control boardErratic behavior, error codes, or no response at all | $300–$700 | Furnace won't respond to the thermostat |
| Gas valve replacementValve fails to open, so the furnace never lights | $250–$700 | Valve fails to open, so the furnace never lights |
Ranges are typical for these repairs; you get an exact quote before any work starts.
What Moves the Cost Up or Down
- The age and efficiency of the furnace, since high-efficiency models use more specialized parts
- Whether a cracked heat exchanger is found, which usually means replacement rather than repair
- Same-day or after-hours service versus a planned visit
- How easy the furnace is to reach
If your furnace is past 15 to 20 years old or the repair is a major one, we'll give you repair and replacement prices side by side. Call (571) 741-3122 to get your price.
Warning Signs for Furnace Repair
The sooner you notice these red flags, the easier and cheaper the problem is to resolve. Here are the most common indicators that it's time to call a professional:
- A pilot or burner flame that is lazy yellow instead of crisp blue
- A fan that keeps running while the registers blow cool air
- Repeated shutdowns just seconds after the burners light
- A furnace that shuts off every few minutes before the house warms up
- Soot, rust, or moisture near the furnace cabinet or vent pipe
- The furnace clicks and glows but the burners never light
- Booming or banging at light-off from delayed ignition
- Squealing or grinding from the blower compartment
Don't Wait for a Total Failure
A failing capacitor, clogged condensate drain, or dirty flame sensor rarely fixes itself and usually gets more expensive to address the longer it runs. Don't wait, get Reston HVAC on the phone at (571) 741-3122 and we'll take a look right away.
Furnace Repair Issues? We Can Help.
Call our expert team for pricing today.
Call (571) 741-3122 TodayFurnace Repair FAQ
The Benefits of Professional Furnace Repair
Gas, open flame, high voltage, and a flue share one cabinet in a furnace, and the most dangerous failure is the one you cannot see: a damaged heat exchanger that lets combustion gases into the air the blower circulates. Every morning that delayed ignition keeps booming at startup, that exchanger takes more stress. The diagnostic side has its own pitfalls. When a furnace trips its high limit, the switch itself may be bad, or the furnace may be protecting itself from a clogged filter or a failing blower. Swapping the switch in that second case removes a safety device and leaves the actual problem in place.
Our experienced technicians look at every symptom in the context of the whole furnace. We measure flame signal instead of assuming it, which keeps us from replacing a healthy sensor while a cracked igniter or weak gas valve goes unnoticed. Draft is confirmed at the pressure switch and at the flue. Temperature rise is checked against the data plate, catching airflow problems before they shorten the life of the heat exchanger. The gas side is leak-tested with instruments, never with a quick sniff. What you get is a furnace proven safe over a full cycle, plus an honest opinion if the unit is getting close to the point where replacing it beats repairing it again.
Our Furnace Repair Process
Every visit follows a step-by-step method refined over years of hands-on experience. Here's exactly how the furnace repair process unfolds:
Step-by-Step Diagnosis
We watch the furnace's startup sequence and measure at every stage: inducer draft, pressure switch, igniter resistance, flame signal, and gas valve operation, to find exactly where it breaks.
Safety Inspection
The heat exchanger is inspected, gas connections are leak-tested, and flue draft verified on every visit. A furnace repair that is not proven safe is not finished.
Same-Visit Repair
Igniters, flame sensors, pressure switches, capacitors, and motors ride on the truck, so most furnaces are lit and heating again before we pack up.
Complete Verification
Before we leave, the furnace runs full cycles while we check temperature rise against the data plate, listen for clean, quiet ignition, and test each limit and safety control.
Not Sure What You Need?
Our experienced technicians can assess your situation and recommend the best solution.
Call (571) 741-3122 TodayHow to Prevent Furnace Repair Problems
A little routine maintenance goes a long way toward avoiding a mid-season breakdown. Follow these tips from our experienced technicians:
- Keep a working carbon monoxide alarm on every level of the home and check it each month
- Put in a fresh filter monthly through the heating season, the cheapest protection your furnace can get
- Give the furnace room to breathe, since a crowded utility space starves the burners of air
- Notice how the furnace sounds at startup, because a quiet light-off is healthy and a boom is not
- Have the furnace checked every autumn, while a weak igniter or fouled sensor is still an easy fix
- On high-efficiency models, keep the condensate trap and drain line clear and draining
- Clear boxes, lint, and above all chlorine-based cleaners out of the furnace area
Should You DIY or Call a Pro?
Online tutorials may help in a pinch, yet lasting repairs and code-compliant installations usually depend on professional methods and trained technicians. Consider the following comparison:
| Factor | DIY Attempt | Professional Service |
|---|---|---|
| Exchanger Cracks | No way to see a crack from outside | Checked every time we open the unit |
| Ignition Problems | New igniter installed on a hunch | Igniter, sensor, and valve each metered |
| Gas Safety | Connections judged by smell | Every fitting checked with a detector |
| Limit Trips | A safety device jumpered out | Root cause of overheating corrected |
| Blower Setup | Fan speed never checked | Temperature rise set to the data plate |
| Final Check | One good start and done | Complete cycles tested before we leave |
Talk to a Furnace Repair Expert
Don't let a failing system get worse. Call Reston HVAC now for prompt, professional service.
Get Help: (571) 741-3122Where We Provide Furnace Repair
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