Professional gas furnace repair for Leesburg and Loudoun County homes.
Most Loudoun County homes heat with natural gas or propane, and gas furnaces fail in predictable ways: worn igniters, dirty flame sensors, sticking gas valves. Our technicians test the full ignition sequence to find the failed step, then repair it. Call (571) 561-3454 for gas furnace diagnosis in Leesburg.
Gas furnaces light in a strict sequence: the thermostat calls, the inducer fan clears the chamber, the igniter glows or sparks, the gas valve opens, the flame sensor confirms fire. If any step fails, the furnace locks out rather than dumping unburned gas. That lockout is the furnace protecting you, but it leaves you cold.
Hot surface igniters are the single most replaced gas furnace part. They glow white-hot thousands of times and eventually crack. Flame sensors get coated with oxidation and stop sensing the flame they are sitting in. Gas valves stick after years of service. Each has a distinct signature a technician reads in minutes.
Every gas furnace visit includes combustion safety checks. The technician looks for cracked heat exchangers, blocked vents, and improper flame color, all of which can produce carbon monoxide. A yellow, lazy flame instead of a crisp blue one is a warning sign worth investigating.
If your carbon monoxide detector ever sounds, leave the house and call the fire department first, then call us. Do not reset the detector and assume it was a false alarm.
Much of Leesburg runs on natural gas, but propane serves homes beyond the gas mains, especially toward Purcellville, Hamilton, and the rural routes. Propane furnaces need correct orifice sizing and pressure settings for the fuel. A furnace converted between fuels without proper setup burns dirty and soots the heat exchanger.
When you call, mention which fuel your home uses. It changes which parts the technician loads and which tests come first.
A gas furnace that lights and then drops the flame is almost always failing at the flame-proving step. The flame sensor rod sits in the burner flame and tells the gas valve it is safe to stay open. When oxidation coats the rod, it insulates the sensor from the flame it is sitting in, so the valve closes and the furnace tries again.
Older standing-pilot furnaces use a thermocouple for the same job, and a weak thermocouple produces the same symptom: pilot lights, pilot drops. Modern electronic-ignition units can also lose flame from a weak igniter that lights inconsistently or a gas valve that sticks after years of service.
If your furnace attempts ignition three times and then locks out, do not keep resetting it. The lockout exists to prevent repeated ignition attempts without a confirmed flame. Call (571) 561-3454 and describe the pattern; the fix is usually a cleaning or a single part.
While waiting for service, avoid opening the furnace cabinet or adjusting the gas valve yourself. Gas components, manifold pressure settings, and combustion air requirements are calibrated as a system, and well-meant adjustments can create the very unsafe conditions the lockout was preventing. Note what you observed, the number of ignition attempts, any unusual smells, and leave the rest to the technician.
Once a year, before heating season. A proper gas furnace service includes burner inspection and cleaning, flame sensor cleaning, heat exchanger inspection, gas valve and manifold pressure checks, venting inspection, condensate drain clearing on high-efficiency units, and carbon monoxide testing at the furnace and supply registers.
Skipped service lets small problems compound. Dirty burners soot the heat exchanger, a weakening igniter cracks on the coldest night, a clogged condensate drain shuts down a condensing furnace, and a sticking gas valve gets worse until it sticks closed. Most January no-heat calls were visible as wear in October.
Annual service also keeps the manufacturer warranty intact, since most warranties require documented professional maintenance. Schedule in September or October, when there is time to fix what the visit finds.
Between visits, the best thing a homeowner can do is keep the air filter clean and the area around the furnace clear. A starved filter forces the burners to run hotter, and stored items blocking combustion air intake can disturb the flame pattern the technician just calibrated. Those two habits cost almost nothing and meaningfully extend the interval between service findings.
Straight answers before you call.
Describe what your furnace is doing and we will point you to the right next step.
Call (571) 561-3454That is the ignition lockout sequence. The furnace attempts ignition, fails to prove flame, and locks out for safety. The cause is usually the igniter, flame sensor, or gas supply.
A healthy gas flame burns blue. Persistent yellow tipping can mean incomplete combustion, which deserves a professional look promptly.
With regular maintenance, most gas furnaces serve 15 to 20 years. Frequent repairs in the later years usually mean replacement deserves a conversation.
It is a delicate part and the furnace cabinet contains gas and high voltage. Leave it to a technician with the right tools and testing equipment.
The furnace starts, runs briefly, and shuts off repeatedly. Common causes include overheating from restricted airflow, a faulty flame sensor, or an oversized unit.
No-heat emergencies diagnosed and repaired fast, day or night.
Repair for electric furnaces, air handlers and heat strips.
Seasonal tune-ups that keep the furnace safe and reliable.
New furnace installation sized and set up for Loudoun County homes.
Call now and describe what is happening. We will take it from there.
Call (571) 561-3454