Furnace Ignitor & Thermocouple Repair in Plano, TX
Don't let a cracked ignitor or oxidized flame sensor leave your family freezing. Our certified Plano heating technicians carry universal silicon nitride hot surface ignitors, thermocouples, and electronic ignition modules for instant same-day repair.
Signs Your Plano Furnace Has an Ignition Problem
Gas furnaces rely on precise electronic sequencing. When you call for heat, the draft inducer fan starts, pressure switches close, the ignitor glows cherry red, and gas valves open. If any safety or ignition component fails, the furnace will shut down.
Clicks Repeatedly Without Lighting
Hearing clicking relays followed by silence indicates the control board is calling for heat, but the broken ignitor fails. Call for fast emergency dispatch.
Blower Blows Cold Air in Winter
If the indoor blower fan runs constantly but only blows chilled air, the burners failed to light, leaving the heat exchanger cold.
Burners Light Then Shut Off in 3s
When burners extinguish after 3 seconds, the flame sensor is oxidized. We test sensor current and verify signals from the digital thermostat.
Control Board Flashing LED Code
Furnace diagnostic LED lights blink specific error codes (3 blinks for ignition lockout, 4 for high-limit open). We test safety circuits and airflow across ductwork plenums.
Pilot Light Won't Stay Lit
On older standing pilot furnaces, a pilot flame that goes out the moment you release the knob indicates a worn thermocouple, easily checked during a seasonal tune-up.
Loud "Boom" or Delayed Ignition
A loud bang when the furnace ignites is caused by gas pooling inside the chamber before ignition, risking dangerous fractures in the furnace heat exchanger.
Our 4-Step Furnace Ignition Repair Protocol
We do not just swap parts blindly. We test resistance, voltage feeds, and safety circuits to ensure reliable ignition all winter long, optimizing performance alongside our whole-home air duct inspection.
Multimeter Resistance Test
We disconnect the ignitor harness and measure ohms resistance (normal range 30–90 ohms for silicon carbide, 11–20 ohms for silicon nitride) to confirm circuit breaks.
Flame Sensor Microamp Test
Using an in-line microamp meter, we test flame rectification current (minimum 1.5 to 4.0 µA DC). We precision-clean oxidized sensor rods with emery cloth.
Heavy-Duty Nitride Upgrade
We replace fragile factory silicon carbide ignitors with military-grade silicon nitride ignitors that resist thermal shock and last 2 to 3 times longer.
Gas Valve & Burner Fire Test
We cycle the furnace through 3 start-ups, verify gas manifold pressure (3.5" W.C. natural gas), inspect the blower motor relay, and confirm smooth cross-ignition.
Fast Winter Heating Dispatch Across Plano, TX
When a North Texas blue norther sweeps through Collin County dropping temperatures below freezing, your furnace needs to light reliably on the first attempt. Keep your heating equipment in prime condition with an annual seasonal tune-up or emergency heating visit:
- Willow Bend North & Country Club (75093)
- Legacy West & Ten Mile Creek (75024)
- Deerfield & Prairie Creek (75024)
- Spring Creek Parkway Corridor (75023)
- Haggard & Old Plano Heritage (75074)
- Park Boulevard & Los Rios (75074)
Frequently Asked Questions: Furnace Ignition in Plano
Never touch the dark ceramic or nitride heating element of a furnace ignitor with bare fingers. Natural oils from human skin create hot spots on the element during heating cycles that will cause the ignitor to crack and burn out prematurely within days.
Standard factory silicon carbide ignitors generally last 4 to 6 years. The premium silicon nitride upgrades installed by our technicians are far more durable and typically last 8 to 12+ years under normal usage and regular annual tune-ups.
Yes. Delayed ignition indicates raw natural gas is collecting inside the heat exchanger before ignition sparks. The resulting shockwave can crack the heat exchanger cells and blow out furnace access panels. Turn off the gas switch and request professional repair immediately.