Ignition
OEM and universal replacement parts for all major HVAC brands. Same-day shipping on orders before 3 PM CST.
Understanding Furnace Ignition Systems
Modern furnaces use electronic ignition to light the gas burners — no standing pilot light. When the ignition system fails, your furnace won't produce heat at all. The good news: ignition parts are affordable ($15-$50) and most are a straightforward DIY replacement.
Types of Ignition Components
Hot Surface Igniters (HSI) are the most common ignition source in furnaces made after 1990. The silicon carbide or silicon nitride element glows red-hot (1,800°F+) to ignite the gas. They're fragile — never touch the element with bare hands, as skin oils cause hot spots that crack the igniter. Silicon nitride igniters (like the Goodman 0130F00008) last longer than silicon carbide but cost more.
Spark Ignition Electrodes produce a spark to light the gas, similar to a gas grill igniter. Common in Lennox, Trane, and some commercial units. They wear down over time as the electrode tip erodes. If your furnace clicks but won't light, the electrode gap may be too wide.
Ignition Control Modules manage the entire ignition sequence — they tell the inducer motor to start, the igniter to glow, the gas valve to open, and verify flame. When the module fails, you'll see error codes on the board. Honeywell S8610U and S8670 are common universal replacements.
Hot Surface Igniter: Repair vs Replace
Igniters cannot be repaired — they're a replace-only part. The typical lifespan is 3-7 years depending on cycling frequency. If your furnace lights then shuts off within 3-7 seconds, the issue is usually the flame sensor, not the igniter. If it doesn't glow at all, the igniter or the control board has failed.
Finding Your Replacement
Igniters come in different shapes, mounting styles, and wiring lengths. The safest way to order is by equipment model number — enter yours above. If you have the old igniter in hand, match the shape (flat, round, or fork-style) and measure the lead wire length.
Frequently Asked Questions
How long do hot surface igniters last?
Silicon carbide igniters typically last 3-5 years. Silicon nitride igniters (like Goodman 0130F00008 or Carrier LH33ZS004) last 7-10+ years. If your furnace is cycling more than usual or occasionally fails to light on the first try, the igniter is weakening and should be replaced preventively before it fails completely on a cold night.
My furnace clicks but won't light — igniter or flame sensor?
If you hear the inducer start, then hear clicking but see no glow from the igniter, the igniter has failed. If the igniter glows red and the gas lights but the flame goes out after 3-7 seconds, the flame sensor is the problem, not the igniter. The flame sensor is a $15 part and should be checked first.
Can I touch a hot surface igniter with my bare hands?
No — never touch the ceramic element with bare hands. Skin oils create hot spots that cause the igniter to crack when it heats up. Handle it by the base or mounting bracket only. If you accidentally touch it, clean the element with rubbing alcohol and a lint-free cloth before installing.
What's the difference between silicon carbide and silicon nitride igniters?
Silicon carbide (gray/dark) is the older, cheaper type — more brittle and shorter lifespan. Silicon nitride (white/light) is the newer type — more durable, resists cracking, and lasts 2-3x longer. Silicon nitride costs $10-15 more but is worth the upgrade. Most new furnaces ship with silicon nitride from the factory.
How do I test if my igniter is bad?
Visual test: turn on the furnace and watch through the burner viewport — the igniter should glow bright orange within 15-30 seconds. Multimeter test: measure resistance across the igniter terminals. A good silicon carbide igniter reads 40-90 ohms. A good silicon nitride reads 10-20 ohms. Open circuit (infinite resistance) means the element is cracked and must be replaced.