Furnace Ignitor Types — Silicon Carbide vs Silicon Nitride
Published: July 23, 2026 — BC Wide Home Services Ltd, doing business as BC Wide Heating & Air Conditioning — Greater Vancouver, BC
Silicon Carbide Ignitors
Standard ignitor type on most furnaces. Cost: $20-40 for the part. Lifespan: 3-5 years. Appearance: dark grey, flat rectangular element. Characteristics: glows bright orange, fragile (cracks easily from thermal stress), slower to reach temperature. Most common and widely available.
Silicon Nitride Ignitors
Premium ignitor type on higher-end furnaces. Cost: $40-80 for the part. Lifespan: 5-10 years. Appearance: shiny black, more robust construction. Characteristics: more durable (resists thermal shock), reaches temperature faster, longer lifespan. Found on Carrier, Lennox, and Trane premium models.
Which to Choose
When replacing an ignitor, use the same type specified by the manufacturer. Upgrading from silicon carbide to silicon nitride may require additional modifications and is not recommended without manufacturer approval. For most furnaces, silicon carbide ignitors are reliable and affordable — keep a spare on hand for winter emergencies.