ICP Hot Surface Igniter for X8MPT125J20A1 Two-Stage Furnace — OEM HSI | Ships Today

Overview

The hot surface igniter (OEM #1172533) is the heart of the ignition system on your ICP / Tempstar / Heil X8MPT125J20A1 two-stage gas furnace. When the thermostat calls for heat, the control board energizes this igniter; it glows red-hot (roughly 1,800–2,500°F) and ignites the gas as it flows from the valve. This is the single most common furnace failure point — the silicon-carbide or silicon-nitride element is brittle and degrades with every heating cycle. Typical failure symptoms include a furnace that clicks and tries to start but never lights, no glow visible through the inspection port, repeated lockouts with the LED flashing an ignition-failure code, or cold air blowing because the burners never fire. This OEM HSI is a direct-fit replacement rated for 120V operation and matched to the X8MPT ignition sequence.

Specifications

Compatibility

Engineered for the ICP-family X8MPT125J20A1 two-stage variable-speed gas furnace and shared across the Tempstar, Heil, Comfortmaker, and Day & Night badge-engineered equivalents that use the same burner assembly. Always confirm the part number on your existing igniter and the model/serial tag inside the furnace blower compartment before ordering.

Installation Guide

1. Safety First — Shut off the gas at the supply valve and disconnect electrical power at the breaker. Verify zero voltage with a multimeter at the furnace control.
2. Access — Remove the lower burner-compartment service panel.
3. Document — Photograph the igniter bracket position and the two-wire ignition harness before disconnecting.
4. Remove — Unplug the igniter connector, remove the mounting screw, and carefully withdraw the old igniter without touching the element. Note the exact insertion depth and angle relative to the burner.
5. Install — Handle the new igniter only by its ceramic base (skin oils crack the element), seat it at the same depth/angle, secure the screw, and reconnect the harness per your photo.
6. Test — Restore gas and power, initiate a heat call, and watch a full cycle to confirm the igniter glows, the burners light, and the flame sensor proves flame without lockout.

Signs You Need a Replacement

• Furnace attempts ignition (you hear the inducer and gas valve click) but never lights.
• No orange glow visible through the burner sight port during a heat call.
• Visible cracks, blisters, or white spots on the igniter element.
• Repeated ignition-failure lockouts after three retries with the control LED flashing a fault code.

Shipping & Returns

Ships same day on orders placed before 3 PM CST. 30-day returns on unused parts. Backed by the National HVAC Parts fitment guarantee — if it doesn't fit your X8MPT125J20A1, we make it right.