Tempstar Hot Surface Igniter for TNK125N20B1 — Silicon Nitride OEM | Ships Today

Overview

This is a genuine OEM hot surface igniter (part number 1009524, IGNITOR/SENSOR HSP SK) for the Tempstar TNK125N20B1 gas furnace. The hot surface igniter is the component that glows red-hot to ignite the gas burners on each call for heat. Over thousands of heating cycles the igniter element becomes brittle and eventually cracks or burns out, leaving you with a furnace that runs the inducer and gas valve but never lights. A failing igniter is one of the most common no-heat causes on Tempstar/Heil furnaces. Replacing it with this exact-fit part restores reliable, fast ignition.

Specifications

Compatibility

Engineered for the Tempstar TNK125N20B1 gas furnace and shared Heil/ICP/Comfortmaker chassis using the same ignition assembly. Always confirm your unit's parts list before ordering.

Installation Guide

1. Safety First — Disconnect power at the furnace switch and verify zero voltage with a multimeter. Shut off the gas supply.
2. Access — Remove the furnace burner/service panel.
3. Document — Photograph the igniter bracket and wire routing before disconnecting.
4. Remove — Unplug the igniter connector, remove the mounting screw, and carefully withdraw the old igniter without touching the element.
5. Install — Mount the new igniter, handling it only by the ceramic base, and reconnect the harness per your photo.
6. Test — Restore gas and power, then run a heat cycle and confirm the igniter glows and the burners light.

Signs You Need a Replacement

• Furnace runs the inducer but never ignites (no-heat call).
• Visibly cracked, chipped, or no longer glowing igniter element.
• Repeated lockouts after several ignition attempts.
• Delayed ignition with a small rumble or roll-out.

Shipping & Returns

Ships same day before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.