Tempstar Hot Surface Igniter for TNK125N20A1 — Silicon Nitride OEM | Ships Today

Overview

This is a genuine OEM hot surface igniter (part number 1009524, IGNITOR/SENSOR HSP SK) for the Tempstar TNK125N20A1 gas furnace. The hot surface igniter glows red-hot to light the gas burners on every call for heat. After thousands of heating cycles the element becomes brittle and eventually cracks or burns out, leaving the furnace running the inducer and gas valve but never igniting. A bad igniter is among the most common no-heat failures on Tempstar/Heil furnaces, and this exact-fit replacement restores fast, dependable ignition.

Specifications

Compatibility

Engineered for the Tempstar TNK125N20A1 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.