Tempstar 1/2 HP Variable Speed Blower Motor Kit for T8MPT050B12B1 — OEM ECM Motor | Ships Today

Overview

This OEM 1/2 HP variable-speed blower motor kit (part numbers 1173044 / 1175639) is the factory air-mover for the Tempstar T8MPT050B12B1 gas furnace. It is an ECM (electronically commutated motor) that ramps speed up and down to deliver quiet, efficient, constant-airflow operation across heating, cooling, and continuous-fan modes — a major comfort upgrade over fixed-speed PSC blowers. The kit includes the motor and module needed for a complete blower replacement. A failing variable-speed blower shows up as weak or no airflow, the blower hunting or surging, loud module relay clicking, or the furnace tripping on a high-limit because heat isn't being carried away. Replace the motor when the bearings are worn, the windings are open, or the ECM module has failed.

Specifications

Compatibility

Built for the Tempstar T8MPT050B12B1 furnace and the shared ICP / Heil / Comfortmaker variable-speed blower platform. Both 1173044 and 1175639 are valid OEM kit numbers for this application — verify your model and serial on the rating plate before ordering.

Installation Guide

1. Safety First — Disconnect power at the furnace switch and breaker and verify zero voltage with a multimeter; the ECM module can hold a charge, so wait several minutes before handling.
2. Access — Remove the blower compartment service panel and slide out the blower assembly.
3. Document — Photograph the motor wiring, module plugs, and blower-wheel position before disconnecting.
4. Remove — Unplug the 5-pin and power connectors, loosen the wheel set screw, remove the motor mount bolts, and separate the old motor from the housing.
5. Install — Fit the new motor to the blower wheel and housing, set the wheel spacing, torque the set screw, and reconnect all plugs per your photo.
6. Test — Restore power, run heat, cool, and continuous-fan modes, and confirm the blower ramps smoothly to full airflow without surging.

Signs You Need a Replacement

• Weak, no, or surging airflow from the supply registers
• Blower hunts, ramps erratically, or won't reach full speed
• Loud module relay clicking or a humming motor that won't start
• Furnace trips on high-limit from poor air movement

Shipping & Returns

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