521138 Suburban Furnace Blower Motor 12V DC, NT-34 M S SP NT-40

Fits NT‑34, NT‑34M, NT‑34S, NT‑34SP, NT‑40 Furnaces MOTOR OLD #231381 MTR W/BRACKET

Replaces: 231381

The Suburban 521138 is the OEM‑spec 12‑volt blower/combustion motor used in the NT‑34 and NT‑40 furnace families. These are the highest‑output NT‑series furnaces, requiring a larger motor to deliver both combustion air and heated‑air circulation. When the original motor becomes noisy, slow to start, or fails to reach proper RPM, this replacement restores correct airflow and reliable ignition performance.

It matches the original Suburban mounting pattern, shaft length, rotation, and electrical characteristics for a direct, no‑modification installation.

Key Features

• OEM‑style Suburban NT‑34 / NT‑40 furnace motor

• Fits NT‑34, NT‑34M, NT‑34S, NT‑34SP, NT‑40

• Provides correct combustion‑air and circulation airflow

• Factory‑matched rotation, shaft length, and mounting footprint

• Built for high‑temperature RV furnace environments

• Restores proper ignition, heating output, and safety performance

When this motor typically needs replacement

• Blower slow to start or fails to reach ignition airflow

• Furnace locks out or cycles without lighting

• Motor overheats or trips thermal protection

• Grinding, squealing, or vibration during operation

• Weak airflow from registers despite clean ducts