Lennox 10M78 Blower Motor
The Lennox 10M78 Blower Motor is a 1 HP programmed ECM (electronically commutated motor) for compatible Lennox HVAC equipment that uses a variable-speed blower. It is identified as Lennox catalog number 10M78 and manufacturer part number 104758-07. The motor runs on 120/240 VAC, single-phase, 50/60 Hz power and delivers variable-speed operation up to 1250 RPM. It is rated at 11.5/6.9 amps and has reversible rotation.
Unlike a standard PSC blower motor, an ECM is a brushless DC motor with its own built-in control electronics. The furnace or air handler control board sends it a speed or torque command, and the motor adjusts itself to hold the airflow the system calls for even as filters load and static pressure changes. That is why a programmed ECM such as the 10M78 is application-specific. Its internal programming is matched to the equipment's airflow profile, so horsepower and shaft size alone do not make one motor interchangeable with another. The 10M78 is listed for the Lennox CBX25UHV-060 model. The motor is a 48-frame design with ball bearings, belly-band mounting and a 1/2 inch x 4.5 inch shaft.
Before condemning an ECM, check the 120/240 VAC supply, the control signal from the board, the wiring harness and connectors, since a failed control board or loose plug can mimic a bad motor. Always inspect the blower wheel as well, because a dirty, bent or unbalanced wheel causes vibration that shortens bearing and motor life and can destroy the replacement. Common signs of a failing motor include no start, hunting or surging speed, bearing noise, overheating and an error code or lockout from the control. Confirm rotation direction, mounting position, shaft dimensions and electrical connections against the original before installing.
Key Benefits
- Correct Motor Class: 1 HP programmed ECM built for variable-speed Lennox blowers, Lennox 10M78 / 104758-07.
- Electrical Ratings: 120/240 VAC, single-phase, 50/60 Hz operation at 11.5/6.9 amps with speed up to 1250 RPM.
- Efficient Airflow: ECM technology adjusts output to the system's airflow demand, helping hold comfort and reduce energy use compared with a fixed-speed motor.
- Flexible Installation: reversible rotation and belly-band mounting let the motor match the rotation and mounting of the original installation.
Common Questions
- What type of motor is the Lennox 10M78? It is a 1 HP programmed ECM variable-speed blower motor, also listed under 104758-07.
- What voltage and speed does the 10M78 use? It runs on 120/240 VAC, single-phase power with variable speed up to 1250 RPM at 11.5/6.9 amps.
- Can I use the 10M78 in place of another Lennox blower motor? Only after checking the equipment model, serial number and original motor part number. Programmed ECM motors are application-specific, so horsepower and physical size alone do not confirm compatibility.
Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.