Part 12 Description - 2100 Series

When the heater senses a heat call, the variable speed blower is energized and circulates room air through the brick core. This heated air is discharged into the room to maintain the desired temperature. In an effort to keep the room temperature constant, the blower automatically adjusts to the appropriate speed and may continue to operate after the room temperature set point has been reached. If there is no heat in the brick core, the blower will only run in low speed. Once the air discharge sensor is satisfied that the discharge air temperature has reached 90°F or greater, the blower will begin to adjust its speed according to the heat required. Refer to Location 111 (L111)  for the current discharge air temperature.

Blower speed is determined by the amount of voltage sent to the blower from the base I/O relay board. As the fan speed requirements increase, voltage to the blower increases. Check voltage AC from the L2 terminal to the blower terminal on the base I/O relay board and compare this reading to the Blower/Damper Activation Chart. 

Early blower motors had sleeve type bearings that were permanently lubricated. Steffes does not recommend oiling these motors; however, if desired, a motor can be re-oiled with SAE 20 oil. Over oiling the motor can cause motor failure! Later blowers were equipped with ball bearings. These motors are not intended to be lubricated.

Vibration of the blower can be caused by a build up of dirt and debris. If there is a noise issue, clean the blower wheel and verify that the blower is mounted properly. All motor windings must have at least 20 meg ohms of resistance from each of the leads to ground. Resistance across the motor leads should as shown in the table below. This motor is less than 1/8 HP.