When the heater senses a heat call, the 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 high speed if the room temperature drops 5 degrees below set point (Location 16).
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 megohms of resistance from each of the leads to ground. Resistance across the motor leads should be as shown in the table below.
|
Type |
120V |
240V |
|---|---|---|
|
Fasco |
15-19 |
60-75 |
|
PTech Multi-Tap |
40-55 |
160-210 |