How to Change Speed on a Tempstar Furnace Model NUG5100BFA1 Blower Motor

Julie Boleware

Proper air flow is necessary for an air-conditioning/heating system to function correctly. There are several reasons a person would want to change the speed on a blower motor. For example, increasing the air speed increases the capacity of the system, meaning a 3-ton system can become a 3 1/2-ton system. Decreasing the air speed can increase the dehumidifying capabilities, which makes the air more comfortable. The Tempstar furnace model NUG5100BFA1 blower motor is an older model, but it is still a highly capable gas furnace.

  1. Switch the breaker to the air handler off.

  2. Determine what speed you want to change to. Black is high speed. Orange is medium high. Blue is medium. Red is low.

  3. Remove the nuts on the air handler access panel and open to top and bottom panels.

  4. Locate the furnace control board on the bottom half of the air handler, centered. Locate the terminal marked, "heat," on the control board.

  5. Slide off the speed tap wire attached to the heat terminal and replace it with the wire color that matches the desired speed.

  6. Put the removed speed tap wire on the tab that the replacement wire came from.

  7. Put the access panels back on the air handler and turn the power back on.