Gas Furnace Motor Installation - Come See Step By Step Guidelines For Installing A Motor
We will be discussing changing a direct drive blower motor and capacitor on a traditional up flow gas furnace as would be found in a basement of a home as these types of furnaces are by far the most common. Changing motors in horizontal units in an attic or a crawl space are very similar but will vary with the equipment. If you are not comfortable with working on 120 volt equipment please consult a professional Heating and Air Conditioning company to do this work.
Before we begin, we go shut off the main 120 volt power to the furnace. This may be able to be accomplished by turning off the switch at the furnace where the main power comes into the furnace. Sometimes this switch is mounted on the floor joists above the furnace, or on the side of the furnace itself. In the interest of safety, we also shut the breaker off at the main house panel. We use of a volt meter to be sure the power is really off.
The next step is to remove the screws or bolts that hold the blower assembly up inside the furnace. Some blowers are on a sliding track while others are simply held in by these bolts or screws so it is a good idea to use a small 2"x4" piece of lumber to lower the blower out of the furnace as the holding screws are removed. If there is a control board attached to the blower assembly all wires should be labeled so that if any wire is knocked off it can be re installed on the correct terminals that it came from. Hopefully the blower assembly will come down with all the wires in place. If there is a control board mounted on the blower we will have to remove it with the wires all attached and tie it up out of harms way. The same is true of any other component mounted on the assembly.