Troubleshooting Your Furnace

Posted on: 5 November 2018

If your mobile home's furnace has stopped blowing out hot air when you turn on the thermostat, then it's very likely the blower motor has failed. Typically, before the blower motor stops working, it will make gravely or squealing noises when the furnace is running. If you have been hearing them, then this is almost guaranteed to be the problem.

The squealing and gravely noises come from the bearings inside of the blower motor itself. As the bearings start to dry out and fail from age, they will make increasingly more and more noise until the day they completely stop turning. 

When the bearings fail, the motor will burn out, and you may smell some smoke coming from your registers.

Thankfully, the forced-air furnaces installed in mobile homes are easy to work on, and replacement parts are readily available online.

While it is always advisable to have a licensed HVAC technician install replacement parts in your furnace, if you choose to tackle your furnace repairs yourself, below are the necessary steps to do so:

Step 1: Purchase a Complete Blower Motor Assembly Replacement Online

Rather than trying to replace just the blower motor itself, you should replace the entire assembly.

A blower motor assembly includes each of these important parts:

• a blower motor
• a squirrel cage and wheel
• a capacitor
• a metal housing

In addition, most replacement units will come with a short electrical cable with a plug adapter for use on older-style furnaces.

Step 2: Turn Off the Breaker for the Furnace

To prevent electrocution, you must turn off the electrical power to the furnace at the panel. Flip the breaker to the "off" position, and then test the system with a voltmeter to ensure the power is completely off before you attempt to work on it.

Step 3: Disconnect and Remove the Old Blower Motor Assembly

To remove the failed blower motor assembly, unscrew each of the four screws on its base holding it in place. 

The electrical connection for the assembly is a ribbon cable with a plastic connector. Disconnect this connector.

Remove the assembly from the furnace for recycling or disposal.

Step 4: Install the Replacement Blower Motor Assembly

Place the new blower motor assembly in place and attach it using the screws you previously removed.

Attach the power cable. If the ends don't match, then you will need to use the adapter cable.

Step 5: Restore the Power and Test the Furnace

Finally, turn the power back on to the furnace and test it to make sure the new blower motor is working as expected.