How to Troubleshoot a Convection Blower

A convection blower is a fan that circulates warm air into the room. This part is used to circulate air through the stove and into your room. In some models, it protects the electrical parts from overheating. Convection blowers are offered as an optional accessory for wood and gas stoves and fireplaces to help improve heat distribution. These blowers come in many different sizes and shapes to accomplish this task.

There are the 3 common ways that convection blowers fail: the blower fails to turn on, the blower fails to turn off, or the blower makes noise. Asking the following questions will help determine the source and how to resolve the issue.

Remember to always unplug the stove from power before testing or cleaning any components.

Problem #1 - The convection blower does not turn on:

There are several components that could prevent the convection blower from running. Refer to the wiring diagram from your owner’s manual as a map to follow the circuit that powers the convection blower. Start from the blower and work backward to the power source to determine where the breakdown occurs.

Is there an obstruction within the blower housing?

Check for any possible obstruction that would prevent the impeller from turning. Use a soft paintbrush and/or canned air to gently clear creosote or debris trapped within the convection blower housing or clogging the fan blade.

Is power reaching the convection blower?

Convection blowers operate on standard wall voltage and should receive between 115-120 volts. Check the wire connections to the convection blower with a multimeter to measure for voltage.

Power is present – Replace the convection blower.

No power is present – Refer to the wiring diagram in the owner’s manual to determine any sensors or safety switches that might be interrupting the flow of electricity to the convection blower.

Does the convection blower have a heat-activated sensor?

Many convection blowers include a heat-activated thermodisc that detects a minimum temperature before engaging the convection blower. This prevents the fan from blowing cold air into your living space. A defect in this snap switch could prevent the convection blower from running. You may need a heat source such as a hairdryer or small butane torch to activate the switch when you test it.

Click HERE for detailed instructions on testing the snap disc.

Does the convection blower operate when bench tested?

Testing a part outside the stove is known as a bench test. This isolates the blower to test its performance independently from the rest of the stove. To Bench Test a Convection Blower:

1. Unplug the stove and the convection blower (if applicable) from power.
2. Uninstall the blower from the stove and connect a test wire (like this one HERE) to the corresponding posts or wires on the motor.
3. Plug the test wire into a power strip with the power switched off, then plug the power strip into the wall.
4. Stabilize the convection blower and turn the surge protector on. The fan should spin with low noise and vibration.

Problem #2 - The convection blower does not turn off:

This issue most commonly results from a defect in either the control board, the thermostat, or the stove wiring.

Is the blower controlled by a temperature sensor?

The sensor that controls the convection blower could be stuck closed, allowing the convection blower to keep running.  Try removing one of the connections from the blower snap disc to open the circuit and allow the blower to turn off. If the blower is able to shut off the temperature sensor needs to be replaced.

Click HERE for detailed instructions on testing the snap disc.

Is the stove operating on a thermostat?

A faulty thermostat could prevent the blower from turning off if it reads the room temperature inaccurately. Operate the stove in manual mode or bypass the thermostat on the stove to test for a defective thermostat.

Inspect stove wiring for a short or a blown fuse?

Follow the wiring of each component to make sure everything is securely connected and there are no cracked or fraying wires. An exposed wire can cause the blower or the stove to ground out. If the fuse continues to blow there may be a problem with the blower sending too much power back to the control board.

If the wiring checks out, there could be a defect in the circuit board. Consult a local technician to confirm that the control board is the source of the problem. Sometimes the board may be rebuilt, otherwise, it will need to be replaced.

Learn more about our rebuild service HERE.

Problem #3 - The convection blower makes noise:

A high-pitched “screeching” sound often indicates that the bearing is wearing out. Typically, this will require replacing the motor since most convection blowers have sealed bearings that cannot be oiled.

A new blower motor may sound noticeably louder than your previous part. Generally, noise levels at or below 70 decibels are considered normal for a new blower. Give the new blower a week or so to settle in to see if the noise level adjusts. You can also ask these 4 questions to determine the source of excessive blower noise:

1) Was the gasket also replaced when the new part was installed?

Some convection blowers use a gasket to absorb vibration and reduce noise. We recommend replacing this gasket any time the blower is replaced or removed for annual deep cleaning.

2) Were the mounting bolts evenly tightened?

Uneven installation causes the blower to wobble and could create a louder than usual blower sound.

3) Is there a loose set screw or warped impeller?

Sometimes the set screw that holds the impeller against the motor shaft can loosen during shipping. Inspect the set screw and tighten if necessary. An impeller contacting the housing may be remedied by bending the housing until it is no longer touching the blades, but usually requires replacement. Continued operation of the blower with an out-of-balance impeller could cause pre-mature failure of your motor.

4) Can the noise be replicated by bench testing the convection blower outside of the stove?

Testing a part outside the stove is known as a bench test. This isolates the blower to test its performance independently from the rest of the stove.

To Bench Test a Convection Blower:

1. Unplug the stove and the convection blower (if applicable) from power.
2. Uninstall the blower from the stove and connect a test wire (like this one HERE) to the corresponding posts or wires on the motor.
3. Plug the test wire into a power strip with the power switch in the off position, then plug the power strip into the wall.
4. Stand clear of the convection blower and switch the surge protector on. The fan should spin with low noise and vibration.

If the blower still makes the same noise outside of the stove then it may qualify for a warranty replacement. Reach out to our customer service team by phone: 406-272-9850, e-mail: support@stove-parts-unlimited.com, or chat online HERE to determine if your blower qualifies for a replacement.

Still experiencing trouble? We are here to help. Contact our customer service team by phone: 406-272-9850, e-mail: support@stove-parts-unlimited.com, or chat online HERE.