Downdraft Ventilation System: Fan not pulling much air

When the downdraft vent fan isn’t pulling much air, clogged grease filters, air duct problems, a fan motor failure or a broken blower wheel could be causing poor air suction.

First, check the condition of the grease filters and wash or replace them if dirty.

Next, check the air damper on the vent duct cap attached to the outside of your house. That air damper keeps outside air from flowing into your home when the downdraft vent fan isn’t running. Repair or replace the air damper if it doesn’t open to allow downdraft exhaust air to flow out of the exhaust duct.

Check the blower wheel for damage because a damaged blower wheel won’t move air through the downdraft vent properly. Replace the blower wheel if damaged.

A weak fan motor won’t turn the blower wheel at the right speed to move air through the downdraft vent. If the fan motor makes noise or doesn’t turn the blower wheel at full speed when activated, replace the fan motor.

downdraft ventilation system

These repairs may help solve your downdraft ventilation system problem

Clean the downdraft grease filters

Clean the downdraft grease filters

Clogged grease filters diminish airflow through the downdraft vent. Wash the aluminum grease filters in a mild detergent or in the dishwasher. Allow the grease filters to dry completely and then reinstall them in the downdraft vent.

Replace the downdraft vent grease filters

Replace the downdraft vent grease filters

If the aluminum grease filters are damaged or missing, replace them.

Replace the downdraft blower fan motor

Replace the downdraft blower fan motor

If the blower fan motor doesn't run when the vent pops up, check the limit switches and the fan control switch. If the switches are okay, replace the blower motor.

November 1, 2015
By Lyle Weischwill
How to replace a downdraft vent blower motor

A downdraft vent blower motor that won't start could have a worn-out motor. This DIY repair guide and video show how to replace a downdraft vent blower motor in less than 30 minutes.

Repair difficulty
Time required
 30 minutes or less
Read more
Replace the downdraft blower wheel

Replace the downdraft blower wheel

If the blower motor has excessive vibration and noises when running, check for loose mounting nuts and fan bracket securing the blower motor. If the fan bracket and mounting nuts are tight, the blower wheel is likely unbalanced, replace the blower wheel.

Symptoms common to all downdraft ventilation systems

Choose a symptom to see related downdraft vent repairs.

Main causes: lack of electrical power, up/down activation switch failure, bad vent gear motor
Main causes: fan control switch failure, bad blower fan motor, broken blower wheel, wiring failure
Main causes: electrical power failure, up/down activation switch problems, vent gear motor failure
Main causes: problems with the vent limit switches, up/down activation switch failure
Main causes: clogged grease filters, air duct problems, fan motor failure, broken blower wheel

Repair guides common to all downdraft ventilation systems

These step-by-step repair guides will help you safely fix what’s broken on your downdraft vent.

How to replace a downdraft vent up/down button pad

The up/down button pad located on top of the air vent engages the activating switch when pushed to raise the air vent. Replace the up/down button pad if damaged.

Repair difficulty
Time required
 15 minutes or less
November 1, 2015
By Lyle Weischwill
How to replace a downdraft vent gear motor

The gear motor raises and lowers the air vent when you push the activating switch. Replace the gear motor if defective.

Repair difficulty
Time required
 15 minutes or less
November 1, 2015
By Lyle Weischwill
How to replace a downdraft vent blower motor

The blower motor spins the fan blade that removes smoke and steam from the cooktop area. Replace the blower motor if it doesn't run when activated.

Repair difficulty
Time required
 30 minutes or less

Articles and videos common to all downdraft ventilation systems

Use the advice and tips in these articles to get the most out of your downdraft vent.

April 17, 2019

Downdraft vent common questions

By Sears PartsDirect staff

The most commonly asked questions about downdraft vents are answered by our experts.

January 18, 2016

How to use a multimeter to test electrical parts video

By Sears PartsDirect staff

Learn how to use a multimeter to check for wiring problems in an appliance that's not working

December 2, 2015

Wiring schematic symbols explained video

By Sears PartsDirect staff

Learn some of the most common symbols found in a wiring diagram and what they mean.