F-40
What code F-40 means on a Kenmore tumble dryers, what causes it, and which part to check first.
● SEVERITY: HIGH
Kenmore F-40 means: Communication error between the main electronic control board and the blower motor control board. The documented cause is: Unplug the dryer and check the wire harness connections between the blower motor control board and the main electronic control board. Reconnect any loose wires or replace the wire harness if damaged.
What F-40 means
Communication error between the main electronic control board and the blower motor control board
The display shows F-40 and the machine stops until the fault is cleared.
What the technical documentation says
Causes documented in the technical source published by applianceaid.com
| DOCUMENTED CAUSE OR CHECK |
|---|
| Unplug the dryer and check the wire harness connections between the blower motor control board and the main electronic control board |
| Reconnect any loose wires or replace the wire harness if damaged |
| A blown thermal fuse will prevent the blower motor control board from getting power, triggering the F-40 code |
| Check the resistance of the thermal fuse |
| Replace the thermal fuse if you measure infinite resistance through the fuse |
| Check the wire harness connections between the blower motor and the blower motor control board |
| Reconnect any loose wires or replace the wire harness if damaged |
| Check to see if the blower fan spins freely |
| If not, check for a clog or restriction in the fan housing |
| Replace the blower fan if it's damaged |
| If the wire connections, thermal fuse and blower fan are okay, |
Replacement parts
Tools you'll need
Before you open anything
Unplug the machine before removing any panel. Lint is flammable: never run a dryer with the filter removed, and clear the duct if the code points to airflow.
What to check, in order
From the quickest check to the one that needs a technician.
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Frequently asked questions
What does F-40 mean on a Kenmore?
Communication error between the main electronic control board and the blower motor control board The documented cause is: Unplug the dryer and check the wire harness connections between the blower motor control board and the main electronic control board. Reconnect any loose wires or replace the wire harness if damaged. A blown thermal fuse will prevent the blower motor control board from getting power, triggering the F-40 code. Check the resistance of the thermal fuse. Replace the thermal fuse if you measure infinite resistance through the fuse. Check the wire harness connections between the blower motor and the blower motor control board. Reconnect any loose wires or replace the wire harness if damaged. Check to see if the blower fan spins freely. If not, check for a clog or restriction in the fan housing. Replace the blower fan if it's damaged. If the wire connections, thermal fuse and blower fan are okay,
Can I fix F-40 myself?
It depends on the part involved: Unplug the dryer and check the wire harness connections between the blower motor control board and the main electronic control board. Reconnect any loose wires or replace the wire harness if damaged. A blown thermal fuse will prevent the blower motor control board from getting power, triggering the F-40 code. Check the resistance of the thermal fuse. Replace the thermal fuse if you measure infinite resistance through the fuse. Check the wire harness connections between the blower motor and the blower motor control board. Reconnect any loose wires or replace the wire harness if damaged. Check to see if the blower fan spins freely. If not, check for a clog or restriction in the fan housing. Replace the blower fan if it's damaged. If the wire connections, thermal fuse and blower fan are okay, Clearing a filter or straightening a hose is within reach of anyone; anything behind a panel means mains electricity and water together — that is a job for a technician.
Does Kenmore use other codes on this appliance?
Yes: we document 65 other codes for Kenmore on this tumble dryers. They are listed at the bottom of this page, each with its own meaning.
Does the same code mean the same thing on other brands?
Often not. The same two characters can point to completely different faults depending on the manufacturer — always check the page for your own brand.