Whirlpool Dryer Error Code F70/F71 — Communication Failure Between Control Boards
What this means
The F70 and F71 error codes on Whirlpool dryers indicate a communication failure between the main electronic control board (ECB) and the user interface control board (UICB). These boards communicate via a serial data line, and when that link is broken, the dryer displays F70 or F71. Common causes include a loose or damaged ribbon cable, a failed solder joint on either board, or a complete board failure. This error is particularly common on Whirlpool Duet dryers.
Alternate codes: F71
Step-by-step fix
4 stepsPower cycle the dryer
Unplug the dryer for 5 minutes. This can resolve temporary communication glitches between the boards.
Power surges and static discharge are common causes of temporary F70/F71 errors.
Check the ribbon cable
Unplug the dryer. Remove the top panel and control console. Locate the ribbon cable or wire harness connecting the two boards. Disconnect it from both ends, inspect for damage, and re-seat firmly.
Look for oxidation on the connector pins — clean with a pencil eraser or contact cleaner if present.
Inspect both control boards
Examine both the main control board and the user interface board for burned components, cracked solder joints, or visible damage.
The serial communication chips on these boards are particularly susceptible to power surge damage.
Replace the faulty board
If the ribbon cable is good, one of the boards has failed. Replace the user interface board first (it's less expensive). If the error persists, replace the main control board.
Some technicians recommend replacing both boards together if they are relatively inexpensive for your model.
When to call a professional
Determining which of the two boards has failed can require diagnostic equipment. A professional can quickly identify the faulty board.
Related error codes
Information compiled from manufacturer service manuals, official troubleshooting documentation, and appliance repair industry resources. This guide is for informational purposes only — always consult a qualified technician for complex repairs.
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