# How to Fix Kenmore Error F70 (No Communication)
The F70 error is a critical fault that generally prevents the machine from starting or continuing a cycle. While this is technically a washing machine error, the communication failure often involves components that manage specific high-load functions, such as the machine’s internal drying unit (if applicable).
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## What Does Kenmore Error F70 Mean? (Explanation)
The F70 error code means the washing machine’s main computer, typically called the Central Control Unit (CCU), has lost communication with one of its key secondary control boards.
In simpler terms: **The main “brain” of the washer is not receiving the data signal it expects from a critical component board, leading to a system shutdown.**
Based on the machine’s design, the failure often originates from the control board responsible for handling complex functions, which in many Kenmore models is the **Dryer Control Board** (also known as the Heater Control Board or ACU/MCU depending on the model). This loss of communication is frequently caused by power surge damage or simple component burnout on the secondary board itself.
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## Step-by-Step Fix: Diagnosing and Repairing Error F70
Before performing any physical inspection, **always unplug the washing machine from the wall power outlet.**
### Step 1: Perform a Hard Reset
Communication errors can sometimes be caused by temporary software glitches.
1. **Unplug** the washer completely from the electrical outlet.
2. Wait a minimum of **5 minutes** to allow any residual voltage to dissipate from the capacitors and internal memory.
3. **Plug** the machine back in.
4. Attempt to run a short diagnostic or wash cycle.
If the F70 error persists, the issue is hardware-related and requires internal inspection.
### Step 2: Inspect the Wiring Harnesses
A loose or damaged wire connection between the CCU and the Dryer Control Board will instantly cause the communication failure.
1. **Locate the Control Boards:** Depending on your model, the main CCU is usually located near the top back of the machine, and the Dryer Control Board is often located elsewhere, sometimes near the heating element or motor.
2. **Trace the Main Harness:** Find the large ribbon cable or wiring harness connecting the CCU to the secondary board (the Dryer Control Board).
3. **Check for Damage:** Look for pinched, cut, or chewed wires.
4. **Secure Connections:** Firmly disconnect and then reconnect the harnesses at both ends (CCU and Dryer Control Board) to ensure a proper seating, looking for corrosion or burnt plastic on the connectors.
### Step 3: Visually Inspect the Dryer Control Board (The Likely Culprit)
Because the Dryer Control Board is the most frequent point of failure for an F70 communication code, a visual inspection is vital.
1. **Remove the Board:** Carefully remove the housing or screws securing the Dryer Control Board (refer to your specific machine’s tech sheet for location).
2. **Look for Physical Damage:** Examine the surface of the circuit board for obvious signs of failure:
* Burn marks, scorch marks, or brown discoloration.
* Bulging or leaking capacitors (small cylindrical components).
* A strong, acrid electrical smell.
3. **Inspect the Microchip:** Focus on the main communication chip. If it appears cracked or melted, the board is definitely compromised.
If you find any of these visual signs of damage, the board has failed and must be replaced.
### Step 4: Test Voltage (Advanced)
If the board looks visually perfect, you will need a multimeter to confirm it is receiving the correct voltage from the main power supply.
1. **Safety First:** This step requires the machine to be plugged in and possibly disassembled. **Only attempt this if you are comfortable working with live electricity.**
2. **Identify Power Pins:** Locate the main power input pins on the Dryer Control Board connector (often labeled L1 and Neutral, or specific voltage inputs like 12V or 5V DC).
3. **Measure Power:** With the washer plugged in and the multimeter set to the correct AC or DC voltage range, test the incoming voltage at the board connector.
* If the board is receiving the correct voltage but the error persists, the board has failed internally and cannot send a signal back to the CCU.
* If the board is **not** receiving voltage, the fault lies further back in the wiring harness or the main CCU has failed. (This is less common for F70.)
### Step 5: Replace the Dryer Control Board
If the hard reset and wiring checks failed, and especially if you saw visual damage, replacing the Dryer Control Board is the necessary final step to restore communication.
Once the new board is installed and connected securely, plug the machine back in. The F70 error should clear immediately upon powering on, allowing you to select and run a new wash cycle.
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Check the price for a replacement Dryer Control Board here: https://www.amazon.com/s?k=Kenmore+Dryer Control Board&tag=trivian-20
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