# How to Fix Kenmore Error F70 (Heartbeat Error)
The F70 error code on a Kenmore washing machine indicates a critical communication failure, which is typically a straightforward but major issue to resolve.
—
## Explanation: What the F70 Code Means
The Kenmore F70 error code is often referred to as a **”Heartbeat Error.”**
In simple terms, this means the Central Control Unit (CCU)—the main computer board of your washer—is not communicating or receiving a signal from the User Interface (UI) board (the control panel you interact with). The F70 code is triggered when the machine’s primary components lose their electronic connection, meaning the critical “heartbeat” necessary for operation has stopped.
**The likely culprit for the F70 error is a failed Main Control Board.** Power surges, electrical shorts, or simple age can cause the electronic components on this board to fail, halting communication entirely.
—
## Step-by-Step Fix: How to Diagnose and Resolve F70
Before ordering a replacement board, it is crucial to rule out simpler electrical or connection issues. **Always unplug the washing machine from the wall before accessing internal components.**
### Step 1: Perform a Hard Reset (The Easiest Fix)
A temporary glitch can sometimes trigger the F70 error. A hard reset may clear the memory and restore communication.
1. **Unplug** the washing machine from the electrical outlet.
2. **Wait** 5 to 10 minutes (this allows residual charge to drain from the capacitors).
3. **Plug** the washer back in.
4. **Test** the machine by selecting a short cycle.
If the F70 code immediately reappears, proceed to the next step.
### Step 2: Check the Power Source
Ensure the electrical supply is stable and that the circuit breaker has not been tripped.
* Test the outlet using a small appliance (like a hair dryer) to confirm it is receiving power.
* Avoid using extension cords, as they can sometimes fail to provide the consistent voltage required by modern washing machines.
### Step 3: Inspect Wire Harnesses and Connectors
The main communication wires run between the UI panel (where the buttons are) and the CCU (the main board). These harnesses can become loose, corroded, or chewed by pests.
1. **Unplug the Washer.**
2. **Access the Control Boards:** Depending on your model, you may need to remove the top panel of the washer to expose the control board location.
3. **Trace the Connections:** Carefully follow the main ribbon cable or wire harness that runs from the User Interface board down to the Central Control Board.
4. **Look for Damage:** Inspect the connectors for signs of corrosion, burned plastic, or wires that have been pulled loose. If you find a loose connection, firmly re-seat it.
### Step 4: Visual Inspection of the Main Control Board (CCU)
If all external connections appear sound, the Main Control Board itself is the most likely source of the failure.
1. **Locate the Main Control Board (CCU).** (This is usually a large, green circuit board mounted within the casing.)
2. **Examine the Board:** Look closely for physical evidence of failure:
* **Burned Spots:** Blackened or scorched areas on the board.
* **Puffing:** Capacitors (small, cylindrical components) that look swollen or “puffed” at the top.
* **Odor:** A noticeable burnt electronic smell.
If you find visual damage, the diagnosis is complete: **The Main Control Board must be replaced.** If you find no visual damage, but steps 1 through 3 have failed, the board still requires replacement, as the internal components have likely failed electronically.
—
Check the price for a replacement Main Control Board here: https://www.amazon.com/s?k=Kenmore+Main Control Board&tag=trivian-20