mypros+
Error code reference

Dacor Dishwasher Error Code F-8

Communication failure

Dacor codesDacor dishwasher codes

Communication failure – error in data transfer between the control board (master micro) and the power board (slave 1 micro), most commonly caused by a wet connector on the 4-wire low voltage connector (Ground, 5 VDC power, Data, Neutral).

First step from the service manual

Check the 4-wire low voltage connector between the control board in the door and the relay board in the base for moisture (most common cause).

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

MyPros+ Max

Get the full diagnostic procedure for F-8.

  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
Get the full procedure

$29/month · Cancel anytime · Or $9.95 3-day pass

What F-8 means on a Dacor dishwasher

The F-8 error code on a Dacor dishwasher indicates a communication failure between two microcontrollers: the master micro on the main control board located in the door, and the slave 1 micro on the power (relay) board located in the base of the unit. These two boards exchange data continuously through a 4-wire low voltage connector carrying Ground, 5 VDC power, a Data line, and Neutral. When data transfer between them is interrupted or corrupted, the master micro detects the failure and triggers the F-8 fault to halt operation.

The most common root cause of this error is moisture on the 4-wire low voltage connector that links the door-mounted control board to the base-mounted relay board. This connector runs through the door hinge area, where it is exposed to condensation and steam during wash cycles. Even a small amount of moisture bridging the connector pins can disrupt the 5 VDC data signal, causing the communication link to drop. Because this is a low-voltage data circuit, any resistance introduced by corrosion or water contamination is enough to cause errors.

Less commonly, the fault can be caused by a damaged or improperly seated connector, a failed control board, or a failed relay board. However, technicians should always inspect and dry the 4-wire connector first before replacing components, since physical contamination accounts for the majority of F-8 occurrences and a component swap will not resolve the problem if moisture is the underlying cause.

Source: manufacturer service documentation.

Common causes of F-8

  1. 01

    Moisture on the 4-wire low voltage connector

    Wiring / connection

    Steam and condensation from wash cycles can wet the connector that runs between the door control board and the base relay board. Inspect the connector for water droplets, corrosion, or white residue on the pins, which indicates prior moisture exposure.

  2. 02

    Corroded or damaged connector pins

    Part replacement

    Repeated moisture exposure can oxidize or corrode the connector pins over time, creating enough resistance on the data or 5 VDC line to disrupt communication even after the connector is dry. A visual inspection under good lighting will reveal discoloration or pitting on the contacts.

  3. 03

    Improperly seated or disconnected connector

    Wiring / connection

    The 4-wire connector may have come loose due to vibration during the wash cycle or during a prior service visit. Check that the connector is fully seated and latched on both the control board and relay board ends.

  4. 04

    Failed relay (power) board

    Part replacement

    If the 4-wire connector is dry, undamaged, and fully seated but the F-8 error persists, the slave 1 micro on the relay board may have failed. This board will need to be replaced if all connector-related causes have been ruled out.

  5. 05

    Failed main control board

    Part replacement

    In rare cases, the master micro on the door-mounted control board is the source of the communication failure. This is typically the last component to suspect after confirming the connector and relay board are both in good condition.

See the test procedure for each cause

Frequently asked questions about F-8

What does F-8 mean on a Dacor dishwasher?
F-8 indicates a communication failure between the main control board in the door and the relay board in the base of the dishwasher. The two boards communicate over a 4-wire low voltage connector carrying Ground, 5 VDC, Data, and Neutral signals. When that data transfer is interrupted or fails, the dishwasher stops and displays F-8. Moisture on the connector is the most common cause.
How do I fix an F-8 error on my Dacor dishwasher?
Start by locating the 4-wire low voltage connector that runs between the control board in the door and the relay board in the base. Disconnect it, inspect it for moisture, corrosion, or loose pins, and allow it to dry completely before reconnecting. If the connector looks clean and is fully seated but the error returns, the relay board or control board may need to be replaced.
Will resetting my Dacor dishwasher clear the F-8 error?
A reset may temporarily clear the F-8 code, but if the underlying cause such as moisture or a damaged connector is not addressed, the error will return. Resetting the dishwasher without inspecting the 4-wire connector is not a lasting fix. Always resolve the root cause before relying on a reset.
Is it safe to keep using my Dacor dishwasher when F-8 is displayed?
No, the dishwasher should not be operated while F-8 is active. The error means the control board and relay board cannot communicate, which means the appliance cannot properly manage its wash cycle functions. Attempting to run cycles in this condition could cause incomplete operation or additional faults.
How much does it cost to repair a Dacor dishwasher F-8 error?
If moisture is the cause and the connector only needs to be dried and reseated, repair costs may be limited to a diagnostic service call, typically in the range of $75 to $150. If a relay board or control board needs to be replaced, total repair costs including parts and labor can range from $200 to $500 or more depending on parts pricing and local labor rates.

Related Dacor dishwasher codes

All Dacor dishwasher codes
View all 15 Dacor dishwasher codes

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass