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Error code reference

Ariston Oven Error Code ER71

I2C communication fault

Ariston codesAriston oven codes

I2C communication fault - display board communication defective.

First step from the service manual

Replace the display board.

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

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What ER71 means on a Ariston oven

ER71 on an Ariston oven indicates a fault in the I2C communication bus between the main control board and the display board. I2C (Inter-Integrated Circuit) is a serial communication protocol used to transfer data between internal electronic components. When this communication link breaks down or becomes unreliable, the control system detects the failure and triggers ER71 to alert the technician that the display board is not responding correctly to the main board's signals.

The display board in these ovens does more than show temperatures and settings. It handles user input, relays commands to the main control board, and receives status data back for display. A breakdown in I2C communication can be caused by a failed display board, corroded or loose ribbon cable connections between the boards, damaged wiring harnesses, or in some cases a fault originating on the main control board itself that prevents it from initiating the communication handshake properly.

Because the first recommended diagnostic step is to replace the display board, the display board itself is the most probable source of the fault. However, before replacement, technicians should inspect the connector pins and ribbon cables for corrosion, physical damage, or poor seating, as a loose connection can mimic a full board failure. If replacing the display board does not resolve the error, attention should shift to the wiring harness and ultimately the main control board.

Source: manufacturer service documentation.

Common causes of ER71

  1. 01

    Failed display board

    Part replacement

    The display board is the most likely cause of ER71. Internal component failure on the board can break the I2C communication link entirely, and replacement is the primary recommended diagnostic step.

  2. 02

    Loose or disconnected ribbon cable

    Wiring / connection

    The ribbon cable or connector linking the display board to the main control board may have worked loose or become unseated. Inspect the connector at both ends for proper seating and any signs of physical damage.

  3. 03

    Corroded connector pins

    Wiring / connection

    Moisture or heat exposure inside the oven cavity can cause corrosion on the I2C communication connectors, increasing resistance and disrupting signal transmission. Check the pins visually and clean carefully if corrosion is present.

  4. 04

    Damaged wiring harness

    Part replacement

    The wiring between the display board and the main control board may be chafed, pinched, or broken, interrupting the I2C data lines. Trace the harness visually for any damage along its full length.

  5. 05

    Faulty main control board

    Part replacement

    If replacing the display board and inspecting the connections does not clear the error, the main control board may be failing to initiate or sustain the I2C communication handshake. This is a less common cause but should be considered if other steps have not resolved the fault.

See the test procedure for each cause

Frequently asked questions about ER71

What does ER71 mean on a Ariston oven?
ER71 on an Ariston oven signals an I2C communication fault between the display board and the main control board. I2C is the internal protocol these two boards use to exchange data. When the communication fails or becomes defective, the oven logs ER71 to indicate the display board circuit is not responding correctly. The display board itself is the most common source of this fault.
Can I fix ER71 on my Ariston oven myself?
A knowledgeable DIYer can start by checking that all ribbon cables and connectors between the display board and the main control board are fully seated and free of corrosion. If that does not resolve the error, the display board will need to be replaced, which involves disconnecting the old board and installing a compatible replacement. Working on internal oven electronics requires the appliance to be fully disconnected from power before any inspection or repair.
Is it safe to use my Ariston oven while ER71 is displayed?
It is not advisable to continue using the oven while ER71 is active. A communication breakdown between the display board and the main control board can prevent the oven from accurately receiving or displaying user commands, which may lead to unpredictable operation. The oven should be powered off and left unused until the fault is diagnosed and repaired.
How much does it cost to repair ER71 on an Ariston oven?
Repair costs depend on whether the issue is a simple connector problem or requires a replacement display board. A replacement display board for an Ariston oven typically costs in the range of $80 to $200 for the part alone. Adding professional labor, the total repair bill can range from $150 to $350 or more depending on your location and service provider.
Will resetting my Ariston oven clear the ER71 error?
A power reset, such as switching off the oven at the circuit breaker for a few minutes, may temporarily clear ER71 if the fault was caused by a transient communication glitch. However, if the display board has an internal failure or a connector is damaged, the error will return once the oven powers back on. A reset is worth attempting as a first step, but a lasting fix requires addressing the underlying hardware fault.

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