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Error code reference

Electrolux Dryer Error Code H4/B4

Line wiring error.

Electrolux codesElectrolux dryer codes

Line wiring error.

First step from the service manual

Ensure correct wiring on Dryer Terminal Block

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

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What H4/B4 means on a Electrolux dryer

The H4/B4 error code on an Electrolux dryer indicates a line wiring error, meaning the control board has detected an issue with the incoming power supply wiring at the dryer's terminal block. This error is specifically related to how line voltage is connected to the appliance, not an internal component failure. The terminal block is the point where the household power supply connects to the dryer, and any miswiring, loose connection, or incorrect configuration at that block can trigger this fault.

Electrolux dryers are designed to operate on a specific voltage configuration, and the control system monitors the incoming power lines to confirm proper wiring. If the voltage on one or more legs of the supply is absent, reversed, or improperly connected at the terminal block, the dryer will detect this as a line wiring error and display H4/B4 to prevent operation. This is a protective measure to avoid damage to internal components or a safety hazard.

The most common scenario that produces this code is an incorrect or incomplete installation of the power cord at the terminal block, including swapped wires, a missing neutral connection, or a loose terminal screw. It can also occur after a power cord replacement where the wiring configuration was not properly followed. Because this error involves line voltage, any inspection or correction of the terminal block wiring should be performed with the dryer fully unplugged from the power supply.

Source: manufacturer service documentation.

Common causes of H4/B4

  1. 01

    Incorrect power cord wiring at terminal block

    Wiring / connection

    Wires from the power cord connected to the wrong terminals during installation or replacement are the most frequent cause of H4/B4. Check that each wire is connected to its correct terminal according to the wiring diagram located on or near the terminal block cover.

  2. 02

    Loose or improperly secured terminal connection

    Wiring / connection

    A wire that is not firmly secured under its terminal screw can cause intermittent or complete loss of voltage on that line, triggering the error. Inspect each terminal screw for tightness with the dryer unplugged.

  3. 03

    Wrong power cord type installed

    Part replacement

    Installing a 3-wire cord in a home with a 4-wire outlet, or vice versa, without adjusting the neutral bonding configuration can produce a line wiring error. Verify that the cord type matches the home's outlet and that the terminal block is configured correctly for that cord.

  4. 04

    Damaged or broken power cord wire

    Part replacement

    A wire inside the power cord that has broken internally or at the terminal connection point can interrupt one leg of the supply voltage. Inspect the cord and each wire end for signs of damage, burning, or fraying.

  5. 05

    Faulty or failed control board

    Part replacement

    If the terminal block wiring is confirmed to be correct and secure, a control board that is incorrectly sensing the incoming line voltage may be responsible for the error. This is a less common cause and should only be considered after all wiring has been inspected and verified.

See the test procedure for each cause

Frequently asked questions about H4/B4

What does H4/B4 mean on a Electrolux dryer?
The H4/B4 error code indicates a line wiring error detected at the dryer's terminal block, which is where the power cord connects to the appliance. The control board has determined that the incoming power supply wiring is not configured correctly. This code is a protective fault that prevents the dryer from operating until the wiring issue is resolved. The first step is to inspect the connections at the terminal block with the dryer unplugged.
How do I fix the H4/B4 error on my Electrolux dryer?
Start by unplugging the dryer completely before doing anything else. Remove the terminal block cover and carefully inspect each wire connection to confirm the correct wire is on the correct terminal and that every terminal screw is tight. If a wire is loose, secured to the wrong terminal, or damaged, correct it before restoring power. If the wiring appears correct and the error persists, a power cord replacement or professional electrical inspection may be needed.
Is the H4/B4 error on an Electrolux dryer a safety concern?
Yes, a line wiring error should be treated as a safety concern. Incorrect wiring at the terminal block can create a shock hazard or fire risk. Always unplug the dryer before inspecting any wiring, and if you are not comfortable working with appliance wiring, contact a qualified appliance repair technician or electrician.
Will resetting my Electrolux dryer clear the H4/B4 error?
Resetting the dryer by unplugging it for a few minutes may temporarily clear the display, but the H4/B4 error will return if the underlying wiring issue has not been corrected. Because this is a fault based on a real condition at the terminal block, the error will continue to appear until the wiring is inspected and any problems are resolved.
How much does it cost to fix the H4/B4 error on an Electrolux dryer?
If the fix is simply correcting a loose or swapped wire at the terminal block, the cost may be minimal or involve no parts at all. If a new power cord is needed, replacement cords typically range from around 15 to 50 dollars depending on the cord type. If a technician is needed to diagnose and repair the issue, expect to pay between 75 and 200 dollars for labor and any necessary parts.

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