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Error code reference

Electrolux Dryer Error Code H3/B3

Power supply amplitude out of range (too LOW).

Electrolux codesElectrolux dryer codes

Power supply amplitude out of range (too LOW).

First step from the service manual

Refer to test (7)

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

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What H3/B3 means on a Electrolux dryer

The H3/B3 error code on an Electrolux dryer indicates that the power supply amplitude has been detected as too low. This means the control board is sensing that the incoming AC voltage is falling below the acceptable operating threshold. The dryer's main control board continuously monitors the amplitude of the power supply waveform, and when that amplitude drops outside the expected range on the low end, the board triggers this fault code to protect the appliance and alert the user to an electrical supply problem.

The root cause of this fault almost always originates outside the dryer itself. Low voltage conditions can result from issues at the home's electrical panel, a weak utility supply, a failing circuit breaker, or high-resistance connections at the outlet or terminal block. For electric dryers operating on a 240V circuit, a partial power loss where one leg of the supply drops significantly can also produce this code. Wiring degradation, loose connections at the wall receptacle, or undersized wiring for the circuit can all contribute to amplitude sag under load.

The first diagnostic step for H3/B3 is to perform test (7) as outlined in the dryer's diagnostic procedure. This test is designed to evaluate the incoming power supply characteristics and confirm whether the fault is originating from the external electrical supply or from the control board's sensing circuit. Technicians should verify actual line voltage at the outlet and at the dryer's terminal block under load conditions before replacing any components.

Source: manufacturer service documentation.

Common causes of H3/B3

  1. 01

    Low incoming line voltage

    Wiring / connection

    The household electrical supply to the dryer circuit is delivering voltage below the acceptable range. This can happen during periods of high electrical demand or due to utility supply issues, and can be confirmed by measuring voltage at the wall outlet with a multimeter.

  2. 02

    Failing or tripped circuit breaker

    Part replacement

    A weak or partially tripped double-pole breaker can cause one or both legs of a 240V circuit to sag, reducing the overall voltage amplitude. The breaker may appear to be in the ON position while still failing to deliver full voltage.

  3. 03

    Loose or corroded outlet or terminal block connections

    Wiring / connection

    High-resistance connections at the wall receptacle or at the dryer's internal terminal block can cause voltage to drop under load. Inspect connections for scorching, corrosion, or looseness.

  4. 04

    Undersized or damaged supply wiring

    Part replacement

    Wiring that is too small for the circuit load, or wiring that has been damaged or degraded, can result in significant voltage drop when the dryer draws current. This requires inspection of the circuit wiring from the panel to the outlet.

  5. 05

    Faulty main control board

    Part replacement

    In rare cases, the control board's voltage sensing circuit may be malfunctioning and reporting a false low-amplitude fault even when supply voltage is within range. This should only be considered after the external power supply has been confirmed to be correct.

See the test procedure for each cause

Frequently asked questions about H3/B3

What does H3/B3 mean on a Electrolux dryer?
The H3/B3 code means the dryer's control board has detected that the incoming power supply amplitude is too low. The board monitors the AC voltage waveform continuously, and this fault is triggered when voltage falls below the acceptable operating range. The issue typically points to a problem with the home's electrical supply rather than a failed dryer component. Diagnostic test (7) is the first step for evaluating this condition.
Can I fix the H3/B3 error myself?
Some causes of H3/B3 can be addressed by a knowledgeable DIYer, such as checking for a tripped breaker or inspecting the outlet for loose connections. However, working with 240V dryer circuits carries serious shock and fire hazards, so any work beyond resetting the breaker should be done by a licensed electrician or qualified appliance technician. Measuring live voltage at the outlet with a multimeter is a safe first step if you are comfortable using one properly.
Will resetting the dryer clear the H3/B3 error?
Resetting the dryer by disconnecting power may temporarily clear the error code, but the fault will return if the underlying low-voltage condition is still present. The H3/B3 code is triggered by a real-time measurement of the power supply, so it will reappear as soon as the dryer powers on and detects the same low amplitude. The root cause in the electrical supply must be corrected for the error to stay cleared.
Is it safe to run the dryer when H3/B3 is displayed?
It is not recommended to operate the dryer while this error is active. Running a dryer on low voltage can cause motors and heating elements to draw excessive current, which can overheat components and create a fire risk. The dryer may also perform poorly or fail to complete cycles. Address the power supply issue before resuming normal use.
How much does it cost to repair the H3/B3 error on an Electrolux dryer?
Repair costs vary depending on the cause. If the issue is a failing circuit breaker, replacement costs typically range from $50 to $150 including an electrician's labor. Outlet replacement or wiring repairs can range from $100 to $300 or more depending on the extent of the work. If the dryer's main control board is ultimately found to be at fault, board replacement parts and labor can range from $150 to $400. Getting the power supply evaluated first can prevent unnecessary part replacements.

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