E34
Bosch Washing Machine
Severity: ModerateWhat Does This Error Mean?
Error code E34 on a Bosch washer indicates a fault in the motor control circuit. The control board has detected an abnormal condition in the circuit that drives the drum motor. This could be a failed motor control component on the main board, a problem with the motor itself, or a wiring fault between the board and the motor. Your washer will stop or refuse to start a cycle. A reset sometimes clears a transient fault, but repeated E34 usually requires a hardware repair.
Affected Models
- Bosch Front-Load Washers
- Bosch Serie 4 washers
- Bosch Serie 6 washers
- Bosch Serie 8 washers
- Bosch WAx series models
Common Causes
- A failed motor driver component (TRIAC or IGBT) on the main control board
- A failing drum motor drawing excessive current and tripping the control circuit
- A wiring fault or short in the motor supply wires causing abnormal current readings
- Worn motor brushes creating arcing and damaging the motor control circuit
- A power surge that damaged motor driver components on the control board
How to Fix It
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Perform a hard reset. Unplug the washer for 10-15 minutes and plug it back in. If E34 was caused by a temporary overcurrent event, the reset may clear the fault and allow normal operation.
If E34 returns within the first cycle after a reset, a component has failed.
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Check for an overloaded drum. Remove the laundry and try running an empty cycle. An excessively heavy load can stall the motor momentarily, causing an overcurrent event that sets E34.
If the empty cycle runs without E34, reduce your load size and try again.
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Inspect the wiring between the motor and the control board. Look for any burned, melted, or chafed wires. A shorted motor wire can feed current back into the board and damage the motor driver components.
Any wire showing burn marks must be repaired before the machine is run again.
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Check the motor brushes (on brushed motor models). Access them from the back panel. Short brushes create arcing which generates voltage spikes that can damage the control board's motor driver circuit.
Replacing brushes ($10-$25) is far cheaper than replacing the control board ($150-$400).
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If wiring and brushes are fine, have a technician test the motor's current draw and the control board's motor driver output. This distinguishes a motor problem from a board problem and prevents replacing the wrong component.
On brushless inverter motor models, the inverter section of the board is what fails — boards for these models can cost more than standard boards.
When to Call a Professional
E34 requires electrical testing to distinguish between a motor fault and a control board fault. Replacing the wrong component is expensive and time-consuming. A Bosch-certified technician can test both the motor and the board output in one visit. Expect $150-$400 for a confirmed repair depending on whether the motor or board needs replacement.
Frequently Asked Questions
What is a TRIAC in a washing machine control board?
A TRIAC is an electronic component on the control board that regulates the electrical power going to the motor. Think of it as a high-speed electronic switch that can vary how much power the motor receives. When a TRIAC fails, it either stops delivering power (motor will not run) or delivers full power all the time (motor runs at one speed only). Failed TRIACs are a common cause of E34 on older Bosch washers.
Can I fix E34 myself?
A reset and load reduction are DIY-friendly. Motor brush replacement requires opening the back panel but is manageable for a handy person. Testing and replacing motor drivers on a control board requires electronics knowledge and tools. For anything beyond brushes and connectors, a technician is the safer choice.
How much does it cost to fix E34?
Motor brushes: $10-$25 for parts. A main control board: $150-$400 depending on model. A drum motor: $100-$250. Technician diagnosis and repair: $150-$400 total.