Error Code E:29

Error Code E:29: Low Mains Voltage Detection

This error code, E:29, indicates a critical electrical issue detected by the dishwasher’s main control unit. Specifically, the internal diagnostics have registered that the incoming electrical supply voltage is significantly too low, falling below the required operational threshold of 170 Volts (V). This insufficient voltage supply can prevent the heating element, pump motors, and control board from operating correctly, leading to cycle failure.

Applicable Brands: Bosch, Siemens, Neff, Constructa, Gaggenau

Recommended Troubleshooting Steps

When encountering error E:29, the issue is typically external to the dishwasher unit itself, relating to the household wiring or circuit capacity. Please perform the following checks in order:

1. Investigate Simultaneous Power Consumption:

   • The most common cause for intermittent low voltage is high demand on the household circuit breaker. The electrical circuit supplying the dishwasher may be overloaded by other high-wattage appliances running at the same time.
   • Action: Turn off or unplug other major appliances connected to the same circuit (e.g., electric ovens, clothes dryers, high-power heaters, or induction cooktops). Restart the dishwasher cycle. If the error clears, the issue is circuit overload, and you should utilize the circuit capacity more evenly.

2. Test Alternative Power Outlet Connection:

   • While unlikely to resolve a consistent low voltage issue, a faulty wall socket or extension cord could be introducing resistance, causing a voltage drop.
   • Action: Unplug the dishwasher completely from its current outlet. Plug the unit directly into a known, verified working power outlet in a different area of the house or kitchen, ensuring this new outlet is not sharing a circuit with other high-demand appliances. Attempt to run a short cycle.

3. Contact a Certified Electrician:

   • If the E:29 error persists even when no other appliances are running, the problem lies within the home’s fixed electrical installation (the wiring, the breaker panel, or the service entrance connection). The dishwasher requires a stable supply of at least 170V to operate reliably.
   • Action: If the troubleshooting steps above do not resolve the low voltage condition, cease attempting to operate the appliance and contact a qualified, certified electrician. They will need to test the voltage delivery at the wall outlet and potentially inspect the home’s main service panel or internal wiring infrastructure to correct the persistent voltage drop.