Bosch dishwasher — Error Code E27
The main control board is sensing inadequate voltage levels.
What it means
The E27 error on a Bosch dishwasher signals an under-voltage condition. Your machine's main control module keeps a constant watch on incoming power to ensure the heating element and wash motor function safely. If the AC supply dips below the required operational floor (typically under 105V on a 120V circuit), the board shuts down the cycle and flashes E27. This safety measure prevents internal components from suffering damage during a brownout. Usually, this isn't an internal machine failure but rather an external power issue, such as a grid fluctuation, circuit overload, or compromised wiring at the junction box.
Likely Causes
- 1 Voltage Fluctuations (Brownout)Regional power grid instability or significant electrical demand in your home can push voltage levels below the standard 120V requirement.
- 2 Circuit OverloadOperating high-wattage devices, such as space heaters during a chilly Bend winter or large kitchen appliances, on the same circuit as your dishwasher can deprive it of the necessary voltage.
- 3 Damaged Junction Box ConnectionsIf the wire nuts inside the dishwasher's junction box are loose or show signs of burning, they create electrical resistance that causes a voltage drop at the control board.
- 4 Compromised Outlet or CordA worn-out wall receptacle or a damaged power cord can restrict current flow, causing the sensor to trigger the E27 alert.
- 5 Control Board FailureIf your multimeter confirms a steady 120V supply under load but the error persists, the sensing circuitry on the main control board has likely reached the end of its life.
How to clear / reset
To temporarily reset the E27 code, perform a hard power cycle. Switch off the dishwasher, then either unplug the unit or flip the dedicated circuit breaker in your service panel. Keep the power disconnected for roughly 5 to 10 minutes to allow the capacitors on the control board to drain. Afterward, restore power and restart the machine. If the error was caused by a momentary grid flicker, the unit should resume normal operation. However, if the issue is rooted in faulty wiring or a circuit overload, the E27 code will reappear as soon as the heater or wash pump pulls enough current to cause another voltage drop.
Common replacement parts
When to call a pro
Contact us if you have confirmed that your home circuit provides a consistent 120V, yet the E27 error remains. Repairing burnt junction box wiring or replacing a main control board involves complex electrical work and poses a safety risk. Our A-Fix Service technicians are equipped to perform accurate load testing and component replacement. We charge a $90 diagnostic fee (which is waived if you proceed with the repair) and provide a 1-year warranty on all parts and labor.
FAQs
What is the typical cost for an E27 repair?
If the issue is external, you may need an electrician. For repairs involving the dishwasher's junction box or power cord, costs generally range from $120-$180. A main control board replacement typically ranges from $250-$400+ including the labor.
Can I perform this repair myself?
You can safely check your circuit breaker and test your wall outlet with a multimeter. If the outlet reads 120V, avoid further disassembly. Checking the junction box or control board internals is best left to a professional to avoid electrical hazards.
Does the E27 code resolve automatically?
Yes, if the error resulted from a transient brownout, the dishwasher will often clear the fault once you restore steady 120V power and cycle the unit.
Is it harmful to run the dishwasher during low voltage?
Yes. Operating motors and electronic boards during brownout conditions causes increased amperage, which produces excessive heat and can permanently damage the wash pump or control board.
How much time is required for this repair?
Once the necessary parts are available, a technician can usually replace a faulty control board or repair a junction box within 30 to 60 minutes.
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