Bosch · Dishwasher Moderate

E27 — Low supply voltage

Per Bosch's official US error-code page, E27 means the house power supply to the unit is too low; Bosch recommends contacting an electrician to check the incoming voltage.

Keep using it?
Yes, with caution
DIY difficulty
Easy
Verified against
bosch-home.com ↗

How to fix it

  1. Measure outlet voltage at the dishwasher (should be 108-132 V).
  2. Measure under load (with heater on) to see if it sags below 108 V.
  3. Confirm the dishwasher is on a dedicated 15 A or 20 A circuit per spec.
  4. Tighten outlet, junction box, and breaker terminals (with power off).
  5. If voltage still sags, have an electrician evaluate the supply.

Why it happens

Typical signs: Random shutdowns · E27 in the evening when other appliances run · Cycle never finishes

  • Brownout / undervoltage at outlet House voltage sagging during heavy load periods.
  • Shared circuit overload Dishwasher sharing a circuit with disposer or microwave.
  • Loose outlet or junction box connection High-resistance neutral causing voltage drop under load.
  • Extension cord or undersized wiring Long undersized run feeding the unit.

More Bosch dishwasher codes

E01 E01 — Control board fault E02 E02 — Heating element / NTC sensor fault E03 E03 — Water not heating E04 E04 — Water flow / flow meter fault E05 E05 — Overfill / float switch tripped E06 E06 — Door-Closure or Aqua (Turbidity) Sensor Fault

All Bosch codes → All dishwasher codes →

Frequently asked questions

What does the E27 code mean on a Bosch dishwasher?

Per Bosch's official US error-code page, E27 means the house power supply to the unit is too low; Bosch recommends contacting an electrician to check the incoming voltage.

What causes the E27 code on a Bosch dishwasher?

Brownout / undervoltage at outlet: House voltage sagging during heavy load periods. Shared circuit overload: Dishwasher sharing a circuit with disposer or microwave. Loose outlet or junction box connection: High-resistance neutral causing voltage drop under load.

Is it safe to keep using a Bosch dishwasher with a E27 error?

Yes, with caution. This is rated a moderate-severity fault.

How do I fix E27 on a Bosch dishwasher?

Measure outlet voltage at the dishwasher (should be 108-132 V). Measure under load (with heater on) to see if it sags below 108 V. Confirm the dishwasher is on a dedicated 15 A or 20 A circuit per spec.

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician. Verified against manufacturer documentation: bosch-home.com.