What E:27 Means
E:27 is logged when the water switch, or the little motor that drives it, does not respond as expected, and the wash closes out early as a result. Bosch pairs this with a second cause on the same row: mains voltage sitting continuously below 85 volts in the US, which starves the diverter motor and produces the same symptom. The chart separates the two with a voltage reading taken at the switch.
Common Causes of E:27
- Water switch or its drive motor failed
- Sustained low mains voltage at the appliance
- Power module not delivering the correct voltage to the switch
🔧 One Safe Check You Can Try
Note whether kitchen lights dim when the dishwasher, disposer or microwave start, since the chart names sustained low supply voltage as a cause and that is a household wiring matter worth an electrician rather than an appliance visit.
⚠ Why You Shouldn't Go Further Than That
- One of the two documented causes is not in the dishwasher at all, and pulling the machine apart will not find it.
- The decisive test is a live voltage reading taken at the water switch terminals while the programme runs, which is not a safe homeowner measurement.
- House wiring that sags under load is licensed electrician work in most jurisdictions, not an appliance repair.
- Running the machine repeatedly on low voltage stresses every motor in it, so repeated restarts make the eventual bill larger.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.