Bosch SHP78CM5N — E27 or E9001: incoming voltage too low. E27/E9001 is Bosch's low incoming-voltage code; it is electrically distinct from E23/E6101 drain-pump failure. Preserve the exact display, programme stage and behaviour before changing anything. Turn the dishwasher circuit off for 30 seconds once. If the code returns, leave the appliance off and have the household supply checked by a qualified electrician before Bosch service. Cancel the programme, isolate electrical power, close the water valve for any inlet or leak symptom and let the tub cool. Wear gloves near filters because hidden glass may be present; never tilt a built-in unit or open its base, door skin, pumps or wiring.
Models covered
Safety first
- Cancel the programme, isolate electrical power, close the water valve for any inlet or leak symptom and let the tub cool. Wear gloves near filters because hidden glass may be present; never tilt a built-in unit or open its base, door skin, pumps or wiring.
What the symptom may indicate
Checks in the right order
- Capture the starting point
Photograph or note “E27 or E9001: incoming voltage too low”, the selected programme, remaining water and what happened immediately before it.
- Make the appliance safe
Cancel the programme, isolate electrical power, close the water valve for any inlet or leak symptom and let the tub cool. Wear gloves near filters because hidden glass may be present; never tilt a built-in unit or open its base, door skin, pumps or wiring.
- Follow the official user check
Turn the dishwasher circuit off for 30 seconds once. If the code returns, leave the appliance off and have the household supply checked by a qualified electrician before Bosch service.
- Retest once and decide
If the exact condition clears, observe one supervised normal cycle. If it returns, preserve the evidence and use authorised service rather than repeating resets or guessing a part.
Stop and get qualified help when
- Stop immediately for smoke, burning smell, a hot plug, damaged cable, breaker trip, uncontrolled filling, water near electrics, an active leak, escaping steam or the exact fault returning after one documented test.
Next step
Repair, replace a part, or arrange a diagnosis?
Use the checks and stop conditions above to choose a cautious next step. A symptom alone never proves that the appliance has failed.
Resolve it without buying anything
Complete the 4 user-accessible checks in order. If normal operation returns and no warning sign remains, no replacement is indicated.
Replace only the confirmed part
If the checks isolate a worn or blocked component, match its complete reference to the exact appliance model before ordering.
This guide does not identify a replacement part. Do not order a generic component from the symptom alone.
Arrange a diagnosis before replacing the appliance
Stop at any warning sign listed above. A qualified diagnosis should confirm that repair is unsafe, unavailable or uneconomical before an appliance replacement is considered.
Sources used
- Bosch — Bosch's official manual, support article or exact model page documents “E27 or E9001: incoming voltage too low” and the bounded user action retained here.
- Bosch — Bosch's official manual, support article or exact model page documents “E27 or E9001: incoming voltage too low” and the bounded user action retained here.
- Bosch — Bosch's official manual, support article or exact model page documents “E27 or E9001: incoming voltage too low” and the bounded user action retained here.
- Bosch — Bosch's official manual, support article or exact model page documents “E27 or E9001: incoming voltage too low” and the bounded user action retained here.
Last checked: 30 August 2026