Bosch dishwasher E27 error
Usable, but not working properly
The supply voltage reaching the dishwasher has dropped below the level it needs, so it halts the cycle. Bosch describes this as the mains falling to roughly 170 volts or lower. It reports a problem with the electricity supply rather than a fault inside the machine. The dishwasher is plugged into an extension lead or a multi-way adaptor shared with other high-current appliances is the most common cause.
- Difficulty
- Some experience
- Time needed
- About 20 min
- Checks
- 4 steps
The same fault is shown as E9001, E:90-01 on some Bosch series, depending on the display and the model year.
Before you start
- A plug or socket that runs warm or shows scorching is a fire risk. Stop using that socket and have an electrician inspect it before running the machine again.
- Do not open the plug, the socket or the fused spur to investigate. Measuring a live supply under load is electrician's work.
- This code reports a supply problem. Do not fit a larger fuse or bypass anything to make it go away.
What it means
The supply voltage reaching the dishwasher has dropped below the level it needs, so it halts the cycle. Bosch describes this as the mains falling to roughly 170 volts or lower. It reports a problem with the electricity supply rather than a fault inside the machine.
Most likely causes
Ordered from most to least common, with what each one looks like:
| Cause | How likely | What you would see |
|---|---|---|
| The dishwasher is plugged into an extension lead or a multi-way adaptor shared with other high-current appliances | high | A kettle, tumble dryer or heater is on the same lead or the same spur |
| The property is fed by a weak or overloaded supply that sags when a heating element switches on | medium | Lights dim briefly elsewhere in the kitchen at the moment the code appears |
| A loose connection in the plug, socket or fused spur is dropping voltage under load | medium | The plug or socket feels warm, or is discoloured around the pins |
| A generator, inverter or voltage stabiliser is supplying the machine and cannot hold the voltage under heater load | low | The property runs on an off-grid or backup supply when the fault occurs |
Fix steps
-
Check whether the dishwasher is running through an extension lead, adaptor or multi-way block rather than a dedicated wall socket or fused spur.
Expected result The machine is connected directly to its own socket with nothing else sharing it. If it does not, go to step 2.
-
Move the dishwasher onto its own socket, or unplug whatever else shares the lead, and run a cycle with no other heavy appliance running.
Expected result The cycle completes without the code, which points at loading rather than the appliance. If it does not, go to step 3.
-
Feel the plug and socket after a few minutes of running and look for discolouration, scorching or a warm plug body.
Expected result Both stay cool and unmarked. If it does not, go to step 4.
-
If the plug or socket runs warm, or the code returns on a dedicated socket with nothing else running, stop and book a qualified electrician to measure the supply voltage under load.
Expected result The electrician can confirm whether the supply is genuinely sagging and where the voltage is being lost.
Parts needed
No replacement parts are needed for the checks above. This fault is usually cleared without fitting anything new.
When to call a technician
Call a qualified technician if you work through every step above and the code comes back, if you find water where it should not be, or if any part of the job needs the machine powered up with panels removed. A repeat fault after a correct repair usually points at the control board rather than the part you replaced.
Common questions
What does E27 mean on a Bosch dishwasher?
The supply voltage reaching the dishwasher has dropped below the level it needs, so it halts the cycle. Bosch describes this as the mains falling to roughly 170 volts or lower. It reports a problem with the electricity supply rather than a fault inside the machine. The dishwasher is plugged into an extension lead or a multi-way adaptor shared with other high-current appliances is the most common reason for it.
Can I keep using the dishwasher?
You can usually still run the machine, but it will not be working correctly and the fault will keep coming back until it is fixed.
Is this something I can fix myself?
Partly. The first checks are straightforward, but the later ones need no special tools and some confidence taking panels off. Budget about 20 minutes.
Models this applies to
- SMS All codes for this model
- SMV All codes for this model
- SMI All codes for this model
- SHP All codes for this model
- SHE All codes for this model
Related codes on the same machines
- E12 Limescale and grease have built up on the heating surfaces to the point where the machine reports that it needs descaling before it can heat water reliably.
- E15 Water has collected in the tray underneath the dishwasher and a float in that tray has tripped the leak protection system, which shuts the machine down and runs the drain pump to keep the leak from spreading.
- E18 The machine asked for water and not enough arrived in the time it allows, so it stopped the cycle rather than washing without a proper fill.
- E21 The circulation pump that drives water up to the spray arms is reported as blocked, so the machine stops rather than running the motor against an obstruction.
- E22 The filters in the base of the tub are blocked enough to starve the circulation pump, or the filter assembly is not locked into place, so the machine cannot move water round the wash arms properly.
- E23 The machine has detected a fault in the waste water pump circuit.