The reading in two sentences
Read E9001 as this: the supply from the house to the machine is too low. Do not keep running it: the control has already judged the supply unfit, and heating on a low supply is what damages components. You can settle whether this is a one-off or a real fault yourself; naming the failed part is not owner work.
Error codes
Reference| Code | Meaning |
|---|---|
| E9001 | The house power supply to the unit is too low. |
What else is happening when this shows
- The display flickers or resets as the machine runs — A control losing its supply momentarily records exactly this.
- The code appears at the moment a heavy load switches on — Heating and motor starts are when a marginal supply shows itself.
- NEAR MISS — nothing works at all and there is no display — That is a dead supply rather than a marginal one, and it is a different check: breaker, then outlet.
What triggers E9001, most likely first
- An extension lead or a multi-way adaptor in the path — First because it is the commonest and it is removed in a minute: a lead or a strip drops voltage under a heating load, and the machine sees that drop as a supply below its range.
- Another heavy load on the same branch circuit — A dishwasher expects the supply the manufacturer specifies with a margin for its heating stage, and sharing the branch with a kettle or a heater removes that margin.
- A control board that misreads the supply it is given — It is last because it is the least likely, and the only way to reach it honestly is to prove the supply itself is sound first.
The order to work through
- Run the machine with the rest of the circuit switched off — If the programme completes, the branch was the answer and no part needs buying.
- Trace the machine to the wall and remove anything in between — No strip, no adaptor, no extension: that path is the first suspect and it is free to eliminate.
- Trace the appliance back to the wall by eye — Anything between the plug and the outlet — a strip, an adaptor, a long lead — is the first thing to remove from the picture.
- Body: Separate the appliance from the building first: one run with the rest of the circuit switched off answers more than any measurement.
The reset and the checks that follow it
- Plug the appliance straight into its own wall outlet — No strip, no adaptor, no extension. This one change resolves a good share of supply codes on its own.
About 10 min
- Connect the machine straight to its own wall outlet — Then run the same programme that failed and watch whether it reaches the heating stage.
About 15 min
- Run the appliance with the rest of the circuit idle — Switch off the other heavy loads on the same breaker and repeat whatever produced the code.
About 45 min
- STOP HERE — supply measurement is licensed work — Do not open an outlet or a terminal block to check a voltage. That is where an owner check ends.
Before a panel comes off
Safety
Unplug the machine or switch off its breaker before any panel comes off — a capacitor can hold a charge after the power is off. Expect hot water: let a heated cycle cool before opening the door or lifting the filter, and never work round the door interlock to start a cycle.
Where an owner check ends
Call as soon as the code survives a dedicated outlet and an otherwise idle circuit.
Other codes on a Bosch dishwasher
What is deliberately not here
Treat this as the general Bosch dishwasher reading. It stops short of anything model-specific — part numbers, harness colours, connector layouts and service-mode entry — because those differ by family and a technician takes them from the rating plate rather than from a code. A family- or model-specific page, where one exists, is linked from the code index below and is the closer answer.
Links: - [Bosch dishwasher error codes](/blog/bosch-dishwasher-error-codes)
Next steps
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
