E0103 explained
E0103 tells you the dishwasher has found a relay fault or error on its main control board. Relays are the switches the board uses to power the big loads: the pump, the heater, the drain pump and the water valve. When one sticks or fails to switch, the dishwasher can no longer run its programme safely. A restart is worth a try, but a returning E0103 means the board, or what it switches, needs testing.
Error codes
Reference| Code | Meaning |
|---|---|
| E0103 | There is a main control board relay fault/error. |
What E0103 can look like
- A part runs when it should not — For example, the drain pump running continuously or water filling at the wrong time.
- A part never switches on — No heating, no draining or no filling at the stage where it should happen.
- Clicking from the door or base area — The board's relays switching repeatedly without effect.
- The programme stops with E0103 — The board halts the cycle once it detects the fault.
Likely causes, ranked
- A worn or welded relay on the board — First: relays switch heavy loads many times every cycle, and their contacts wear or stick over the years.
- A load drawing too much current — Second: a heater or pump with an internal short can damage the relay that switches it.
- Moisture on the control board — Third: water or steam reaching the board can disturb the relay circuits.
- A supply disturbance — Fourth: a power cut or surge mid-cycle can leave the board reporting an error that a restart clears.
Order of checks
- Restart the dishwasher — Breaker off for a few minutes, then a short programme.
- Note which part misbehaves — Draining, heating or filling at the wrong time tells a professional which relay to test.
- Check for leaks or water in the base — Water reaching the electronics or a load can cause relay faults.
- Note any burning smell — That calls for leaving the dishwasher off.
What you can do
- Restart from the breaker — Switch off, wait a few minutes, restore power.
About 5 min
- Run a short programme and watch — Note when the code appears and what the dishwasher was doing.
Tools: notepadAbout 30 min
- Check under the front for water — With the power off, look around the base and floor with a torch.
Tools: flashlightAbout 5 min
- Cut the power if the drain pump runs non-stop — Switch off at the breaker and leave it off.
Tools: ::
- Stop at the electronics — The control board and the loads it switches are tested behind panels with the power isolated.
Tools: ::
Electrical safety
Safety
Relay faults can leave a part powered when it should be off, so switch off the dishwasher at its breaker if anything runs continuously. Do not open the door panel or the toe panel looking for the board: it can hold a charge after the power is removed and sits close to mains wiring. Wipe up any water on the floor before standing near the dishwasher.
When E0103 needs a professional
Get help when E0103 returns after a restart, when a part runs continuously or never switches on, or when there is a burning smell. A professional tests the relays and the loads they switch, because replacing a board without finding a shorted heater or pump can lead to the new board failing too.
Neighbouring dishwasher codes
Which dishwashers this covers
This reading covers Bosch built-in dishwashers where the brand lists E0103. It does not cover other Bosch appliances or other brands, which use their own codes. No model-specific E0103 page has been published; board locations and part numbers vary by model, so use the documentation for your model number.
Bosch dishwasher codes
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
