Bosch Dishwasher Error Code E03
Bosch lists E03 as a relay fault on the main control board, in the same family as E01 and E02. On some model lines the same code shows when the dishwasher cannot fill with water, so it is worth confirming the tap and supply first. If the machine fills normally and the code still appears, the board itself is the likely problem.
Also shown as: E3
Common causes
- Failed auxiliary heater relay on the control board
- Faulty water inlet valve (some models)
- Closed or weak water supply (some models)
- Control board failure
What to check, in order
- Make sure the supply tap is fully open and the inlet hose is not kinked.
- Reset power at the breaker for 30 seconds and start a cycle, listening for water entering.
- If the machine fills but E03 returns, stop and book a service visit for the control board.
Clear the code and test
- Fix what the checks above found first — a filter cleaned, a hose straightened, the spray arms freed. Clearing the code without fixing the cause only brings it back.
- Close the door, plug the dishwasher back in (or restore its breaker) and make sure the water tap is open.
- Run the shortest programme and stay nearby for the first minutes, watching for leaks and listening for the drain pump.
- If the programme finishes with no code, the fault is cleared. If the code returns, write down the code and when it appeared before calling a technician — it speeds up the diagnosis.
When to call a professional
This code usually points to a faulty part, wiring or the control board on a Bosch dishwasher. Run the checks above to rule out the simple causes, then book a technician — and book one straight away if any of these apply:
- The code comes back after you have run the checks and a test cycle.
- You smell burning, see sparks or scorch marks, or the breaker trips.
- Water is leaking and you cannot stop it at the tap.
- The fix needs panels opened beyond what your manual describes, or a part tested with a meter, and you are not set up for that.
When you call, give the brand, the code E03, your model number (on a label inside the door or on the back) and the checks you already ran. It shortens the visit.
Repair or replace?
This fault is in professional territory: the fix usually means a major part or board-level work, and the labour adds up. If your machine is already well into its service life, get the repair quote first, then compare it with the price of a current equivalent model before you decide. Paying a large share of a new machine's price to repair an old one is rarely the better deal; replacing a machine over one cheap fault is wasteful too.
Parts that may be involved
Main control boardWater inlet valveInlet hose
Parts are model-specific. Find your model number first — usually on a label inside the door, on the door frame or on the back — and match the part to that number before ordering.
Questions people ask about E03
What does E03 mean on a Bosch dishwasher?
E03 means: Control board relay fault; on some models the machine cannot fill. Bosch lists E03 as a relay fault on the main control board, in the same family as E01 and E02. On some model lines the same code shows when the dishwasher cannot fill with water, so it is worth confirming the tap and supply first. If the machine fills normally and the code still appears, the board itself is the likely problem.
Can I fix Bosch E03 myself?
Only the preliminary checks. Code E03 usually means a part, wiring or the control board has failed, which is a technician job. Run the checks to rule out simple causes before you book.
How do I clear Bosch E03?
Fix the cause first — clearing the code on its own brings it straight back. Then restore power and water, run the shortest programme, and watch the stage where the code appeared. If the programme finishes with no code, it is cleared.
Sources checked
- Bosch Home (US) owner support: dishwasher error codes
- Coolblue advice: Bosch and Siemens washing machine errors
The meaning and checks for this code were checked against the sources above in November 2026. Codes vary by model and region; if your manual lists a different meaning for your exact model, follow the manual.