Bosch Dishwasher E02 — What It Means & How to Fix It
Also shown as E03 on some models.
A switching relay on the Bosch dishwasher's main control board is not behaving as the electronics expect — Bosch reports this as both E02 and E03 — so try one power reset, then it is a board-level repair.
What this code means
E02, and the closely related E03, tell you a relay on the main control board has faulted. Relays are the small electromechanical switches the board uses to send mains power to parts like the heater, pump, or valves, so a stuck or failed one can stall a cycle in several different ways. Bosch assigns both codes to the same board-relay problem.
Bosch documents E02 and E03 with the identical “control board relay” meaning, so treat them the same; this page covers both. Confirm against your model's manual if the display shows anything beyond the two-character code.
Most likely causes
| Cause | How likely | DIY-fixable? |
|---|---|---|
| A relay on the main control board has stuck or failed | Common | No — technician job |
| Solder joints around a board relay have cracked from heat cycling | Occasional | No — technician job |
| A power surge left the board in a faulted state | Occasional | Yes — power reset only |
| A downstream wiring fault is confusing the relay feedback | Less common | No — technician job |
What you can try yourself
- Cut power at the breaker or unplug the dishwasher, leave it off for two minutes, and switch it back on; a surge-related E02 or E03 often will not return after this.
- Run a short cycle and confirm whether the same code reappears — if E03 shows where E02 did, or the reverse, it is still the same relay fault.
- If it persists, leave the machine off and book a repair, since a faulty board relay carries mains voltage and is replaced as part of the control board.
- Tell the technician which functions stalled — no heat, no drain, or no fill — because that narrows down which relay is involved.
When to call a technician
- E02 or E03 returns after a full power-down, confirming a real relay fault.
- Part of the cycle never starts: no heating, no drain, or no fill at all.
- You hear repeated clicking from the lower front of the machine where the board sits.
Typical professional repair cost: Expect $90–$160 for diagnosis; a control board replacement typically totals $250–$450 with labor.
Frequently asked questions
What is the difference between Bosch E02 and E03?
In Bosch's own documentation both codes describe a main control board relay fault, so there is no practical difference for you and the fix is the same. That is why they share this page.
Can a power surge cause a Bosch E02 error?
Yes. A surge or brownout can leave the board's relays in a faulted state, and a two-minute power-down often clears it. If the code returns after that reset, the relay or board has actually failed.
Is it worth repairing the control board?
On a newer or higher-end Bosch it usually is, since the rest of the machine is sound. On an older unit nearing ten years, weigh the $250–$450 board cost against replacing the dishwasher.
Related Bosch codes
- Bosch Dishwasher E15 Water reached the base pan under the tub and Bosch's leak protection locked the machine — sometimes a genuine leak, often a one-off spill or condensation that clears once the base dries.
- Bosch Dishwasher E24 The dishwasher can't drain properly — start with the filter, then the drain hose path, and don't skip checking that the drain pump cover is seated.
- Bosch Dishwasher E25 The drain pump itself is blocked or its cover is loose — and Bosch makes the pump cover owner-accessible, so this is one of the most fixable codes the brand throws.
- Bosch Dishwasher E09 The heating system isn't raising the water temperature — beyond one reset, the flow-through heater is a mains-voltage part that belongs to a technician.
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