The E455 error on your Bosch Dishwasher means the appliance has detected a communication fault between the main control board and one of the internal components, often related to the water flow or heating system. This code usually needs a diagnostic check rather than a quick reset, so it's worth working through some basic troubleshooting before calling an engineer.
| Error code | E455 |
|---|---|
| Meaning | Communication or signal fault between the control board and a connected sensor/module |
| Severity | Medium — the dishwasher may still run but cycles could be interrupted or incomplete |
| Time to fix | 15–45 minutes |
| Tools needed | Multimeter (optional), screwdriver |
What the E455 error means
Bosch dishwashers use a network of sensors and modules that constantly send signals back to the main control board. When one of these signals is interrupted, delayed, or unreadable, the E455 code appears as a warning that something in this chain isn't working correctly. This is often linked to wiring, connector corrosion, or a failing sensor rather than a fault with the entire control board itself.
Common causes
- Loose or corroded wiring connectors inside the base of the dishwasher
- A faulty flow meter or water level sensor sending inconsistent signals
- Recent power surge or voltage fluctuation disrupting the control board
- Moisture ingress affecting a sensor connection point
- A firmware glitch after a power cut or reset
- Ageing or worn wiring harness due to normal use over several years
How to fix the E455 error
- Power cycle the dishwasher: Turn off at the wall, wait two minutes, then switch back on. This clears temporary communication errors and is worth trying first.
- Check the door is fully closed and latched: A door that isn't sealing properly can sometimes trigger sensor faults that show up as unrelated error codes.
- Inspect accessible wiring connections: With the power off, check any visible connectors near the base panel for looseness, corrosion, or moisture damage.
- Run a short test cycle: After resetting, run a quick wash cycle to see if the error returns. If it clears, the issue may have been a one-off glitch.
- Check for a firmware update: Some newer Bosch models allow a diagnostic reset via the service menu — check your model's manual for instructions.
- Book a professional repair if the code persists: If E455 keeps returning after these steps, the flow meter, wiring harness, or control board itself likely needs inspection or replacement by a qualified technician.
FAQ
Can I keep using my dishwasher if it shows E455?
You can usually still run cycles, but performance may be inconsistent. It's best to address the fault soon to avoid further strain on the control board.
Will resetting the power always fix E455?
Not always. A power cycle resolves temporary glitches, but if the fault is caused by damaged wiring or a failing sensor, the code will return until that part is repaired.
Is this error expensive to fix?
It depends on the cause. A loose connector costs nothing to fix yourself, while a replacement flow meter or control board will involve parts and labour costs from a technician.
