The E230 error on your Bosch Dishwasher means the appliance has detected a problem with its water temperature sensor (thermistor) or the heating circuit isn't reaching the expected reading during a wash cycle. In most cases this is fixable at home by checking the sensor wiring and connections before calling an engineer.
| Error code | E230 |
|---|---|
| Meaning | Water temperature sensor fault or heating circuit not registering correctly |
| Severity | Medium — dishwasher may still run but with poor wash/dry results |
| Time to fix | 15–45 minutes |
| Tools needed | Multimeter, screwdriver set |
What the E230 error means
Bosch dishwashers use a temperature sensor (thermistor) to monitor water temperature throughout the wash cycle, telling the control board when to activate or deactivate the heating element. When this code appears, the control board isn't receiving a valid signal from the sensor, or the heater isn't responding as expected. This can cause cycles to run cold, take longer than normal, or stop partway through.
The fault can be caused by a genuinely broken sensor, a loose connector, or a wiring issue between the sensor and the main control board. It's rarely something you need to replace the whole machine for, but it does need checking properly since a faulty sensor can leave dishes unwashed or unsanitised.
Common causes
- Temperature sensor (thermistor) has failed or given an out-of-range reading
- Loose or corroded wiring connector at the sensor or control board
- Limescale or debris buildup around the sensor affecting its accuracy
- Heating element fault causing the sensor to report inconsistent temperatures
- Control board fault misreading a correctly working sensor
- Recent power surge or electrical fault that disrupted the sensor circuit
How to fix the E230 error
- Power cycle the dishwasher. Turn off at the wall, wait 2–3 minutes, then switch back on. This resets the control board and can clear a temporary sensor glitch.
- Check for standing error codes. Run a short cycle and watch if E230 reappears immediately or only under certain conditions, which helps narrow down whether it's a wiring fault or sensor failure.
- Inspect the sensor and wiring. Remove the lower access panel with a screwdriver and check the temperature sensor connector for corrosion, looseness, or damage. Reseat the connector firmly.
- Test the sensor with a multimeter. Check the resistance reading against Bosch's specification for your model (usually found in the service manual). A reading well outside range confirms the sensor needs replacing.
- Clean around the sensor. Limescale buildup can interfere with readings — run a descaling cycle or wipe the sensor area with a vinegar solution if accessible.
- Replace the faulty part. If the sensor tests bad, order the correct part number for your model and swap it, following the wiring diagram carefully. If issues persist after replacement, the control board itself may need professional diagnosis.
FAQ
Can I keep using the dishwasher with an E230 error showing?
You can run cycles, but expect poor washing or drying results since water temperature isn't being controlled properly. It's best to fix it soon rather than run repeated cycles.
Is the E230 fault expensive to repair?
A replacement temperature sensor is usually a low-cost part, often under £30/$40. Labour costs more if you're not comfortable doing it yourself, but the part itself is inexpensive.
Do I need a multimeter to diagnose this at home?
Not strictly, but it makes the difference between guessing and confirming the sensor is faulty. If you don't have one, a basic multimeter is a low-cost, useful tool to have for household appliance checks — similar to the way homeowners keep a reliable screwdriver set or drill on hand for repairs.
