The E446 error on your Bosch Dishwasher means the appliance has detected a problem with the water heating circuit or the flow of water through the system, and it cannot verify that water is heating or circulating correctly. This usually stops a wash cycle partway through. A few simple checks often resolve it before you need to call an engineer.
| Error code | E446 |
|---|---|
| Meaning | Water heating or flow sensor fault detected during a wash cycle |
| Severity | Medium — the dishwasher will usually pause or stop the cycle to protect itself |
| Time to fix | 15–45 minutes |
| Tools needed | Multimeter, screwdriver, torch |
What the E446 error means
Bosch dishwashers use sensors to monitor water temperature and flow as part of every wash cycle. When the control board doesn't receive the expected reading within a set time, it triggers the E446 code as a safety measure. This can be caused by a genuine heating fault, a blocked water path, or simply a loose wiring connection that's interrupting the signal.
In most cases the error is not permanent damage — it's the machine reporting that something in the heating or flow chain isn't behaving as expected, so it stops rather than risk running an incomplete or unsafe cycle.
Common causes
- Limescale or debris build-up on the heating element reducing efficiency
- Blocked or kinked water inlet hose restricting flow
- Faulty flow sensor or temperature sensor giving incorrect readings
- Loose or corroded wiring connector at the heater or sensor
- Clogged filter at the base of the dishwasher affecting water circulation
- Failing control board unable to process sensor signals correctly
How to fix the E446 error
- Power down and reset: Turn off the dishwasher at the wall, wait two minutes, then switch it back on. This clears minor sensor glitches and lets the system re-check itself.
- Check the water supply: Make sure the inlet hose isn't kinked, the tap is fully open, and water pressure is normal. Low or no water flow is a common trigger for this code.
- Clean the filters: Remove and rinse the lower filter assembly under the sprayer arms. A blocked filter restricts water flow and can mimic a heating fault.
- Inspect wiring connections: With the dishwasher unplugged, open the lower panel and check the connectors on the heating element and flow sensor for looseness or corrosion. Reseat any loose plugs.
- Test the heating element: Using a multimeter, check the element for continuity. If there's no reading, the element has likely failed and needs replacing.
- Call a qualified engineer: If the error persists after these checks, the control board or sensor itself may need professional diagnosis and replacement.
FAQ
Can I still use my dishwasher if it shows E446?
It's best to stop the cycle and address the fault first, since running it repeatedly can strain the heating element or motor further.
Is E446 dangerous?
No, it's a protective error code, not a safety hazard. The dishwasher stops itself rather than continuing an unsafe or ineffective cycle.
Will resetting the dishwasher always fix E446?
Not always — a reset clears temporary glitches, but if the cause is a blocked filter, faulty sensor, or worn heating element, the error will return until that part is fixed or replaced.
