The E13 error on your Bosch Dishwasher means the appliance has detected a fault with its flow heater or water temperature sensor. This usually stops the wash cycle partway through to protect the heating element from damage. In most cases the issue can be traced to a wiring fault, a failed sensor, or limescale buildup around the heating coil.
| Error code | E13 |
|---|---|
| Meaning | Flow heater / temperature sensor (NTC) circuit fault detected during the wash cycle |
| Severity | Medium — the dishwasher will not heat water properly until resolved |
| Time to fix | 20–45 minutes |
| Tools needed | Multimeter, screwdriver set, descaler (optional) |
What the E13 error means
E13 is triggered when the dishwasher's control board cannot get a consistent or valid reading from the flow-through heater's temperature sensor. Because Bosch dishwashers rely on precise water temperature control for both washing and drying, the machine halts the cycle rather than risk overheating or under-heating the water. This is similar to how electrical safety cut-outs work on other Bosch appliances and tools — for example, a wiring fault is also a common reason a Bosch Drill Won'T Start: Causes and How to Fix It, since both rely on uninterrupted electrical continuity to function safely.
Common causes
- Limescale or mineral buildup coating the flow heater element
- A failed or drifting NTC temperature sensor
- Loose or corroded wiring connectors near the heater assembly
- A faulty main control board misreading sensor signals
- Low water flow caused by a clogged filter or spray arm restricting heat exchange
- Old age wear on internal components after years of hard water use
How to fix the E13 error
- Power cycle the dishwasher. Turn it off at the wall, wait two minutes, then restart to see if the code clears — this resets minor sensor glitches.
- Check and clean the filters. Remove and rinse the lower filter assembly and spray arms to restore proper water flow to the heater.
- Descale the machine. Run a dishwasher-safe descaling product through a hot empty cycle to remove limescale from the flow heater.
- Inspect wiring connections. With the machine unplugged, open the lower service panel and check that the heater and sensor connectors are firmly seated and free of corrosion, much like checking terminals when a Bosch Drill Battery Not Connecting: Causes and How to Fix It — loose contacts are often the root cause in both cases.
- Test the NTC sensor with a multimeter. Compare resistance readings against Bosch's specification; a sensor well outside range needs replacing.
- Call a qualified technician. If the fault persists after these checks, the control board or heating element itself may need professional replacement.
FAQ
Can I still run a wash cycle with the E13 error showing?
It's best not to. The dishwasher may run a cold cycle, but dishes won't be sanitised properly and running it repeatedly can strain the control board.
Is E13 covered under Bosch warranty?
If your dishwasher is still within its warranty period and the fault isn't caused by misuse or limescale neglect, it's often covered — check with Bosch support or your retailer.
Will descaling always fix E13?
Not always, but it resolves a large share of cases caused by hard water areas. If descaling doesn't clear the code, the sensor or wiring is the next likely cause.
