What 8 Means
A value of 8 in the service test programme of an older Bosch dishwasher is the NTC temperature sensor fault. The same manual's full-text display equivalent describes it as short-circuited or open-circuited, which are the two ways a temperature sensor normally fails. Without it the machine cannot judge water temperature, so heating and cycle timing both become unreliable.
Common Causes of 8
- NTC sensor open circuit
- NTC sensor shorted
- Sensor wiring or connector failed
🔧 One Safe Check You Can Try
There is no safe home test, since an NTC is checked by measuring resistance on a de-energised machine. What is useful to note is whether cycles have been running long, ending early, or washing in water that never gets hot.
⚠ Why You Shouldn't Go Further Than That
- The sensor shares its wiring loom with the heating circuit, so disturbing one while testing the other introduces a second fault.
- Because the test-programme numbers add together, an 8 on the display may be accompanied by a heating fault that also needs addressing.
- The sensor sits in the water path near the flow-through heater, which is live during a cycle.
- On machines of this age the connector pins corrode, and a sensor replaced without cleaning them behaves the same way.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.