| ZHE(W) | 0000 | Control module has internal errors. |
| ZHE(W) | 0100 | No start-Safety timeout |
| ZHE(W) | 0104 | Too many attempts at starting |
| ZHE(W) | 0200 | Flame-out during operation |
| ZHE(W) | 0301 | Overvoltage shutoff |
| ZHE(W) | 0302 | Undervoltage shutoff |
| ZHE(W) | 0400 | Flame sensor signals flame before fuel. |
| ZHE(W) | 0403 | Flame does not go out in after-running. |
| ZHE(W) | 0404 | Flame did not go out 3 times in succession in after-running. |
| ZHE(W) | 0601 | Temperature sensor at heat exchanger has Short circuit to ground. |
| ZHE(W) | 0602 | Temperature sensor at heat exchanger has Open circuit or Short circuit to positive. |
| ZHE(W) | 0701 | Solenoid valve for fuel supply has Short circuit to positive. |
| ZHE(W) | 0702 | Solenoid valve for fuel supply has Open circuit or Short circuit to ground. |
| ZHE(W) | 0803 | Burner motor does not rotate. |
| ZHE(W) | 0901 | Ignition spark generator has Short circuit to ground. |
| ZHE(W) | 0902 | Ignition spark generator has Open circuit or Short circuit to positive. |
| ZHE(W) | 1000 | Overheating of auxiliary heater |
| ZHE(W) | 1004 | Too many instances of successive overheating |
| ZHE(W) | 1103 | Water pump has Open circuit. |
| ZHE(W) | 1301 | Overheating sensor has Short circuit to ground or Short circuit to positive. |
| ZHE(W) | 1302 | Overheating sensor has Open circuit. |
| ZHE(W) | 1303 | Temperature difference between temperature sensor and overheating sensor is too large. |
| ZHE(W) | 1401 | Water pump relay has Short circuit to ground or Short circuit to positive. |
| ZHE(W) | 1402 | Water pump relay has Open circuit. |
| ZHE(W) | 1601 | Vehicle blower actuation has Short circuit to ground. |
| ZHE(W) | 1602 | Vehicle blower actuation has Open circuit or Short circuit to positive. |
| ZHE(W) | 1801 | Diagnostic output has Short circuit to positive. |
| ZHE(W) | 2001 | Relay of nozzle preheater has Short circuit to positive. |
| ZHE(W) | 2002 | Relay of nozzle preheater has Open circuit or Short circuit to ground. |
| ZHE(W) | 2101 | Flame display has Short circuit to ground. |
| ZHE(W) | 2102 | Flame display has Open circuit or Short circuit to positive. |
| ZHE(W) | 2201 | Fault display has Short circuit to positive. |
| ZHE(W) | 2202 | Fault display has Open circuit or Short circuit to ground. |