| 003 | Navien Tankless Water Heater Error Code 003: How to Fix Flame Failure | high | Medium |
| 004 | Navien Tankless Water Heater Error Code 004: How to Fix It | medium | Medium |
| 005 | Navien Water Heater Error Code 005: How to Fix It | high | Medium |
| 006 | Navien Water Heater Error Code 006: How to Fix It | high | Medium |
| 007 | Navien Water Heater Error Code 007: How to Fix It | medium | Medium |
| 008 | Navien Water Heater Error Code 008: How to Fix It | medium | Medium |
| 009 | Navien Tankless Water Heater Error Code 009: How to Fix It | medium | Medium |
| 010 | Navien Tankless Water Heater Error Code 010: How to Fix It | medium | Medium |
| 012 | Navien Tankless Water Heater Error Code 012: How to Fix It | medium | Medium |
| 014 | Navien Water Heater Error Code 014: How to Fix It | medium | Medium |
| 016 | Navien Water Heater Error Code 016: How to Fix It | medium | Medium |
| 017 | Navien Water Heater Error Code 017: How to Fix It | medium | Medium |
| 020 | Navien Water Heater Error Code 020: How to Fix Low Inlet Water Flow | medium | Medium |
| 022 | Navien Water Heater Error Code 022: How to Fix It | medium | Medium |
| 024 | Navien Water Heater Error Code 024: How to Fix It | medium | Medium |
| 027 | Navien Water Heater Error Code 027: How to Fix It | medium | Medium |
| 029 | Navien Tankless Water Heater Error Code 029: How to Fix It | medium | Medium |
| 030 | Navien Water Heater Error Code 030: How to Fix It | medium | Medium |
| 031 | Navien Water Heater Error Code 031: How to Fix It | medium | Medium |
| 032 | Navien Water Heater Error Code 032: How to Fix It | medium | Medium |
| 038 | Navien Water Heater Error Code 038: How to Fix It | medium | Medium |
| 039 | Navien Water Heater Error Code 039: How to Fix It | medium | Medium |
| 040 | Navien Tankless Water Heater Error Code 040: How to Fix It | high | Easy |
| 047 | Navien Tankless Water Heater Error Code 047: How to Fix It | medium | Medium |
| 048 | Navien Tankless Water Heater Error Code 048: How to Fix It | medium | Medium |
| 050 | Navien Tankless Water Heater Error Code 050: How to Fix It | medium | Easy |
| 060 | Navien Tankless Water Heater Error Code 060: How to Fix It | medium | Medium |
| 080 | Navien Water Heater Error Code 080: How to Fix It | medium | Medium |
| 099 | Navien Water Heater Error Code 099: How to Fix It | high | Medium |
| 11 | Navien Water Heater Error Code 11: How to Fix It | critical | Medium |
| 110 | Navien Water Heater Error Code 110: How to Fix It | high | Medium |
| 12 | Navien Water Heater Error Code 12: How to Fix It | critical | Medium |
| 16 | Navien Water Heater Error Code 16: How to Fix It | critical | Medium |
| 27 | Navien Water Heater Error Code 27: How to Fix It | high | Medium |
| 28 | Navien Water Heater Error Code 28: How to Fix It | high | Medium |
| 30 | Navien Water Heater Error Code 30: How to Fix It | high | Medium |
| 303 | Navien Tankless Water Heater Error Code 303: How to Fix It | medium | Medium |
| 304 | Navien Tankless Water Heater Error Code 304: How to Fix It | medium | Medium |
| 311 | Navien Water Heater Error Code 311: How to Fix It | high | Medium |
| 351 | Navien Water Heater Error Code 351: How to Fix It | high | Medium |
| 38 | Navien Water Heater Error Code 38: How to Fix It | high | Hard |
| 43 | Navien Water Heater Error Code 43: How to Fix It | high | Hard |
| 432 | Navien Water Heater Error Code 432: How to Fix It | medium | Medium |
| 434 | Navien Tankless Water Heater Error Code 434: How to Fix It | medium | Medium |
| 438 | Navien Water Heater Error Code 438: How to Fix It | medium | Medium |
| 442 | Navien Water Heater Error Code 442: How to Fix It | medium | Medium |
| 47 | Navien Water Heater Error Code 47: How to Fix It | medium | Medium |
| 515 | Navien Water Heater Error Code 515: How to Fix It | critical | Hard |
| 60 | Navien Water Heater Error Code 60: How to Fix It | medium | Medium |