Neither the Vallox Modbus manual nor the unit's own web UI resolve fault
codes to descriptive text — the unit's own fault log (both the web UI and,
per the manual, the physical control panel) shows only the bare numeric
code, severity, dates, and occurrence count. There is no general-purpose
code-to-text lookup built into the product for most codes.
These entries are reverse-engineered from literal strings found in the
unit's firmware (HSWUPD.BIN, panel-text data block), each confirmed to
sit alongside genuine error/alert UI strings (e.g. "Error message"),
rather than being generic catalog entries — they correspond to a handful
of specific, common/critical alert conditions that get dedicated banner
text elsewhere in the UI, not a per-code description table. Codes 3 and 9
are included with lower confidence: the exact wording was found in the
firmware, but in a section related to CFI airflow-sensor diagnostics
rather than clearly alongside the other alert strings, so it's plausible
but unconfirmed that this is really what shows for that fault code.
All other codes — including ones known to be real and reachable in current
firmware (13–22 and 24, from a "Tornado" post-heater subsystem) — have no
recoverable description from any source checked (official manuals current
and historical, the web UI, community integrations, or the firmware
itself) and correctly resolve to 'Unknown fault'.
Fault code to description mapping.
Neither the Vallox Modbus manual nor the unit's own web UI resolve fault codes to descriptive text — the unit's own fault log (both the web UI and, per the manual, the physical control panel) shows only the bare numeric code, severity, dates, and occurrence count. There is no general-purpose code-to-text lookup built into the product for most codes.
These entries are reverse-engineered from literal strings found in the unit's firmware (
HSWUPD.BIN, panel-text data block), each confirmed to sit alongside genuine error/alert UI strings (e.g. "Error message"), rather than being generic catalog entries — they correspond to a handful of specific, common/critical alert conditions that get dedicated banner text elsewhere in the UI, not a per-code description table. Codes 3 and 9 are included with lower confidence: the exact wording was found in the firmware, but in a section related to CFI airflow-sensor diagnostics rather than clearly alongside the other alert strings, so it's plausible but unconfirmed that this is really what shows for that fault code.All other codes — including ones known to be real and reachable in current firmware (13–22 and 24, from a "Tornado" post-heater subsystem) — have no recoverable description from any source checked (official manuals current and historical, the web UI, community integrations, or the firmware itself) and correctly resolve to 'Unknown fault'.