H2 SENSOR ALARM Honeywell — Battery Room Ventilation Failure
At a glance
- Severity
- WARNING THEN STOP
- Domain
- SUPERVISION_SYSTEM
- Reference standard
- EN 50600-2-2 / IEC 62485-2
What it means
Lead-acid battery room ventilation fails: hydrogen accumulation with explosion risk. A silent fault that turns a normal event (charging) into a grave hazard.
Probable causes
- Fan failed or tripped
- Intake dampers closed or stuck
- Fan command not guaranteed (auxiliaries)
- Hydrogen detection absent or out of service
Where to start
Verify fan and damper operation and, if present, the H2 sensor reading. If accumulation is suspected, naturally ventilate before entering.
Full guided diagnosis in the app
The diagnostic tree for this fault has 3 guided steps with measurements, checks and resolutions. You'll find it in DataCIQ, one of the five IndexOS apps: free, works offline.
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The same fault on other brands
More Honeywell codes
- ALARM ROUTING FAULT — Alarms Not Notified
- CONTROLLER OFFLINE — Access Control Offline
- ABORT ACTIVE — Suppression Release Failure
- ALARM VERIFY — False Fire Alarm
- BAT FAIL — Battery Low / Battery Failure
- BAT FAIL — Fire Panel Battery Low
- COMM FAIL — Communication Lost / Controller Offline
- COMM FAIL — Reader Offline / Reader Not Communicating