Fireye NX6300 (Nexus) troubleshooting
The Fireye NX6300 is a single-fuel integrated burner control in the Nexus range. Its fault numbers carry a letter prefix that tells you whether the fault is still present, has cleared, or is a limit, and it keeps a long event history, so the history is usually more useful than the single fault on screen.
Diagnose this with AI
Try Free Boiler Diagnostic Upload a photo of the alarm screen, the fault history or a data export. InduQT compares the evidence and suggests the next useful checks.
How it reports faults
- Each fault number has a prefix: F means the fault occurred and is still present, C means it occurred and has cleared, L means a programmed limit was exceeded.
- Some faults and limits only raise a warning rather than a lockout.
- Fault subsets are bit-sum codes (1, 2, 4 … 128) read on the Engineer’s Key screen, for example C10 with subset 16.
- The display stores the last 128 events and faults with status data, kept through power loss. View them via the Engineer’s Key screen (F4 LOG), the touchscreen Menu > Fault/Event Log, or ComFire2 software.
Fault codes
| Code | Name |
|---|---|
| F10 | Flame Failure: no flame seen when one should be present |
| F11 | False Flame: flame seen when none should be present |
| F66 | Flame Test: dark test failed |
Evidence to collect
- Photo of the fault with its F/C/L prefix and subset
- The event log around the lockout
- Burner status at the time (from the subset)
- Flame scanner type and signal
Work on fuel trains, burners, pressure vessels and electrical equipment must be done by qualified personnel following the manufacturer’s documentation and local codes. Never bypass a safety device or interlock.