281 Issue 1 - Service Manual - BX3
17
Nine flash
(200mS flashcode:
Flame Lockout
- Invalid Flame A/D valve.
101010101010101010000000)
Flame sense hardware fault.
Ten flash
(200mS flashcode:
False Flame
101010101010101010100000)
Invalid flame sensed during safe start check or IDLE -
hardware fault.
Eleven Flash
SafeStart Lockout
- Secondary safeguard timing fault.
(200mS flashcode:
Main valve safeguard too slow or failed to activate-
101010101010101010101000)
hardware fault.
Twelve flash
SafeStart Lockout
- Secondary safeguard timing fault.
(200mS flashcode:
Safestart checks did not complete in time, no hardware
101010101010101010101010)
fault recorded.
3 Slow flashes
Ground Fault Lockout
- Flame sense fault.
(200mS flashcode:
Flame variation detected due to poor earth connection to
1111100111100111100000000) chassis ground.
A lockout is a result of a detected fault condition, caused by an operational or a safeguard fault.
In the case of a lockout, the unit shall both de-energise the triac drive and stop the control signal
to the relay drive circuit. Consequently the gas valve is completely isolated and will close. The
unit shall remain in lockout until manually reset.
The lockout failure mode shall be distinguished by the status LED flash-code.
Each individual flash shall have a 200milli-second sub-period.
The sequence shall repeat with an approx five –second period.
Lockout shall be cleared by any of the following:
•
Power isolation for more than 2 seconds
•
Cycle of the Thermostat input 6 times within a 60 seconds, each cycle must be at least 2-
seconds in duration.
