281 Issue 1 - Service Manual - BX3
22
5.10 Nine Flashes - Flame Lockout Invalid Flame
Reason
•
Flame sense hardware fault.
•
Control board start up safety check failure.
Service Checklist
1. Check power supply.
2. Check polarity at power point.
3. Check transformer voltage.
4. Check flame sensor.
5. Hardware fault during start up operation.
5.11 Ten Flashes – False Flame
Reason
•
Invalid flame sensed during safe start check or IDLE – hardware fault.
Detection of flame signal at power-up, while IDLE, or prior to ignition shall cause the unit to enter
a volatile lockout and flash ten times on the status LED. Detection of the flame signal variation
indicative of a grounding fault shall cause the unit to enter a volatile lockout.
Service Checklist
1. Check power supply.
2. Check polarity at power point.
3. Check transformer voltage.
4. Check over heat switch is faulty.
5. Gas valve passing gas.
5.12 Eleven Flashes - SafeStart Lockout
Reason
•
Main valve safeguard too slow or failed to activate – hardware fault.
Confirmation that the secondary safeguard hardware timing circuit is within tolerance.
Measurements are made by the micro-controller concerning the ability of the flame circuit to
operate the secondary safeguard circuit, and that the timing is within allowable tolerance. The
upper limit is the specified flame establishment time. If the safeguard circuit fails verification, the
unit shall enter lockout and shall flash eleven flashes on the status LED.
Service Checklist
1. Check power supply.
2. Check polarity at power point.
3. Check transformer voltage.
4. Control board failure.
5.13 Twelve Flashes – Secondary Fafeguard Timing Fault
