Installation Instructions

Owner's Guide
Page
51
Troubleshooting
Display
Green
LED
Malfunction
Description
Diagnosis
391
Two
Times
Air-Fuel ratio rad
failure
• Check for connection/breakage of wires (Part #708)
and/or soot on the AFR rod (Part #108).
510
Six Times
Abnormal main gas
solenoid valve
• Check for connection/breakage of wires (Part #707)
and/or burn marks on the computer board (Part #701).
• Check for signs of vent corrosion.
• Check gas valve contacts and gas valve wire harness
connections for signs of rust or corrosion.
551
Six Times
Abnormal gas
solenoid valve
• Check for connection/breakage of wires (Part #707)
and/or burn marks on the computer board (Part #701).
• Check gas valve contacts and gas valve wire harness
connections for signs of rust or corrosion.
611
Four
Times
Fan motor fault
• Check for connection/breakage of wires, dust buildup
in the fan motor (Part #103) and/or burn marks on the
computer board (Part #701).
• Check for frozen/corrosion of connectors (Part #103).
701
One Time
Computer board
fault
• Check for connection/breakage of wires (Part #711).
711
One Time
Gas solenoid valve
drive circuit failure
• Refer to the 111 and 121 error codes.
721
Six Times
False ame
detection
• Check if there is a leaking from heat exchanger (Part
#401).
751
N/A
Miscommunication
between micro-boiler
and temperature
controller
• Inspect the connections between the micro-boiler and
temperature controller.
• Check the power supply of the micro-boiler.
941
Five
Times
Abnormal exhaust
temperature
• Check to see if the exhaust temperature is higher than
149°F (65°C).
991
Five
Times
Imperfect
combustion
• Check if the gas type of the micro-boiler matches the
gas supplied to it.
• Inspect the environment around the micro-boiler.
Determine how long the micro-boiler has been installed
and match DIPswitches.
• Check the altitude/elevation of the area of where the
micro-boiler is installed.
• Check if there is any blockage in the intake air and/or
exhaust.
• If the micro-boiler is installed as a direct-vent system,
check whether there is enough distance between the
intake air terminal and the exhaust terminal.
• Check if there is grease and/or dirt in the burner (Part
#101) and the fan motor (Part #103), especially if the
micro-boiler has been installed in a contaminated area.
• Check the DIPswitches match gas type of the micro-
boiler.
• Check the manifold pressure at Max. and Min.
• Check combustion chamber tube (Part #117) to see if it
is clear and securely installed.