Takagi T-H3M-IN/OS - Manual (Page 47)

47
Page
Remote
Green
LED
Malfunction
description
Diagnosis
391 Two Times Air-fuel ratio rod
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 flame
detection
• Check if there is leaking from heat exchanger (Part #401)
741 N/A Miscommunication
between water
heater and remote
controller
• Check the model type of the remote controller
• Inspect the connections between the water heater
and remote controller
• Check the power supply of the water heater
751 N/A Miscommunication
between water heater
and temperature
controller (Indoor
model only)
• Inspect the connections between the water heater
and temperature controller
• Check the power supply of the water heater
941 Five Times Abnormal exhaust
temperature (Indoor
model only)
• Check to see of the exhaust temperature is higher
than 149°F (65°C)
991 Five Times Imperfect
combustion
• Check if the gas type of the water heater matches
the gas supplied to it
• Inspect the environment around the water heater
Determine how long the water heater has been
installed and match DIPswitches
• Check the altitude/elevation of the area of where
the water heater is installed
• Check if there is any blockage in the intake air and/
or exhaust
• If the water heater 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
water heater has been installed in a contaminated area
• Check the DIPswitches match gas type of the water
heater
• Check the manifold pressure at Max and Min
• Check combustion chamber tube (part #117) to see if it
is clear and securely installed
Troubleshooting
Owner's Guide