Troubleshooting 13
4.2 Understanding Error Codes
W
hen an error code appears on the front panel, refer to the following chart for a definition and possible remedy for the situation.
Auto reset
R
eason
Self-diagnostic / Action
E003
Ignition failure
Manual reset
E004
False flame detection
Auto reset
E012
Flame loss
Manual reset
E016
Heat exchanger overheat
Manual reset
E030
Abnormal exhaust temperature
Manual reset
Auto reset
E046
Abnormal operation: heat exchanger overheating sensor
Auto reset
E047
Abnormal operation: exhaust thermostat
Auto reset
E060
Abnormal operation: dual venturi limit switch
Auto reset
E109
Abnormal operation: fan
Manual reset
E110
Exhaust blockage (Condensate blockage)
Manual reset
E127
Abnormal operation: APS
Manual reset
Auto reset
E407
Abnormal operation: hot water outlet1 thermistor
Auto reset
E421
Abnormal operation: cold water inlet1 thermistor
Auto reset
E432
Abnormal operation: cold water inlet2 thermistor
Auto reset
E434
Abnormal operation: water adjustment valve
Manual reset
E438
Abnormal operation: circulation pump
Manual
Auto reset
E439
Abnormal operation: flow sensor
Manual reset
E441
Abnormal operation: hot water outlet2 thermistor
Auto reset
E445
Abnormal operation: mixing valve
Manual reset
E515
Abnormal operation: relay feedback (PCB)
Manual reset
E517
Abnormal operation: dip switch setting (PCB)
Manual reset
E593
Abnormal operation: front panel key
Auto reset
E615
Abnormal operation: input and memory (MCU)
Manual reset
E736
Abnormal operation: cascade communication
Auto reset
E760
Flushing alarm
Alarm
E782
Abnormal operation: main panel communication
Auto reset
E787
Abnormal operation: reset device
Manual reset
Power reset
If the error code is not cleared by resetting the water heater functioning (see
“
3.4 Resetting the
W
ater Heater
”
) or if it occurs repeatedly,
call the nearest official Technical Assistance Service (TAS), indicating the number of the error code appearing on the front panel.
