74 Operating the Boiler
10.8 Error Codes
When an error code appears on the front panel, refer to the following chart for a definition and possible remedy for the situation.
Item
Error Code
Description
Reset
Combustion
E001
Overheating of heat exchanger
Manual
E003
Ignition failure
Manual
E004
False flame detection
Auto
E012
Flame loss
Manual
E016
Heat exchanger overheat
Manual
E030
Abnormal exhaust temperature
Manual
E031
Overheating of Burner
Manual
E046
Abnormal operation: Heat exchanger overheating sensor
Auto
E047
Abnormal operation: Exhaust thermostat
Manual/Auto
E060
Abnormal operation: Dual venturi limit switch
Alarm
Air Circulation
E109
Abnormal operation: Fan
Manual
E110
Exhaust blockage (Condensate blockage)
Manual
E127
Abnormal operation: APS
Auto/Manual
Central Heating
Circulation
E205
Heating supply thermistor open or short circuit
Auto
E218
Heating return thermistor open or short circuit
Alarm
E291
Supply/Return inversion limit
Manual Reset
Water Supply
E792
Abnormal operation: DHW circulation
Alarm
E302
Low water pressure
Auto
E352
High water pressure
Auto
E353
Abnormal operation: Water pressure sensor
Auto
DHW Circulation
E407
DHW Outlet thermistor Open or Short Circuit
Alarm
E421
DHW Inlet thermistor Open or Short Circuit
Auto
E434
Abnormal operation: Flow control value
Alarm
E441
DHW Outlet 2 thermistor open or short circuit
Alarm
E445
Abnormal operation: Mixing valve
Alarm
E480
DHW tank thermistor open or short circuit
Alarm
Controller (PCB)
E515
Abnormal operation: Relay feedback (PCB)
Manual
E517
Abnormal operation: DIP switch setting (PCB)
Manual
E593
Abnormal operation: Touch IC (Panel PCB)
Alarm
E594
Abnormal operation: EEPROM (PCB)
Alarm/Manual
E598
Abnormal operation: Panel real time clock
Alarm
Controller (MCU)
E615
Abnormal operation: Input and memory (MCU)
Manual
Installation
E740
Abnormal operation: Outdoor temperature sensor
Auto
E782
Abnormal operation: Main panel communication
Auto
E783
Abnormal operation: OpenTherm remote control
Auto
E787
Abnormal operation: Reset device
Manual/Power Reset
E788
Abnormal operation: Gas type settings
Manual
E792
Abnormal operation: DHW circulation
Alarm
If the error code is not cleared by resetting the boiler functioning (see “10.5 Resetting the Boiler”) 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.