Vaillant ecoMAX 665 Installation And Maintenance Manual page 35

Code Meaning
F0.0 Interruption supply sensor
F.1 Interruption return sensor
F.10 Short circuit supply sensor
F.11 Short circuit return sensor
F.13 Short circuit cylinder sensor
F.20 Water safety thermostat
F.22 Dry burning (no water in the
appliance)
F.23 Lack of water
Temperature spread too large
System not bled properly
F.24 Lack of water
Temperature rise too fast
System not bled correctly
F.25 Flue safety thermostat flue tempera-
ture too high, system pressure too low
F.27 Flame simulation (flame signal despite
gas valve being switched off)
F.28 No ignition when starting
F.29 No reignition
F.32 Speed deviation fan
(too large when starting)
F.37 Speed deviation fan
(too high or too low during operation)
F.42 Short circuit coding resistance
F.43 Interruption coding resistance
F.60 Gas valve control
"+" faulty
F.61 Gas valve control
"-" faulty
F.62 Gas valve shut-off faulty
F.63 EEPROM faulty
F.64 Electronics/sensor fault
F.65 Electronics temperature too high
F.67 Electronics error flame
(implausible flame signal)
Emergency Special message:
run no speed signal from the fan
"speed"
Table 8.3: Error codes
Installation and maintenance manual ecoMAX 665 / 0020020159_03
Cause
NTC connector not plugged in or loose,
NTC defective,
multi-plug on the electronics not plugged in properly
NTC connector not plugged in or loose,
NTC defective,
multi-plug on the electronics not plugged in properly
NTC defective,
short-circuit to ground/short circuit in the cable harness
NTC defective,
short-circuit to ground/short circuit in the cable harness
NTC defective,
short-circuit to ground/short circuit in the cable harness,
inside of the plug damp
supply or return NTC defective (intermittent contact),
supply temperature too high,
the appliance not correct,
failed discharge to the electrode via ignition cable, ignition plug or ignition
electrode
no water in the primary heat exchanger when commissioning,
RESET activated when appliance is hot,
water pressure switch has been triggered, flow switch has been triggered
pump jammed, reduced output of the pump,
air in the appliance, system pressure too low,
supply and return NTC mixed up,
appliance not filled via appliance-internal KFE cock (fill only via return!),
start venting program
pump jammed, reduced output of the pump,
air in the appliance, system pressure too low,
supply and return NTC mixed up,
appliance not filled via appliance-internal KFE cock (fill only via return!),
start venting program
plug connector option flue gas thermostat interrupted,
water pressure switch has been triggered, flow switch has been triggered
gas solenoid valve leaking,
electronics (flame detector defective), dampness on the electronics
no or too little gas,
ignition system (ignition transformer, ignition cable, ignition plug) defective,
interruption of the ionisation current (cable, electrode),
false gas setting, faulty earthing of the appliance, electronics defective
gas supply temporarily interrupted, flue gas recirculation,
faulty earthing of the appliance
fan jammed,
fan plug not inserted correctly,
fault in cable harness, electronics defective
pressure sensor not fitted or defective
(however, not short circuit or interruption)
no valid value for appliance variant
no valid value for appliance variant
short circuit/short-circuit to ground in the cable harness to the gas valves,
gas fitting defective (short-circuit to ground of the coils), electronics defective,
water pressure switch defective, flow switch defective
Short circuit/short-circuit to ground in the cable harness to the gas valves,
gas fitting defective (short-circuit to ground of the coils), electronics defective
water pressure switch defective, flow switch defective
gas fitting leaking, electronics defective
electronics defective
short circuit supply or return NTC, electronics defective
electronics too hot due to external influence, electronics defective
electronics defective
fan (hall sensor) defective, error in the cable harness, electronics defective
Troubleshooting 8
earth connection of the cable harness to
35