Vaillant ecoTEC exclusive 835 Installation And Maintenance Instructions Manual page 56

Code Parameter
F.55 Fault: CO sensor
F.56 Safety switch-off: CO limit exceeded
F.57 Fault: Measuring program
F.61 Fault: Fuel valve actuation
F.62 Fault: Fuel valve switch-off delay
F.63 Fault: EEPROM
F.64 Fault: Electronics/sensor
F.65 Fault: Electronics temp.
F.67 Fault: Electronics/flame
F.68 Fault: Flame signal unstable
F.70 Fault: Invalid Device Specific Number
F.71 Fault: Flow sensor
F.72 Fault: Flow/return sensor
F.73 Fault: Water press. sensor
F.74 Fault: Water press. sensor
F.75 Fault: Pump/ water shortage
F.77 Fault: Flue non-ret. valve/condens. pump
F.78 Interrupt.: DHW outlet sensor on ext. contr.
F.80 Fault: actoSTOR inlet sensor
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Possible causes
Checking the cable harness
All-gas sensor defective, replace the all-gas sensor
Electronics defective, replace the PCB
Safety shutdown: CO limit value exceeded
A component in the combustion regulation is defective
–
Contact fault at the gas valve assembly (plug not plugged in cor-
rectly or not plugged in, plug defective, slot is defective (loose con-
nection))
–
If the fault occurs again after being reset: The gas valve assembly is
defective
Active comfort protection mode has detected a regulation fault
–
Ignition electrode highly corroded
The gas valve assembly cannot be actuated
–
Cable harness supply line to the gas valve assembly is defective
(short to earth, short circuit)
–
Gas valve assembly defective
–
PCB defective
Delayed switch-off sequence of gas valve assembly detected
–
Flame indicator light (ignition and monitoring electrode indicates
delayed extinguishing of the flame signal)
–
Gas valve assembly defective
–
PCB defective
Electronics defective
Flow or return NTC short circuited, electronics defective
Electronics overheating due to external influences, electronics defective
Implausible flame signal, electronics defective
Air in gas, gas flow pressure too low, incorrect air ratio, condensate
route blocked, ionisation flow interruption (cable, electrode), flue gas
recirculation, condensate route
If spare parts fitted: Display and PCB replaced at same time and DSN
not reset, incorrect or missing output coding resistor
Flow temperature sensor signalling constant value:
–
Flow temperature sensor incorrectly positioned on the flow pipe
–
Flow temperature sensor defective
Flow/return NTC temperature difference too great → flow and/or return
temperature sensor defective
Interruption/short circuit of water pressure sensor, interruption/short
circuit to GND in supply line to water pressure sensor or water pressure
sensor defective
The line to the water pressure sensor has a short circuit to 5 V/24 V or
internal fault in the water pressure sensor
Water pressure sensor and/or pump defective, air in the heating installa-
tion, insufficient water in the product; connect external expansion vessel
to the return
No response from flue non-return flap or condensate pump defective
UK link box is connected but the domestic hot water NTC is not bridged
Only in conjunction with F.91
NTC defective, NTC cable defective, defective plug connection on NTC,
defective plug connection on the actoSTOR electronics
Sensor plug has short to earth to the housing, short circuit in cable har-
ness, sensor defective
Installation and maintenance instructions ecoTEC exclusive 0020193968_05