Vailant ecoTEC plus 937, Installation And Maintenance Instructions Manual

Page: 63 / 80

Installation and maintenance instructions ecoTEC plus 937 0020031552_06
63
Code Meaning Cause
F.0 Flow NTC open circuit
NTC faulty, NTC cable faulty, faulty plug connection on NTC,
faulty plug connection on the electronics
F.01 Return NTC open circuit
NTC faulty, NTC cable faulty, faulty plug connection on NTC,
faulty plug connection on the electronics
F.02
Shift load storage tank charging (NTC) open circuit,
only in combination with F.91 NTC faulty, NTC cable faulty, faulty plug connection on NTC,
faulty plug connection on the electronics
F.03
Shift load storage tank temperature (NTC) open circuit,
only in combination with F.91 NTC faulty, NTC cable faulty, faulty plug connection on NTC,
faulty plug connection on the electronics
F.10 Flow NTC short circuit NTC faulty, NTC plug short-circuited to casing
F.11 Return NTC short circuit NTC faulty, NTC plug short-circuited to casing
F.12
Short circuit in storage tank charging sensor (NTC)
only in combination with F.91 Sensor plug has mass short to the casing, short-circuit in wiring
loom, sensor faulty
F.13
Short circuit storage tank temperature sensor (NTC)
only in combination with F.91 Sensor plug has mass short to the casing, short-circuit in wiring
loom, sensor faulty
F.20 Safety temperature limiter by NTC activated
Flow probe not connected thermally correct or defective, appli-
ance does not shut down
F.22 Dry fire
Too little water in the appliance, water pressure sensor defec-
tive, cable to pump or water pressure sensor defective, pump
seized or defective, pump output too low
F.23
Water shortage, temperature spread between flow and
return NTC too large Pump seized or defective, pump output too low, flow and return
sensor swapped over
F.24 Water shortage, temperature rise too quick
Pump seized, low output from the pump, air in appliance, system
pressure too low
F.25 Compact thermal module wiring harness open circuit Wiring harness thermo-compact module faulty
F.27 Incorrect sensing of flame Flame monitor faulty
F.28 Unit will not start: Attempts to ignite during start failed
Faults in the gas supply such as:
- Gas meter or gas pressure regulator
- Air in gas
- Gas flow pressure too low
Faults in the gas valve, wrong gas setting, igniter (ignition trans-
former, ignition cable, ignition plug) defective, ionisation current
stopped (cable, electrode), faulty earthing in appliance, electron-
ics defective
F.29
Flame goes off during operation and subsequent ignition
attempts failed Gas supply temporarily interrupted, defective earthing of the
unit
F.32 Speed deviation Fan
Fans seized, plug not inserted correctly on fan, hall sensor defec-
tive, fault in cable harness, electronics defective
F.49 eBUS undervoltage
Short-circuit on eBUS input, eBUS overload or two power sup-
plies with different polarities on the eBUS
F.61 Gas valve control faulty
Short circuit/earth(ground) leak in cable harness to gas valve,
gas valve assembly defective (earth/ground leak from solenoid),
electronics fault.
F.62 Switch-off delay of the gas valve faulty gas valve leaking, electronics defective
F.63 EEPROM error Defective electronics
F.64 Electronics/NTC fault
Short-circuit in flow or return NTC or electronics defective/ air in
gas
F.65 Electronics temperature too high Electronics too hot due to external effect, electronics defective
F.67 Flame monitor input signal is outside the limits (0 or 5 V) electronics defective
F.70
No valid appliance variant for display and/or electronics
(DSN number invalid) Spare parts error: Display and electronics changed at the same
time appliance variant not re-set
F.71 Flow NTC reports constant value Flow NTC is defective
F.72 Flow and/or return NTC fault Feed and/or return NTC is faulty (tolerance too great)
F.73
Signal water pressure sensor in the wrong range
(too low) Line to water pressure sensor is interrupted or has a short-cir-
cuit to 0 V or water pressure sensor faulty
Table 9.4 Error codes
Troubleshooting 9