ecoTEC plus 937 installation and maintenance manual56
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.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.1 Return NTC open circuit 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,
appliance does not shut down
F.22 Dry fire Too little water in the appliance, water pressure sensor defective,
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
transformer, ignition cable, ignition plug) defective, ionisation
current stopped (cable, electrode), faulty earthing in appliance,
electronics 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
defective, fault in cable harness, electronics defective
F.49 eBUS undervoltage Short-circuit on eBUS input, eBUS overload or two power
supplies 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
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
Table 8.4 Error codes (continuation see next page)
8 Troubleshooting
To Next Page
Loading...
Need help?
General
