Troubleshooting
Installation and maintenance instructions ecoTEC pro 0020129672_03
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13
13.2.9 Overview of fault codes
Code
Meaning
Cause
F.00
Flow temperature sensor interruption
NTC plug not plugged in or has come loose, multiple plug on the PCB
not plugged in correctly, interruption in cable harness, NTC defective
F.01
Return temperature sensor interruption
NTC plug not plugged in or has come loose, multiple plug on the PCB
not plugged in correctly, interruption in cable harness, NTC defective
F.10
Flow NTC short circuit
NTC defective, short circuit in cable harness, cable/casing
F.11
Return NTC short circuit
NTC defective, short circuit in cable harness, cable/casing
F.20
Safety switch-off: temperature limiter
Incorrect earth connection between cable harness and boiler, flow or
return NTC defective (loose connection), black discharge via ignition
cable, ignition plug or ignition electrode
F.22
Safety switch-off: low water pressure
No water pressure, or water pressure is too low in the boiler, water pres-
sure sensor defective, cable to pump or water pressure sensor loose/not
connected/defective
F.23
Safety switch-off: Temperature difference too great Pump blocked, insufficient pump output, air in boiler, flow and return
NTC interchanged
F.24
Safety switch-off: Temperature rise too fast
Pump blocked, poor pump performance, air in boiler, system pressure
too low, non-return valve blocks/incorrectly installed
F.25
Safety switch-off: Flue gas temperature too high
Break in plug connection for optional flue gas safety thermostat (STB),
break in cable harness
F.26
Fault: Gas valve without function
Gas valve stepper motor not connected, multiple plug on the PCB not
plugged in correctly, interruption in cable harness, gas valve stepper
motor defective, electronics defective
F.27
Safety switch-off: Flame simulation
Moisture on the electronics, electronics (flame monitor) defective, gas
solenoid valve leaking
F.28
Failure during start-up: ignition unsuccessful
Gas meter defective or gas pressure regulator has triggered, air in gas,
gas flow pressure too low, thermal isolator device (TAE) has triggered,
condensate duct blocked, incorrect gas restrictor, incorrect ET gas valve,
fault on the gas valve, multiple plug on PCB incorrectly plugged in, break
in cable harness, ignition system (ignition transformer, ignition cable,
ignition plug, ignition electrode) defective, ionisation current interrupted
(cable, electrode), incorrect earthing of boiler, electronics defective
F.29
Failure during operation: Re-ignition unsuccessful
Gas supply temporarily stopped, flue gas recirculation, condensate duct
blocked, faulty earthing of boiler, ignition transformer has spark failure
F.32
Fan fault
Plug at fan not correctly plugged in, multiple plug on PCB not correctly
plugged in, break in cable harness, fan blocked, Hall sensor defective,
electronics defective
F.49
eBUS fault
Short circuit on eBUS, eBUS overload or two power supplies with differ-
ent polarities on the eBUS
F.61
Fault: Gas valve regulation
- Short circuit/short to earth in cable harness for the gas valve
- Gas valve defective (coils shorted to earth)
- Electronics defective
F.62
Fault: Gas valve switch-off delay
- Delayed shutdown of gas valve
- Delayed extinguishing of flame signal
- Gas valve leaking
- Electronics defective
F.63
EEPROM error
Electronics defective
F.64
Electronics/NTC fault
Supply or return NTC short circuited, electronics defective
F.65
Electronic temperature fault
Electronics overheating due to external influences, electronics defective
F.67
Electronics/flame fault
Implausible flame signal, electronics defective
13.2 Fault codes
