Vaillant ecoTEC plus 612 Instructions For Installation And Servicing page 48

8 Troubleshooting
Code Meaning
F.00 Flow–NTC:
NTC broken, NTC cable broken, Defective connection at
NTC, Defective connection at electronics
F.01 Return–NTC:
NTC broken, NTC cable broken, Defective connection at
NTC, Defective connection at electronics
F.02 Drinking water outlet probe stopped (<-10 °C)
(800 series only)
F.10 Short circuit – flow–NTC (< 130 °C)
F.11 Short circuit – return–NTC (< 130 °C)
NTC defective
F.13 Short circuit in tank sensor
F.20 Over heat cut off activated
F.22 Dry fire
F.23 Water shortage, temperature spread between flow and
return probe too large
F.24 Water shortage, temperature rise too quick
F.27 Secondary light, the ionisation signal reports a flame in
spite of gas valve being turned off
F.28 Appliance does not start: Attempts to ignite during start
failed
F.29 Flame goes off during operation and subsequent ignition
attempts failed
F.32 Fan speed variation (too high on start)
F.60 Gas–valve control + defective
F.61 Gas–valve control – defective
F.62 Gas valve shutoff delay defective
F.63 EEPROM error
F.64 Electronics/sensor fault
F.65 Electronics temperature too high
F.70 No valid DSN in AI and/or BMU
F.71 Flow sensor reports constant value
F.72 Flow and/or return sensor fault
F.73 Water pressure sensor or cable harness hydraulics
defective
F.74 Water pressure sensor or cable harness defective
F.75 No sudden change in pressure was detected on turning
on the pump
F.76 Overheating protection on primary heat exchanger trig-
gered, damage in primary heat exchanger
Table 8.4 Error codes
48
Cause
Flow–NTC cable defective/broken, NTC faulty
Return–NTC cable defective/broken, NTC faulty
NTC-connector not plugged in or loose, NTC defective multiconduc-
tor on the electronics not plugged in correctly, cable defective
NTC– plug shorted to casing, NTC defective
NTC– plug shorted to casing
NTC defective, earth leak/short circuit in cable loom,
damp plug connection
Flow probe not correctly thermal-connected or defective, appliance
does not shut down
Too little water in the appliance, water shortage switch defective,
cable to pump or water shortage switch defective, pump blocked or
defective, pump output too low
Pump blocked or defective, pump output too low
Pump blocked, insufficient pump output, air in appliance, plant pres-
sure too low, flow and return NTC interchanged
Secondary light, gas solenoid valves defective, flame detector
defective
Faults in the gas supply such as:
- Gas meter or gas pressure detector defective
- Air in gas
- Gas flow pressure too low
- Fire protection tap has disengaged
Faults in the gas fitting (main gas magnet or operator defective),
wrong gas setting, igniter (ignition transformer, ignition cable, igni-
tion plug) defective, ionisation current stopped (cable, electrode),
faulty earthing in appliance, electronics defective
Gas supply temporarily stopped, ignition transformer has spark fail-
ure, faulty earthing of appliance
Fans blocked, plug not inserted correctly on fan, hall sensor defec-
tive, fault in cable harness, electronics defective
Short circuit/earth (ground) leak in cable loom to gas valves, gas
valve assembly defective (earth/ground leak from coils), electronic
control system defective
Short circuit/earth (ground) leak in cable loom to gas valves, gas
valve assembly defective (earth/ground leak from coils), electronic
control system defective
Gas fitting leaking, electronics defective
Electronics defective
Short-circuit in flow or return sensor or electronics defective
Electronics too hot due to external effect, electronics defective
Spare part failure AI and motherboard interchanged at same time
Flow sensor is defective
Flow and/or return sensor is defective
Line to water pressure sensor is broken or has a short-circuit at 0 V
or water pressure sensor defective
Line to water pressure sensor has a short-circuit at 5 V / 24 V or
internal fault in water pressure sensor
Water pressure sensor or/and pump defective
Too little water in appliance; check adjustable by-pass
Cable or cable connection of fuse in the primary heat exchanger
defective, replace primary heat exchanger
Instructions for installation and servicing ecoTEC