Vaillant ecoMAX SERIES Instructions For Installation And Servicing page 49

Key to Fault codes
Code Meaning
F.0 Flow–NTC:
– NTC broken
– NTC cable broken
– Defective connection at NTC
– Defective connection at electronics
F.1 Return–NTC:
– NTC broken
– NTC cable broken
– Defective connection at NTC
– Defective connection at electronics
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 Low water or no water in appliance
F.23 Water level low
Temperature range too wide
F.24 Water level low
Temperature rises too fast
F.25 Water Switch
System pressure too low
F.27 No demand to gas valve
F.28 Boiler goes to lock out
F.29 Flame extinguished re–ignition unsuccessful
F.32 Fan turning–speed malfunction
(too fast at start–up)
F.60 Gas–valve control + defective
F.61 Gas–valve control – defective
F.62 Defective gas–valve closure mechanism
F.63 EEPROM error
F.64 Electronic system/sensor fault
F.65 Electronic system temperature too high
F.67 Electronic fault in flame system
(non–plausible flame signal)
Table 8.3
Instructions for installation and servicing ecoMAX
Cause
Flow–NTC cable defective/broken NTC faulty
Return–NTC cable defective/broken NTC faulty
NTC– plug shorted to casing, NTC defective
NTC– plug shorted to casing
NTC defective, earth leak/short circuit in cable loom,
damp plug connection
Maximum temperature exceeded
No water in system
Pump defective
Pump lead defective
Pump obstructed, pump running at lower capacity,
Air in appliance, system pressure too low,
flow and backflow NTC reversed
Pump obstructed, pump running at lower capacity,
ir in appliance, system pressure too low,
flow and backflow NTC reversed
Water Switch - plug disconnected
Waterswitch activated
Electronic board defective
Gas valve defective
No gas
Insufficient gas
Incorrect gas valve adjustment
Electrode defective
Ignition lead defect
Electronic igniter defective
Check air inlet duct
Gas supply absent or insufficient
Check flue duct
Fan unit obstructed, plug–in fan connector not
correctly inserted, Hall sensor defective, fault in cable
loom, defective electronic control system
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
Leak in gas valve assembly, electronic fault
Electronic fault
Short circuit in flow or backflow NTC,
electronic fault
Electronic system affected by external heat source,
electronic fault
Electronic fault
Troubleshooting 8
49 49