Error Codes; Error Memory - Vaillant ecoMAX 646 Installation And Maintenance Manual

8 Troubleshooting
8.1.3

Error codes

The error codes displace all other displays when errors
occur. An error that arises is shown in the display as
"F...", e.g. "F.10" (see table on the next page). If several
errors occur simultaneously, the corresponding error
codes are displayed alternately for approx. 2 seconds
each.
8.1.4

Error memory

The last 10 errors are saved in the appliance error
memory.
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)
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.37 Fan turning-speed malfunction
(too fast or too slow during operation)
F.42 Coding resistor - short circuit
F.43 Coding resistor - open circuit
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)
Emergency No speed signal from the fan Hall sensor
run "speed"
Table 8.3 Error codes
32
• Press the "i" and "–" keys simultaneously.
• You can scroll back through the error memory by
pressing the "+" key.
You can exit the error memory display as follows:
• Press the "i" key beneath the display
or
• do not press any key for about 4 minutes.
The current heating supply temperature appears in the
display again.
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 defec-
tive, 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
Fan unit obstructed or blocked with debris, plug–in fan connector not cor-
rectly inserted, Hall effect sensor defective, fault in cable loom, defective
electronic control system. Fan motor and bearings sticking with debris.
Faulty cable loom (X2) defective electronic control system.
Wiring plug X 2 is not firmly located in the plug, 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
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
Wiring cable on the fan is not firmly located, fault in cable loom, defective
electronic control system.
Installation and maintenance manual ecoMAX 646 / 0020020158_02