Diagnostic Codes - Vaillant ecoTEC plus 612 Instructions For Installation And Servicing

8 Troubleshooting

8.1.2 Diagnostic codes

Display Meaning
Heating mode (all models):
S. 0 No heat demand
S. 1 Fan running
S. 2 Water pump running
S. 3 Ignition sequence
S. 4 Burner ignited
S. 5 Fan and pump running
S. 6 Fan over run
S. 7 Pump over run
S. 8 Anti cycling mode
Domestic hot water mode (ecoTEC combination boilers only):
S.10 Hot water demand
S.11 Fan running
S.13 Ignition sequence
S.14 Burner ignited
S.15 Fan and pump running
S.16 Fan over run
S.17 Pump over run
Warm start (ecoTEC combination boilers only) / Charge hot
water cylinder (ecoTEC system boilers only):
S.20 Warmstart demand
S.21 Fan running
S.22 Pump running
S.23 Ignition sequence
S.24 Burner ignited
S.25 Fan and water pump running
S.26 Fan over run
S.27 Pump over run
S.28 Anti cycling mode
All boilers:
S.30 No heating demand from external controls (clamp 3-4 open)
Central heating thermostat knob turned off or no heat
S.31
demand by the eBUS control unit
Heat exchanger antifreeze active, as fan speed varia-
S.32 tion is too high. Appliance is within the waiting time of
the operation block function
S.34 Antifrost mode active
S.36 No heating demand from low voltage controls (clamp 7-8-9)
S.41 Water pressure > 2,9 bar
Response from accessory modul or defective conden-
S.42
sate pump is blocking burner operation
S.52 Water pressure > 2,9 bar
Appliance is within the waiting period of the operation
S.53 block function due to water shortage (VL-RL spread
too big)
Appliance is within the waiting period of the operation
S.54 block function due to water shortage (temperature
gradient)
Return-sensor check is running, demand (DHW or heat-
S.96
ing) is blocked
Water pressure sensor check is running, demand (DHW
S.97
or heating) is blocked
Flow-/Return-sensor check is running, demand (DHW
S.98
or heating) is blocked
Table 8.1 Status codes (continued)
42
In the diagnostic mode, you can change certain parame-
ters or display more information.
The diagnostic information is divided into two diagnostic
levels. The second diagnostic level can be reached only
after entering a password.
Caution!
Access to the second diagnostic level must be
used exclusively by a qualified technician.
First Diagnostic level
• Press the "i" and "+" keys simultaneously.
The display shows "d.0".
• Use the "+" or "–" keys to scroll through the desired
diagnostic numbers of the first diagnostic level (see
table 8.2).
• Press the "i" key.
The display shows the relevant diagnostic information.
• If necessary, use the "+" or "–" keys to change the
value (display flashes).
• Save the new value by holding down the "i" key for
approx. 5 seconds until the display no longer flashes.
You can end the diagnostic mode as follows:
• Press the "i" and "+" keys simultaneously.
or
• Do not press any key for approx. 4 minutes.
The current heating flow temperature appears in the
display again.
Instructions for installation and servicing ecoTEC / 839592_09