Troubleshooting 8; Logical Fault Finding Procedure; Status Codes; Diagnostic Codes - Vaillant ecoTEC SERIES Instructions For Installation And Servicing

8 Troubleshooting
8.1

Logical fault finding procedure

These checks must be carried out before attempting to
use the fault finding guide.
1. Carry out electrical safety checks (see section
'Preliminary Electrical Checks').
2. Check that the external electricity supply to the boiler
is on, and a supply of 230 V~ is present between
boiler terminals 'L' and 'N'.
3. Check that the gas supply to the boiler is on, that it has been
correctly purged and that an inlet pressure of 20 mbar is
available at the gas valve. (See section 'Gas Supply').
4. Ensure the heating system is full of water and charged
to between 1 and 1.5 bar. If not, refill and vent the
system. (See section 'Filling the heating system').
Ensure boiler flow and return service valves are open.
5. Check that the main on/off control is set to the 'on' position.
6. Set the central heating temperature to maximum.
7. Set the domestic hot water temperature to maximum
(combination boilers only).
8. Check that all external controls are on and calling for
heat (if no external controls are fitted, boiler terminals
3 and 4 must be linked). Check that the boiler anti–
cycling economiser is not engaged.

8.1.1 Status codes

The status codes that you can see on the display
provides information about the current operating
condition of the appliance. The display of the status
codes can be called as follows:
plus
Fig. 8.1 Display of status codes
• Press the "i" key.
The display shows the status code, e.g. S.4 for "Burner
mode - Heating".
The display of the status codes can be cancelled as follows:
• Press the "i" key or
• Do not press any key for about 4 minutes.
The current heating flow temperature appears in the
display again.
Instructions for installation and servicing ecoTEC 839592_12

8.1.2 Diagnostic codes

pro
Table 8.1 Status codes (continued)
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
S.32 variation 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
S.42
condensate 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
S.96
heating) 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

Troubleshooting 8

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