Diagnostic Codes; First Diagnostic Level - Vaillant ecoTEC plus 937 Instructions And Maintenance Instructions

8.1.2

Diagnostic codes

In the diagnostic mode, you can change certain parame-
ters or display more information.
The diagnostic information is divided into two diagnostic
levels. Access to the second diagnostic level can only be
permitted after entering a password.
a Caution!
Danger of incorrect operation and wrong unit
parametrisation!
Access to the second diagnostic level must be
used exclusively by a heating engineer.

First diagnostic level

• Press the "i" and "+" buttons simultaneously.
The display shows "d.00".
Display Meaning
d.0 Heating partial load
d.1 Water pump over run time for heating mode
d.2 Max. anti cycle time heating at 20°C flow temperature
d.3 Measured value of the domestic hot water temperature
d.4 Measured value for the warmstart sensor
d.5 Flow temperature target value or return temperature tar-
get value, if return flow regulation selected
d.6 Hot water target temperature
d.7 Warm start target temperature
d.8 Heat demand of external controllers (terminal 3-4)
d.9 Flow target temperature from external analogue regulator
to terminal 7-8-9/eBus
d.10 Status internal heating pump
d.11 Status external heating pump (via accessory module)
d.12 Cylinder charging pump (via accessories module)
d.13 External hot water circulation pump (via accessory module)
d.22 Hot water demand
d.23 Summer /winter function
d.25 Hot water activation via eBUS controller
d.30 Control signal for both gas valves
d.33 Fan speed target value
d.34 Fan speed actual value
d.35 Internal diverter valve position
d.36 Hot water flow sensor
d.40 Flow temperature
d.41 Return flow temperature
d.44 digitalised ionisation voltage
d.47 External temperature (only on weather-compensated
Vaillant controllers)
d.67 Remaining burner anti-cycling time
d.76 Unit variants (device specific number)
d.90 Status of the digital controller
d.91 DCF status with connected external probe with DCF77 re-
ceiver (not available in the UK)
d.92 Module recognition shift load storage tank
d.97 Activation of the second diagnostic level
Table 8.2 Diagnostic codes of the first diagnosis level
Installation and maintenance instructions ecoTEC plus 0020031552_03
• Use the buttons "+" or "–" to move to the desired di-
agnostic number of the first diagnostic level (see the
Table 8.2).
• Press the "i" button.
The associated diagnostic information is shown in the
display.
• If necessary you can change the value with the but-
tons "+" or "–" (display flashing).
• Save the new value by holding down the "i" button for
approx. 5 seconds until the display no longer flashes.
You can end the diagnostic mode as follows:
• Press the "i" and "+" buttons simultaneously. or
• Do not press any button for about 4 minutes.
The current heating flow temperature appears in the
display again.
Displayed value/settable value
Adjustable heating partial load in kW (factory setting: max. output)
2 - 60 minutes (factory setting: 5 minutes)
2 - 60 minutes (factory setting: 20 minutes)
in °C
in °C
in °C, max. of the value set in d.71
limited by an eBUS controller, if fitted)
in °C, 35 to 65 °C
in °C, 40 to 65 °C
1=closed (heating requirement); 0=opened (no heating requirement)
in °C, minimum from ext. eBus target value and target value
terminal 7
1, 2 = on, 0 = off
1 to 100 = on, 0 = off
1 to 100 = on, 0 = off
1 to 100 = on, 0 = off
1 = on, 0 = off
1 = Winter, 0 = Summer
1 = yes, 0 = no
1 = on, 0 = off
in upm/10
in upm/10
0 = heating; 100 = hot water; 40 = mid-position
in l/min
actual value in °C
actual value in °C
Display range 0 to 102, >80 no flame, <40 good flame display
actual value in °C
in minutes
00 to 99
1 = identified, 0 = unidentified (eBUS Address <=10)
0 = no reception, 1 = reception, 2 = synchronised, 3 = valid
Setting range:
0 = not recognised
1 = no communication via PE-BUS; Module recognised earlier
2 = Communication OK
Setting = 0: Unregister shift load storage tank from combi boiler
(if shift load storage tank is to be de-installed, set d.92 = 0)
Password: 17
Troubleshooting 8
47