Running Test Programs; Resetting Parameters To Factory Settings - Vaillant ecoTEC VU Installation And Maintenance Instructions Manual

Code Meaning
F.68 Unstable flame signal fault
F.70 Invalid device specific number (DSN)
F.71 Flow NTC fault
F.72 Flow/return NTC fault
F.73 Water pressure sensor signal in the wrong range
(too low)
F.74 Water pressure sensor signal outside correct
range
(too high)
F.75 Fault, no pressure change detection when start-
ing pump
F.76 Overheating protection on primary heat
exchanger has responded
F.77 Flue non-return flap/condensate pump fault
F.78 Interruption to DHW outlet sensor at external
controller
F.83 Flow and/or return temperature sensor tempera-
ture change fault
F.84 Fault: Flow/return temperature sensor tempera-
ture difference implausible
F.85 Fault: Flow and return temperature sensors incor-
rectly fitted
connec- No communication with the PCB
tion
13.2 Fault codes (continued)
13.3

Running test programs

By activating various test programs, you can trigger special
functions on the boiler (¬ table. 10.1). The display shows
which test program you have chosen.
> Read how to start the test programs in ¬ section 10.2.
13.4

Resetting parameters to factory settings

As well as the option to manually reset individual parame-
ters to the default settings specified in ¬ table 11.1, you can
also reset all parameters at once.
> Set the value of the diagnosis code parameter D.096 to
"1" (¬ section 11.1).
You have now reset all parameters to factory settings.
Installation and maintenance instructions ecoTEC 0020173113_01
Cause
Air in gas, gas flow pressure too low, wrong air ratio, condensate route
blocked, wrong gas restrictor, ionisation flow interruption (cables, elec-
trodes), flue gas recirculation, condensate route
Spare part case: Display and PCB changed at the same time and appliance
code not reset
Flow temperature sensor signalling constant value:
- Flow temperature sensor incorrectly positioned at supply pipe.
- Flow temperature sensor defective.
Flow/return NTC temperature difference too great -> flow and/or return
temperature sensor defective
Interruption/short circuit of water pressure sensor, interruption/short cir-
cuit to GND in supply line to water pressure sensor or water pressure sen-
sor defective
Cable to water pressure sensor has short-circuited at 5 V/24 V
or internal fault in water pressure sensor
Water pressure sensor and/or pump defective, air in heating installation,
too low water pressure in boiler; check adjustable bypass, connect external
expansion vessel to return
Cable or cable connections for safety fuse in primary heat exchanger or
primary heat exchanger defective
No response from flue non-return flap or condensate pump defective
UK link box is connected, but hot water NTC not bridged
When the burner starts, the temperature change registered at flow and/or
return temperature sensor is non-existent or too small.
- Not enough water in the boiler
- Flow and/return temperature sensor not in correct position at pipe.
Flow and return temperature sensors returning implausible values.
- Flow and return temperature sensors have been inverted.
- Flow and return temperature sensors have not been correctly fitted.
Flow and/or return temperature sensors
have been fitted to the same pipe/wrong pipe.
Communication fault between display and PCB in the electronics box
Troubleshooting 13
63