Vaillant VRC 700 Operating Instructions Manual - page 24
Appendix
23
B
Detecting and rectifying faults
Fault
Cause
Remedy
Display is dark
Appliance fault
–
Switch off the mains switch on all heat generators for ap-
prox. 1 minute and then switch them on again
–
If the fault is still present, inform the competent person
No changes in the display when the rotary
knob is turned
No changes in the display when the selec-
tion buttons are pressed
It is not possible to change the settings or
values
Display view:
Button lock active To un-
lock, press OK for 3 seconds
Button lock is active
If you want to change the values without deactivating the but-
ton lock:
1. Press and hold the OK button for three seconds.
2. Select the function for which you want to change a value.
3. Change the value.
After one minute of not pressing anything, the button lock is
reactivated.
If you want to deactivate the button lock:
1. Press and hold the OK button for three seconds.
2. Select the
Button lock
function.
3. Change the value to
Off
.
Insufficient heating-up of the heating and
the hot water
Heat pump does not
work
1. Inform the competent person.
Temporary settings until the competent person arrives:
2. Use the rotary knob to select the setting:
–
Inactive
: The controller works in limp home mode; heating
and hot water at a moderately warm temperature
–
Heating
*: The auxiliary heater takes over the heating
mode
–
DHW
*: The auxiliary heater takes over the hot water hand-
ling mode
–
DHW+heat.
*: The auxiliary heater takes over the heating
and hot water handling modes
*The auxiliary heater is not as efficient as the heat pump, meaning that using only the auxiliary heater to generate heat is expensive.
0020200782_00
VR
C 700
Operating instructions