Vaillant VR 91f Operating And Installation Instructions page 21

Symptom
No changes in the
display when the
rotary knob is turned
No changes in the
display via the se-
lection buttons are
pressed
Display view: No RF
communication
It is not possible to
switch to the installer
level
0020253110_03 Operating and installation instructions
Possible cause
Software error
The product is defect-
ive
Software error
The product is defect-
ive
No power supply to
the radio receiver unit
The remote control
is outside the radio
reception range
The product is defect-
ive
You do not know the
code for the installer
level
Measure
1. Take all the batteries out.
2. Insert the batteries in the battery compart-
ment, making sure that the poles are the
right way round.
▶
Replace the product.
1. Take all the batteries out.
2. Insert the batteries in the battery compart-
ment, making sure that the poles are the
right way round.
▶
Replace the product.
▶
Reconnect the power supply to the radio
receiver unit.
1. Take the remote control to the radio
receiver unit and see if the reception
strength increases.
If the reception strength is ≤ 4, find a new
2.
installation site for the remote control.
▶
Replace the product.
▶
Reset the remote control to the factory set-
tings (→ Page 14).
21