What To Do If; Rooms Are Too Cold; Rooms Are Too Hot; There Is No Hot Water - Viessmann VITODENS Operating Instructions Manual

What to do if...

Rooms are too cold

Cause
The heating system is switched off.
Control unit or room temperature control unit incorrectly
adjusted.
Only when operating with DHW heating:
DHW priority is enabled ("
No fuel.
Symbol " " is shown on the display.
Symbol " " is shown on the display.

Rooms are too hot

Cause
Control unit or room temperature control unit incorrectly
adjusted.
Symbol " " is displayed.

There is no hot water

Cause
The heating system is off.
Control unit incorrectly adjusted.
20
" is displayed).
Remedy
Turn ON/OFF switch " " on (see page 9).
■
Switch ON the mains isolator, if installed (outside the
■
boiler room).
Reset the MCB in the power distribution board (main
■
domestic MCB).
Check settings and correct if required:
" " must be set (see page 11)
■
Room temperature or boiler water temperature (see
■
page 11)
Time program
■
Room temperature control unit operating in-
structions
Wait until the DHW cylinder has been heated up ("
symbol disappears).
In the case of operation with an instantaneous water
heater, stop DHW draw-off.
With LPG:
Check the fuel reserves and re-order if required.
With natural gas:
Open the gas shut-off valve. If necessary, check with
your gas supply utility.
Press "R" (see page 9).
Acknowledge the fault message with OK (see page 16).
Notify your heating contractor of the fault code if the
fault recurs.
Notify your heating contractor of the fault code shown.
Acknowledge the fault message with OK (see page 16).
Remedy
Check settings and correct if required:
Room temperature or boiler water temperature (see
■
page 11)
Time program
■
Room temperature control unit operating in-
structions
Notify your heating contractor of the fault code.
Acknowledge the fault message with OK (see page 16).
Remedy
Turn ON/OFF switch " " on (see page 9).
■
Switch ON the mains isolator, if installed (outside the
■
boiler room).
Reset the MCB in the power distribution board (main
■
domestic MCB).
Check settings and correct if required:
DHW heating must be enabled (see page 12).
■
DHW temperature (see page 12).
■
"