Rooms Are Too Cold; Rooms Are Too Hot - Viessmann VITODENS Operating Instructions Manual

Rooms are too cold

Cause
The heating system is switched off.
Control unit or room temperature controller is not set
correctly.
Only when operating with DHW heating:
DHW heating priority is active: "
No fuel.
" " is shown on the display.
" " is shown on the display.

Rooms are too hot

Cause
Control unit or room temperature controller is incorrect-
ly set.
" " is shown on the display.
Remedy
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■
Check settings and correct if required:
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■
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■
Wait until the DHW cylinder has been heated up: "
" is displayed 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 24.
Notify your contractor if the burner still fails to start.
Acknowledge the fault message with OK: See page 19.
Notify your contractor of the fault code shown.
Acknowledge the fault message with OK: See page 19.
Remedy
Check settings and correct if required:
■
■
■
Inform your contractor of the fault code.
Acknowledge the fault message with OK: See page 19.
Turn on the ON/OFF switch " ": See page 23.
Switch on the mains isolator, if installed (outside the
boiler room).
Switch on the fuse in the power distribution board
(main domestic fuse).
" " must be set: See page 13.
Room temperature
Operating instructions for room temperature
controller
Flow temperature: See page 13.
Time program
Operating instructions for room temperature
controller
Danger
If faults are not rectified, they can have life
threatening consequences.
Do not acknowledge fault messages several
times in quick succession. Notify your contractor
if a fault recurs. Your contractor will be able to
analyse the cause and rectify the fault.
Room temperature
Operating instructions for room temperature
controller
Flow temperature: See page 13.
Time program
Operating instructions for room temperature
controller
What to do if...
"
25