What To Do If; Rooms Are Too Cold - Viessmann VITODENS 100-W Operating Instructions Manual

Rooms are too cold

Cause
The heating system is off.
Control unit or room temperature control
unit incorrectly adjusted.
Only when operating with DHW heating:
DHW priority is enabled (" " is dis-
played).
No fuel.
The "U" symbol is shown on the display.
Symbol "U" flashes on the display. The
burner does not start.
Air in the heating system.
The burner is switched off. Blockage in
the ventilation air supply or flue system.
Remedy
■ Turn on the ON/OFF switch " " (see
figure on page 8).
■ Switch ON the mains isolator, if instal-
led (outside the boiler room).
■ Reset the MCB in the power distribution
board (main domestic MCB).
■ " " has to be adjusted (see page 13).
■ Check and correct the heating water
temperature at rotary selector "
" (see page 13).
■ For room temperature control unit:
Check and correct the room tempera-
ture required (see operating instruc-
tions for the room temperature control
unit).
Wait until the DHW cylinder has been
heated up (" " symbol disappears).
In the case of operation with an instanta-
neous 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.
Notify your heating contractor of the fault
code shown.
Reset the burner fault (see page 20).
Bleed radiators.
Notify your local heating contractor.

What to do if...

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