When Rooms Are Too Hot; When There Is No Hot Water - Viessmann VITODENS Operating Instructions Manual

What to do

When rooms are too hot

Cause
The control unit or the remote control
unit is incorrectly adjusted
Control unit fault: U is displayed and
the red fault indicator flashes

When there is no hot water

Cause
Heating system is switched OFF
ON/OFF indicator 8 (green) is OFF
Control unit incorrectly adjusted
No fuel
Control unit fault: U is displayed and
the red fault indicator flashes
Burner fault: The red fault indicator of
the control unit flashes and "E" is dis-
played
20
Remedy
Check the room temperature setting
and correct, if required
Check the type of fault (see page 21)
and notify your heating contractor
Remedy
Switch ON system ON/OFF switch 8
&
(see page 10)
&
Switch ON mains electrical isolator, if
installed (outside boiler room)
&
Check the circuit breaker inside
power distribution (main domestic
fuse) and reset it, if required
Check settings and correct if required:
&
DHW heating must be switched ON
(see page 12)
& DHW temperature (see page 15)
Oil/LPG:
Check fuel level and re-order fuel, if re-
quired.
Natural gas:
Open the gas shut-off valve and check
with your gas supplier, if required.
Check the type of fault (see page 21)
and notify your heating contractor
Press burner fault reset "E" – if that
attempt to start also fails, notify your
heating contractor.