Rooms Are Too Cold; Rooms Are Too Hot - Viessmann VITOLIGNO 250-S Operating Instructions Manual

What to do if...

Rooms are too cold

Cause
Central heating is switched off.
Control unit incorrectly set.
The temperatures of the heating water buffer cylinder
and the boiler water are low.
Control unit fault:
"Fault" is displayed; the red fault indicator flashes.
The heating circuit pump is not working.
Heating circuit with mixer: Mixer motor faulty

Rooms are too hot

Cause
Control unit incorrectly set.
Control unit fault or outside temperature sensor/boiler
water temperature sensor faulty:
"Fault" is displayed; the red fault indicator flashes.
Heating circuit with mixer: Mixer motor faulty
40
Remedy
Check the room thermostats. If necessary, change the
operating program.
Check the settings and correct if required:
The heating circuit must be ON (see page 21)
■
Room temperature (see page 20)
■
Time (see page 32)
■
Switching times (see page 22)
■
Charge the boiler with fuel. Heat up the boiler again.
Check the type of fault (see page 37) and notify your
heating contractor.
Contact your heating contractor.
Unhook motorised lever
ually (e.g. to "5").
Notify your heating contractor.
Remedy
Check the settings and correct if required:
The heating circuit must be ON (see page 21)
■
Room temperature (see page 20)
■
Time (see page 32)
■
Switching times (see page 22)
■
Check the type of fault (see page 37) and notify your
heating contractor.
Unhook motorised lever
ually (e.g. to "5").
Notify your heating contractor.
. Adjust mixer lever
A B
. Adjust mixer lever
A B
man-
man-