Rooms Are Too Cold - Viessmann VITODENS Operating Instructions Manual

What to do if...

Rooms are too cold

Cause
The heating system is switched off.
Control unit incorrectly adjusted.
■
The remote control (if installed) is set incorrectly.
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Separate operating instructions
The DHW cylinder is being heated.
No fuel.
"Burner fault" is displayed.
"Fault" is displayed. The red fault indicator flashes.
"Screed drying" is activated.
The mixer motor is faulty.
In conjunction with a mechanical ventilation unit:
Bypass does not close.
■
Preheating coil faulty.
■
Supply/extract air fan faulty.
■
48
Remedy
Switch ON the ON/OFF switch (see page 27).
■
Switch ON the mains isolator if installed (outside the
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boiler room).
Set the MCB in the power distribution board (main do-
■
mestic MCB).
Central heating must be enabled.
Check the settings and correct if required:
Operating program (see page 15)
■
Room temperature (see page 29)
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Time (see page 42)
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Time program, central heating (see page 30)
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Heating curve (see page 30)
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Wait until the DHW cylinder has been heated up.
Reduce the DHW draw-off rate or temporarily reduce
the DHW temperature as required.
For operation with LPG:
Check the fuel reserves and re-order if required.
For operation with natural gas:
Open the gas shut-off valve. If necessary, check with
your gas supply utility.
Press button R (see page 27).
Acknowledge the fault (see page 45).
Danger
If faults are not rectified, they can have life
threatening consequences.
Do not acknowledge fault messages several
times in quick succession. Notify your heating
contractor if a fault recurs. Your heating contrac-
tor will be able to analyse the cause and rectify
the fault.
Check what type of fault it is. Acknowledge the fault
(see page 45). If necessary, notify your heating contrac-
tor.
No action required.
After expiry of the screed drying time, the selected op-
erating program will become active.
Adjust the mixer manually.
Notify your heating contractor.