Rooms Are Too Cold - Viessmann VITOTRONIC 300 Operating Instructions Manual

Troubleshooting

Rooms are Too Cold

Cause
The heating system is off
Control unit or remote control incorrectly set.
Only when operating with DHW heating:
DHW priority is enabled.
No fuel.
Slab curing function for slab curing drying is
active. (Not used)
"Fault" is displayed, and the red fault indicator
flashes.
Burner start faulty
"Fault" is displayed and the red fault indicator
on the burner is illuminated.
Mixing valve motor faulty.
30
Remedy
- Switch the ON/OFF switch ON (see diagram on page 10).
- Switch ON the mains isolator, if installed (outside the boiler room).
- Reset the MCB in the power distribution board
(main domestic MCB).
Check settings and correct if required:
- "Heating and DHW" must be selected (see page 14).
- Room temperature (see page 13).
- Time (see page 25).
- Time program (see page 14).
- Check the settings at the remote control (if available).
Separate operating instructions
Wait until the DHW tank has been heated up.
With fuel oil or 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.
Wait until the slab curing drying time has elapsed. (Not used)
Scan the type of fault, make a note of the fault code
and acknowledge the message (see page 28).
Contact your local heating contractor if required.
Press the reset button on the burner. If there is no reset button,
switch the ON/OFF switch (see diagrams on page 10) first OFF and
then ON again.
Contact your local heating contractor if the burner still fails to start.
Adjust the mixing valve manually.
Vitotronic 300, GW5B Operating