Viessmann Vitocal 300-G BW, Installation And Service Instructions Manual

Page: 125 / 216

125
ID Characteristics and effects of system/control unit
40
48 Mixer heating circuit M2 is closed.
41
49 Mixer heating circuit M3 is closed.
44
4C Cooling mode" natural cooling" without regulating the flow. Control via exter-
nal humidity sensor and frost stat.
50
58 Use of the lower cylinder temperature sensor. DHW heating and heating by
the solar heating system will be blocked if only one sensor is available or both
sensors are faulty.
52
5A Use of the upper cylinder temperature sensor. DHW heating and heating by
the solar heating system will be blocked if only one sensor is available or both
sensors are faulty.
60
68 The cylinder is heated once every hour. Shutdown through the return tem-
perature sensor.
63
6B External heat source is blocked. The instantaneous heating water heater (if
installed) is enabled.
70
71
72
78
79
7A ■ No frost protection mode via room temperature sensor
■ No room temperature hook-up
■ No room temperature control
D6 The heat pump will not start
Powe
r-OFF The power-OFF (triggered by the power supply utility) is enabled longer than
12 hours.
Heat pump module diagnosis
A detailed diagnosis is feasible at the contractor level display (see page 111). This
display is only shown with "Contractor" access rights (see page 130).
Troubleshooting
Control unit diagnostics
(cont.)
5368 522 UAE
Service