Viessmann Vitocal 300-G Installation And Service Instructions Manual page 131

Control unit diagnostics
ID Characteristics and effects of system/control unit
30 The heat pump will not start.
31
38
39
40 Mixer heating circuit M2 is closed.
48
41 Mixer heating circuit M3 is closed.
49
44 Cooling mode" natural cooling" without regulating the flow. Control via
4C external humidity sensor and frost stat.
50 Use of the lower cylinder temperature sensor. DHW heating and heating
58 by the solar heating system will be blocked if only one sensor is avail-
able or both sensors are faulty.
52 Use of the upper cylinder temperature sensor. DHW heating and heat-
5A ing by the solar heating system will be blocked if only one sensor is
available or both sensors are faulty.
60 The cylinder is heated once every hour. Shutdown through the return
68 temperature sensor.
63 External heat source is blocked. The instantaneous heating water hea-
6B ter (if installed) is enabled.
70 No frost protection mode via room temperature sensor
71 No room temperature hook-up
72 No room temperature control
78
79
7A
D6 The heat pump will not start
Pow- The power-OFF (triggered by the power supply utility) is enabled longer
er- than 12 hours.
OFF
Heat pump module diagnosis
A detailed diagnosis is feasible at the contractor level display (see page 117).
This display is only shown with "Contractor" access rights (see page 136).
Access
Main menu
Device settings
Contractor level
(cont.)
Further menu items
Diagnosis heat pump module
Troubleshooting
131