Draining Heat Pump On The Secondary Side - Viessmann Vitocal 300-A Series Installation And Service Instructions For Contractors

Maintenance

Draining heat pump on the secondary side

1. Close the on-site boiler drain & fill valve.
Checking the temperature sensors
■ For sensor connections to the controller and sensor
PCB: See page 27.
For the position of the sensors in the heat pump: See
■
Fig. 50 on page 67.
Sensor
Outside temperature sensor (F0)
■
Buffer temperature sensor (F4)
■
Cylinder temperature sensor, top (F6)
■
Cylinder temperature sensor, bottom (F7)
■
Flow temperature sensor, heating circuit with mixer M2/HC2 (F12)
■
System flow temperature sensor (F13)
■
Cooling circuit flow temperature sensor (heating circuit without mixer A1/HC1 or sepa-
■
rate cooling circuit SKK) (F14)
Room temperature sensor for separate cooling circuit (F16)
■
Boiler water temperature sensor, external heat generator (F20)
■
Room temperature sensors
■
Sensors in the refrigerant circuit
■
Secondary circuit flow temperature sensor (F8)
■
Return temperature, secondary circuit (X25.11/X25.12)
■
Air intake temperature sensor (X25.1/X25.2)
■
Air discharge temperature sensor (X25.3/X25.4)
■
68
2. Drain the heat pump at the drain valve: See Fig. 50
on page 67.
Test element
NTC 10 k
Ω
Pt500A