Viessmann Vitocal 222-S Installation And Service Instructions For Contractors page 89

Overview of internal components: Outdoor unit
Refrigerant receiver
O
Electronic expansion valve
P
Schrader valve, high pressure side
R
Refrigerant circuit controller temperature sensor
S
(T2)
Draining the heat pump on the secondary side
Fig. 75
Drain and fill valve, secondary side
A
B Drain and fill valve, DHW side
Checking the temperature sensors
Connection to the indoor unit
Temperature sensors are connected to the controller
and sensor PCB: See page 44.
Temperature sensor
Outside temperature sensor (F0)
■
Buffer temperature sensor (F4)
■
Cylinder temperature sensor, top (F6)
■
Flow temperature sensor, heating circuit with mixer M2/HC2 (F12)
■
System flow temperature sensor (F13)
■
Cooling circuit flow temperature sensor (direct heating circuit A1/HC1 or separate cool-
■
ing circuit SKK) (F14)
Room temperature sensors
■
Secondary circuit flow temperature sensor (F8)
■
Secondary circuit return temperature sensor (F9)
■
Secondary circuit flow temperature sensor upstream of instantaneous heating water
■
heater (F3)
Reversible suction gas temperature sensor (F24)
■
Liquid gas temperature sensor (F25)
■
(cont.)
1. Close the on-site boiler drain and fill valve.
2. Draining the heating water side
Connect the hose to the drain and fill valve of the
secondary circuit.
Open the secondary circuit drain and fill valve.
3. Draining the DHW side
See chapter "Draining the appliance on the DHW
side", page 69.
A
B
Maintenance
Test element
NTC 10 k
Ω
Pt500A
(PTC)
89