Viessmann Vitocal 242-S Installation And Service Instructions Manual page 72

Maintenance
Draining secondary side heat pump
1. Close the on-site boiler drain & fill valve.
Checking the sensors
Sensor
Outside temperature sensor (F0)
■
Buffer temperature sensor (F4)
■
Cylinder temperature sensor (F6)
■
Flow temperature sensor, system (F13)
■
Flow temperature sensor, cooling circuit (di-
■
rect heating circuit A1/HC1 or separate cool-
ing circuit SKK) (F14)
Return temperature sensor, solar circuit (F23)
■
Room temperature sensors
■
Flow temperature sensor, secondary circuit
■
(F8)
Return temperature sensor, secondary circuit
■
(F9)
Flow temperature sensor, secondary circuit
■
upstream of instantaneous heating water
heater (LWT)
Liquid gas temperature sensor (IRT)
■
Temperature sensor, refrigerant inlet, evapo-
■
rator (OCT)
Temperature sensor, evaporator (OMT)
■
Temperature sensor, air intake, evaporator
■
(OAT)
Collector temperature sensor (F21)
■
Compressor head temperature sensor (hot
■
gas) (CTT)
72
2. Drain the heat pump at the secondary circuit fill &
drain valve (see chapter "Overview of internal com-
ponents: Internal unit").
Test ele- Installed location
ment
NTC 10 k Internal unit (see
Ω
page 67)
Pt500A Internal unit (see
(PTC) page 67)
NTC 10 k Internal unit (see
Ω
page 67)
NTC 10 k External unit (see
Ω
page 68)
NTC 20 k Internal unit (see
Ω
page 67)
NTC 50 k External unit (see
Ω
page 68)
Connection
Controller and sensor
PCB (see page 33)
Controller and sensor
PCB (see page 33)
AVI PCB (see service
instructions for
Vitotronic 200,
type WO1C)
Refrigerant circuit con-
troller (observe label on
the external unit)
Controller and sensor
PCB (see page 33)
Refrigerant circuit con-
troller (observe label on
the external unit)