92
Draining secondary side heat pump
1.
Close the on-site boiler drain & fill
valve.
2.
Drain the heat pump at the secondary
circuit fill & drain valve (see chapter
"Overview of internal components:
Internal unit").
Checking the sensors
Sensor
Captur-
ing ele-
ment
Installed loca-
tion
Connection
■ Outside temperature sensor (F0)
■ Flow temperature sensor, cooling
circuit (direct heating circuit A1/
HC1 or separate cooling circuit
SKK) (F14)
■ Room temperature sensors
Ni 500
Internal unit (see
page 87)
Controller and
sensor PCB (see
page 50)
■ Buffer temperature sensor (F4)
■ Cylinder temperature sensor, top
(F6) and bottom (F7)
■ Flow temperature sensor, system
(F13)
■ Boiler water temperature sensor,
external heat source (F20)
Pt 500
■ Temperature sensor, compres-
sor head (CTT)
NTC
50 k
Ω
External unit
(see page 88)
Refrigerant circuit
control (observe
label on the exter-
nal unit)
■ Flow temperature sensor, secon-
dary circuit upstream of instanta-
neous heating water heater
(LWT)
■ Liquid gas temperature sensor
(IRT)
NTC
10 k
Ω
Internal unit (see
page 39)
AVI PCB (see
page 50)
■ Temperature sensor, refrigerant
inlet, evaporator (OCT)
■ Temperature sensor, evaporator
(OMT)
■ Temperature sensor, air intake,
evaporator (OAT)
External unit
(see page 88)
Refrigerant circuit
control (observe
label on the exter-
nal unit)
Troubleshooting
Repairs
(cont.)
5601 429 GB
