66
1.
Close the on-site boiler drain and fill valve.
2. Draining the heating water side
Connect the hose to the secondary circuit drain &
fill valve: See chapter "Internal components" on
page 65.
Open the secondary circuit drain & fill valve.
Checking the temperature sensors
For PCB locations in the heat pump: See page 64.
For sensor locations in the heat pump: See page 65.
Sensor
Test element
Connection
■
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)
■
Flow temperature sensor for cooling circuit: Heating
circuit without mixer A1/HC1 or separate cooling cir-
cuit SKK (F14)
■
Room temperature sensor, cooling circuit (F16)
■
Boiler water temperature sensor, external heat gener-
ator (F20)
■
Room temperature sensors for heating circuits
Viessmann NTC 10 k
Ω
(blue marking)
Controller and sensor PCB
■
Return temperature sensor, primary circuit (F3)
Viessmann Pt500A (green
marking)
Controller and sensor PCB
■
Flow temperature sensor for secondary circuit (T1)
■
Flow temperature sensor for secondary circuit, up-
stream of instantaneous heating water heater (T2)
■
Secondary circuit return temperature sensor (T3)
■
Suction gas temperature sensor (T4)
■
Flow temperature sensor for primary circuit (T5)
■
Hot gas temperature sensor (T6)
■
Liquid gas temperature sensor (T7)
NTC 10 k
Ω
(no marking)
EEV PCB
Maintenance
Draining heat pump on the secondary side
6153640
Service
