Checking The Sensors - Viessmann VITOCAL 350-G Series Installation And Service Instructions For Contractors

Maintenance
Draining the heat pump on the primary/secondary side
1. Shut off the connection to the heating network.

Checking the sensors

For sensor connections to the controller and sensor
PCB: See page 33.
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 (direct heating circuit A1/HC1 or separate cool-
■
ing circuit SKK) (F14)
Room temperature sensor, cooling circuit (F16)
■
Boiler water temperature sensor, external heat generator (F20)
■
Room temperature sensors for heating circuits
■
Flow temperature sensor, primary circuit (F2)
■
Return temperature sensor, primary circuit (F3)
■
Flow temperature sensor, secondary circuit, in a 2-stage heat pump for heat pump
■
stage 1 (F8)
Return temperature sensor, secondary circuit, in a 2-stage heat pump for heat pump
■
stage 1 (F9)
Secondary circuit return temperature sensor for heat pump stage 2 (F18)
■
Secondary circuit flow temperature sensor for heat pump stage 2 (F27)
■
Sensors in the refrigerant circuit
■
66
2. Drain the heat pump at the primary/secondary side
drain valve: See page 65.
For the position of the sensors in the heat pump: See
diagram on page 65.
Test element
NTC 10 k
Ω
Pt500A
(PTC)