Checking Sensors - Viessmann VITOCAL 300-G Installation And Service Instructions Manual

Troubleshooting
Repairs
(cont.)
O Primary circuit return temperature
sensor (heat pump brine outlet)
P Hot gas temperature sensor
Q Schrader high pressure valve
Draining the heat pump on the primary/secondary side
1. Close on-site drain & fill valve.

Checking sensors

For sensor connections to the controller
and sensor PCB, see page 228.
Temperature sensors type Ni 500
640
600
560
520
480
440
400
-40 -20 0
Temperature in °C
166
40
20 60
R Low pressure sensor EEV
S Safety high pressure switch
T Schrader low pressure valve
U Evaporator
2. Drain heat pump at drain valve on pri-
mary/secondary side (see
page 165).
For the position of the sensors in the heat
pump, see figure on page 165.
Capturing element: "Ni 500"
■ Outside temperature sensor (F0)
■ Flow temperature sensor, heating cir-
cuit M2 (F12)
■ Flow temperature sensor, separate
cooling circuit
■ Room temperature sensors