Viessmann Vitocal 300-G Installation And Service Instructions For Contractors page 118

Troubleshooting
Repairs
(cont.)
Draining the heat pump on the primary/secondary side
1. Close the on-site drain & fill valve.
Checking sensors
Sensor connections to the controller and
sensor PCB.
Temperature sensors type Ni 500
640
600
560
520
480
440
400
-40 -20 0
Temperature in °C
118
40
20 60
2. Drain heat pump at drain valve on pri-
mary/secondary side (see
page 117).
For the position of the sensors in the heat
pump, see diagram on page 117.
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