Viessmann Vitocal 242-S Installation And Service Instructions Manual page 105

Repairs
(cont.)
Temperature sensors in external unit (no marking)
Type NTC 10 kΩ
1000
100
10
1
0.1
-30 -20 -10 0 10 20 30 40 50 60 70 80 90 100
Temperature in °C
Type NTC 50 kΩ
1000
100
10
1
0.1
-30 -20 -10 0 10 20 30 40 50 60 70 80 90 100
Temperature in °C
Checking fuses
For fuse locations, see from page 49.
■ Fuse F1 is located on the mains ter-
minal of the heat pump control unit.
■ Fuse F3 is located on the main PCB.
■ Fuse F101 is located on the AVI PCB.
Fuses F1 and F3:
■ 6.3 AH (slow), 250 V~
■ Max. power loss ≤ 2.5 W
Fuse F101:
■ 1.0 AL (slow)
■ Max. power loss ≤ 2.5 W
Troubleshooting
105