Viessmann Vitocal 300-G Installation And Service Instructions Manual page 125

Repairs
(cont.)
Temperature sensors type Pt 500
860
780
700
620
540
460
-20 20 60 100
Temperature in °C
Checking the fuse
Fuse locations (see page 72):
■ Fuse F1 is located on the cross con-
nect PCB.
■ Fuse F3 is located on the main PCB.
Fuse F1 and F3:
■ 6.3 A (slow), 250 V~
■ Max. power loss ≤ 2.5 W
Appliance too noisy
Possible causes:
■ Transport locking bracket not
removed: See page 64.
■ Hose outlets in diaphragm grommets
not watertight: See page 104.
■ Control unit door not tightly sealed:
See page 121.
Capturing element "Pt 500"
■ System flow temperature sensor (F13)
■ Buffer temperature sensor (F4)
■ Cylinder temperature sensor (F6)
■ Flow/return temperature sensor, sec-
ondary circuit (F8/F9)
■ All sensors inside the heat pump
■ Boiler temperature sensor, external
heat source
140 180
Troubleshooting
Danger
Contact with 'live' components
can lead to severe injury from
electric current.
Before working on the equip-
ment, always ensure that the
power circuit is also at zero
volt.
Removing the fuse does not
switch the power circuit to zero
volt.
125