Viessmann VITODENS 100-W Installation And Service Instructions Manual page 50

Troubleshooting
Repairs
(cont.)
Serial no. Flow rate
(Type l/min
plate)
7499438
7499440
Checking or replacing the plate heat exchanger (gas condensing
combi boiler)
B
C Heating water flow
D Heating water return
1. Shut off and drain the boiler on the
heating water and the DHW side.
50
Colour
8 White
10 Black
C
F
A
Serial no. Flow rate
(Type l/min
plate)
7499443
7499447
B
E Cold water
F DHW
2. Pivot down control unit
Colour
12 Red
14 Brown
D
E