Viessmann FB2B Installation And Service Instructions Manual page 122

Troubleshooting
Repairs
(cont.)
Checking the plate heat exchanger
Note
Drain the boiler on its heating water and DHW side.
During removal, small amounts of water may trickle out and escape from the plate
heat exchanger.
1. Shut off and drain the boiler on its
heating water and DHW side.
2. Release the side closures and pivot
the control unit forward.
3. Remove the siphon (see page 29).
122
B A
4. Push insulating mat A upwards and
remove.
5. Undo two screws B and pull out
plate heat exchanger C with insula-
tion to the front.
C