Viessmann Vitodens 222-F B2TA Installation And Service Instructions Manual page 143

Repair
(cont.)
Checking the plate heat exchanger
Note
Drain the boiler on its heating water and
DHW side.
1. Shut off and drain the boiler on the
heating water and DHW sides.
2. Release the side closures and pivot
the control unit forward.
3. Remove the siphon (see page 54).
During disassembly and once removed,
small amounts of water may escape from
the plate heat exchanger.
4. Push thermal insulation panel A
upwards and remove.
5. Undo two screws B and pull out
plate heat exchanger C through the
front.
Troubleshooting
143