Viessmann VITODENS 111-W Installation And Service Instructions Manual page 66

Troubleshooting
Repairs
(cont.)
Checking and cleaning the plate heat exchanger
Note
Drain the boiler on the heating water and
DHW sides.
A
2x
B
1. Undo plate heat exchanger A
(screws B) and pull out of the front.
2. Check the connections on the heat-
ing water and DHW side for contam-
ination and scaling; if required,
replace the plate heat exchanger.
66
3. Install in reverse order using new
gaskets.