Viessmann Vitodens 100-W WB1B Installation And Service Instructions Manual page 46

Troubleshooting
Repairs
(cont.)
5. Remove two screws C from the
plate-type heat exchanger and
remove plate-type heat exchanger
D with gaskets.
Note
During removal, small amounts of
water may trickle out and escape
from the removed plate-type heat
exchanger.
6. Check the DHW side for scaling
and, if required, clean or replace
the plate-type heat exchanger.
Checking the fuse
1. Switch OFF the power.
2. Open control unit casing (see
page 13).
46
7. Check the heating water side for
contamination and, if required,
clean or replace the plate-type heat
exchanger.
8. Install in reverse order with new
gaskets.
Note
Ensure that fixing holes and seals
are aligned. Install the heat plate
exchanger the correct way round.
3. Check fuse F4.