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

Troubleshooting
Repairs
(cont.)
6. Check the DHW side for scaling and
if required clean or replace the plate
heat exchanger.
7. Check the heating water side for con-
tamination and if required clean or
replace the plate heat exchanger.
Checking the fuse
1. Switch off the power.
2. Open control unit casing (see
page 15).
3. Check fuse F4.
50
8. Install in reverse order with new gas-
kets.
Note
During installation, ensure that fixing
holes are aligned and gaskets seated
correctly. Install the plate heat
exchanger with the correct orienta-
tion.
F4