Viessmann Vitodens 100 Series Installation And Service Instructions Manual page 80

Troubleshooting
Repairs
(cont.)
4. Check the connections on the DHW
side for scaling; clean or replace
the plate heat exchanger if
required.
5. Check the connections on the heat-
ing water side for contamination;
clean or replace the plate heat
exchanger if required.
Checking the fuse
1. Switch OFF the power supply.
2. Open the control unit enclosure
(see page 25).
80
6. Install in reverse order using new
gaskets.
Note
During installation, ensure the fixing
holes are aligned and the gaskets
are seated correctly. Fit the plate
heat exchanger the right way
round.
F1
3. Check fuse F1.