Viessmann Vitopend 100-W Installation And Service Instructions Manual page 39

Repairs
(cont.)
E Heating water flow
F Heating water return
Check the connections on the DHW side
for scale build-up and the connections on
the heating water side for contamination.
Clean or replace the plate heat
exchanger if required.
Replacing the plate heat exchanger
1. Push stepper motor A slightly
upwards.
45°
G Cold water
H DHW
2. Turn the stepper motor adaptor B
with stepper motor A anti-clockwise
by 1/8 of a turn and remove.
3. Remove two screws C from the
plate heat exchanger and remove
plate heat exchanger D with gas-
kets.
Troubleshooting
39