Viessmann VITODENS 050-W Installation And Service Instructions Manual page 44

Commissioning, inspection, maintenance
Further details regarding the individual steps
Note
Discolouration on the heat exchanger
surface is a normal sign of use. It has
no bearing on the function and service
life of the heat exchanger.
A
44
The use of chemical cleaning agents is
not required.
1. Use a vacuum cleaner to remove
combustion residues from heating
surface A of the heat exchanger.
2. Flush heating surface A with
water.
3. Check condensate drain and clean
trap. See the following chapter.
4. Flush the heating surface again
with water. This will also fill the trap
with water.
(cont.)