Venting The Boiler - Viessmann VITOLADENS 300-C Service Instructions Manual

Commissioning, inspection, maintenance
Further details regarding the individual steps
6. Close boiler fill valve C.

Venting the boiler

1. Close the shut-off valves on the
heating water side.
2. Remove front insulation shell A (if
already fitted).
3. Connect the drain hose on air vent
valve B with a drain.
8
(cont.)
4. Open valves B and C and vent
using mains pressure until no more
air noise is audible.
5. Close valves B and C and open
the heating water shut-off valves.