Viessmann FB2A Installation And Service Instructions For Contractors page 94

Troubleshooting
Repairs
(cont.)
Draining the boiler on the heating water side
1. Close the shut-off valves on the heat-
ing water side.
2. Route hose at drain valve A into a
suitable container or drain outlet.
94
3. Open drain valve A and drain the
boiler as much as required.