Draining The Boiler On The Dhw Side - Viessmann FB2A Installation And Service Instructions For Contractors

Commissioning, inspection, maintenance
Further details regarding the individual steps

Draining the boiler on the DHW side

42
1. Connect hose to drain valve and
route into a suitable container or drain
outlet.
Note
Ensure adequate ventilation in the
DHW pipework.
2. Turn drain valve from lever position
A to lever position B or C as
required.
■ Lever position B: Drain heating
system excluding cylinder via the
cold water connection.
■ Lever position C: Drain heating
system and cylinder via the DHW
connection. Cold water connection
remains filled.
(cont.)