Dhw Cylinder Drain & Fill Valve Positions - Viessmann VITOCAL 222-S Installation And Service Instructions Manual

Overview of internal components: Internal unit
Secondary circuit air vent valve
H
Pressure sensor (ICT) for determining conden-
K
sation temperature in condenser
DHW cylinder drain & fill valve positions
Fig. 58
Closed
A
Open to drain the internal DHW line
B
Open to drain or fill the cylinder
C
Overview of internal components: External unit
Danger
Contact with 'live' components can lead to seri-
ous injury from electric current. Some compo-
nents on PCBs remain 'live' even after the
power supply has been switched off.
■ When working on the external unit, isolate the
system from the power supply, e.g. at a sepa-
rate MCB/fuse or a mains isolator. Check the
system is no longer 'live' and safeguard
against reconnection.
■ Prior to working on the appliance, wait at
least 4 min until the voltage has completely
dropped out.
(cont.)
A
B
C
Maintenance
69