Repairs; Draining The Boiler On The Heating Water Side - Viessmann VITODENS 111-W Installation And Service Instructions Manual

Troubleshooting

Repairs

Draining the boiler on the heating water side

!
Please note
Risk of scalding
Residual water will escape when the boiler or
one of the following components is fitted or
removed:
■ Water-filled pipework
Circulation pumps
■
Plate heat exchanger
■
■ Components fitted in the heating water or
DHW circuit.
Water ingress can result in damage to other
components.
Protect the following components against
ingress of water:
Control unit (especially in the service position)
■
■ Electrical components
■ Plug-in connections
■ Electrical cables/leads
Only drain the boiler or heating system when the
boiler water or cylinder temperature has drop-
ped below 40 °C.
B A
C
Fig. 41
1. Switch on the control unit. Call up the actuator test
and put the diverter valve into its central position
(see "Actuator and sensor test").
2. Wait until the valve has moved into its central posi-
tion (approx. 5 s), then turn off the ON/OFF switch
" " on the control unit.
8
3. Route hose at drain valve
tainer or drain outlet.
92
A into a suitable con-
4. Close heating flow shut-off valve
return shut-off valve
C
5. Open drain valve . Drain the boiler as much as
A
necessary.
Note
Residual water will remain in the boiler.
and heating
B
.