101
Draining the boiler on the heating water side
A
Fig. 65
1.
Close the shut-off valves on the heating water side.
2.
Route hose at drain valve
A
into a suitable con-
tainer or drain outlet.
3.
Open drain valve
A
and drain the boiler as much
as required.
Checking the outside temperature sensor
X3
Fig. 66
Troubleshooting
Maintenance
(cont.)
5773 238 GB
Diagnosis