97
A
Fig. 55
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. 56
Troubleshooting
Maintenance
(cont.)
5778741
Diagnosis