106
C
A
B
Fig. 74
1.
Shut off and drain the boiler on the heating water
and DHW sides.
2.
Release side fasteners and pivot control unit for-
ward.
3.
Remove the siphon (see page 42).
4.
Push thermal insulation panel
A
upwards and
remove.
5.
Undo two screws
B
and remove plate heat
exchanger
C
with insulation through the front.
6.
Check the connections on the heating water and
DHW side for contamination and scaling; if
required, replace the plate heat exchanger.
7.
Install in reverse order using new gaskets.
Checking the flue gas temperature sensor
The flue gas temperature sensor locks the boiler if the
permissible flue gas temperature is exceeded. After
the flue system has cooled down, press the reset but-
ton
R
to cancel the lock.
Troubleshooting
Maintenance
(cont.)
5773 238 GB
Diagnosis
