Description Of Servicing Operations - Benchmark ZSBR 7-30 RD 430i Installation And Servicing Instructions

Maintenance
9.2

Description of servicing operations

The combustion performance must be checked before
and after any servicing work on the combustion and
burner components. Refer to section 8.2.
Checking the ionisation current,
Service Function 3.3
B Select Service Function 3.3. (See page 32 "Display-
ing Service Functions")
If the display shows 2 or 3, the ionisation current is OK.
If the display shows 0 or 1, the electrode assembly
(32.1, page 6) must be cleaned or replaced.
Primary Heat exchanger
There is a special accessory kit (no. 840) for cleaning
the heat exchanger, order no. 7 719 001 996.
B Check control pressure on the air - gas mixer unit at
max. rated heat output using an electronic manome-
ter.
Fig. 45
The heat exchanger should only be
i
cleaned if the control pressure is
2.2 mbar (depression) or less.
B Remove cleaning access cover (415, page 6) and
the metal plate below it, if present. Refer to fig. 2.
B Unscrew condensation trap and place suitable con-
tainer underneath. Refer to fig. 46.
38
B Remove the fan and the burner as described in the
Fig. 46
B Loosen any deposits in the heat exchanger from top
Fig. 47
6 720 610 332-69.1R
B Clean the heat exchanger from top to bottom using
Fig. 48
B Flush the heat exchanger from the top. Refer to
text headed "Burner" (see page 39).
to bottom using the cleaning blade. Refer to fig. 47.
6 720 610 332-73.1R
the brush. Refer to fig. 48.
fig. 49.
6 720 610 332-72.1R
6 720 610 332-74.1R
6 720 611 449 GB (03.11)