SERVICING AND SPARES
6 720 815 725 (2015/05)
40
▶ Press and HOLD the Performance test button (J) for 10 seconds and
set Central Heating temperature to maximum.
– The Performance test button will illuminate continually.
– The boiler will stay in this mode for 15 minutes unless the
Performance test button is pressed again.
▶ Pull the cover off and connect a manometer to the fan pressure test
point.
▶ After measurement replace test point cover.
Fig. 64 Fan pressure readings
• Pressures readings in the black area will indicate that the heat
exchanger requires attention/cleaning.
• There is a special accessory kit available specifically designed for
cleaning the heat exchanger.
Part number 7 719 001 996.
Fig. 65 Fan pressure test point
6.1.4
TO CLEAN THE HEAT EXCHANGER
▶ Remove outer case and base panel and isolate the appliance from
power.
1. Remove cleaning access cover (B), seal (C) and metal plate (D)
securing it, if present.
Fig. 66 Cleaning heat exchanger
2. Loosen any deposits in the heat exchanger from top to bottom using
the cleaning blade.
6720803599-01.1W
o
FAN PRESSURE TEST
Clean the Heat Ex.
Heat Ex. ok
NG Boilers
0
-6
-5
-4
-3
-2
-1
-8
-7
mbar
38 CDi:
42 CDi:
29 CDi:
34 CDi:
- 4.4
- 4.8
- 3.9
- 5.3
LPG Boilers
0
-6
-5
-4
-3
-2
-1
-8
-7
mbar
38 CDi:
42 CDi:
29 CDi:
34 CDi:
- 4.4
- 4.8
- 3.9
- 5.3
3.
6 720 815 725-22.1O
NOTICE:
Air/Gas ratio
▶ After servicing the CO/CO
2
must be checked using
the procedure in the section “Setting the air/gas
ratio” on page 42.
▶ The setting of the air/gas ratio must be carried out by
a competent person.
Setting the air/gas ratio must not be attempted
unless the person carrying out the operation is
equipped with a combustion analyser conforming to
BS 7927 and is competent in its use.
B
C
D
1.
6720803599-11.1Wo
2.
6720803599-03.1Wo
