Converting The Appliance To Different Gas Types; Setting The Gas/Air Ratio - Benchmark ZWB 7-29 CC1 Installation And Servicing

7

Converting the appliance to different gas types

The setting is factory sealed at maximum. Adjustment to
the rated heat input and min. heat input is not neces-
sary.
Checking the gas supply pressure
B Check the gas supply pressure at the gas supply
pressure testing point.
Natural gas appliances must not be oper-
i
ated if the gas supply pressure is below
18 mbar or above 24 mbar.
LPG appliances must not be operated if
the supply pressure is below or above
37 mbar.
Natural gas
• Appliances for natural gas type G20 are factory set
to Wobbe-Index 15 kWh/m
pressure and sealed.
Conversion kits
For conversion
Model from ...
ZWB 7-29 N.G to L.P.G
ZWB 11-27 L.P.G to N.G
Table 16
• Instructions are sent with each conversion kit.
6 720 610 599 GB (03.02)
3
and 20 mbar supply
Order no.
7 710 149 048
7 710 239 084
Converting the appliance to different gas types
7.1

Setting the gas/air ratio

The gas/air ratio may only be adjusted on the
basis of a CO measurement at max. heat output
2
and min. heat output using an electronic tester.
B Switch off the appliance at the master switch (O).
B Remove the outer case (see page 15, refer to
fig. 13).
B Switch on the appliance at the master switch (I).
B Unscrew sealing plug from flue gas testing
point (234). Refer to fig. 42.
B Insert testing probe about 135 mm into the flue gas
testing point and seal testing point.
Fig. 42
B Press and hold
button until the display shows – –.
The button will light up.
6 720 610 332-32.1O
Fig. 43
B Turn the temperature control
shows 2.0 .
After a short delay, the current operating mode set-
ting will be displayed (0. = Normal mode).
6 720 610 332-60.1O
Fig. 44
until the display
31