Wolf CGB-75 Instructions Manual page 67

Adjusting the gas:air connection
Carry out the adjustments in the following order: At the factory, the gas combination valve has been adjusted for
NB
the gas type stated on the type plate. Only adjust the gas combination valve after the system has been changed
to a different gas type or when servicing.
If too little heat is drawn off, open some radiator valves.
A) CO adjustment at the upper load (emissions test
2
mode) for natural gas
- Pivot the control unit flap down.
Unlock the casing cover with the l.h. and r.h. turnbuckles.
Release the bottom of the casing cover and unhook at the
top.
- Remove the screw from the l.h. "Flue gas" test port.
- Insert the test probe of the CO
test port (approx. 120 mm).
- Turn the temperature selector to "Emissions test"
(Illuminated signal ring as status indicator flashes yellow.)
- Ensure that the boiler is not limited electronically.
- Check the CO content at full load, and compare the actual
2
values with those in the table below.
- Correct the CO adjustment (if required) using the gas flow
2
adjusting screw on the gas combination valve in accordance
with the table.
The upper load cannot be adjusted for LPG.
- turn clockwise - lowers CO
- turn anti-clockwise - raises CO
Appliance open
at upper load
Natural gas H
8.6% ± 0.2%
- Terminate the emissions test mode by turning the tempera-
ture selector back into its original position.
3061741_201712.indd
CO adjustment
2
tester into the "Flue gas"
2
.
content
2
content
2
LPG P (check)
10.1% ± 0.2%
l.h. turnbuckle
Figure: Opening the turnbuckle
Figure: Gas combination valve
Figure: Flue gas test with an open boiler
r.h. turnbuckle
Gas flow adjusting
screw
(only for natural
gas)
Test port
"Flue gas"
67