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3062880_0910
Changing the gas type / CO
2
settings
D) Completing the adjustments
• Shut down the boiler and close the test ports and hose
nipples; check for tightness.
C) Checking the CO
2
setting
• After completing the work, refit the casing cover and
check the CO
2
value with the appliance closed.
Observe the CO emissions whilst making
CO
2
adjustments.
The gas combination valve is incorrectly
adjusted, if the CO value is >200 ppm, when
the CO
2
value is correct.
Take the following steps:
Check the standard settings of the zero point and
throughput adjusting screws at the GCV and restrictor.
• Repeat the adjusting process from section A.
• The condensing boiler is correctly adjusted when the
CO
2
values correspond to those in the table below.
Appliance closed
(without casing) at
upper
load
Natural gas H
9.3% ± 0.3%
Appliance closed
(with casing) at
lower
load
Natural gas H
9.1% ± 0.3%
Fig.: Gas combination valve
MGK-170/210/250/300
MGK-130
Zero point adjusting screw, Tx40 Torx (under the
cover)
Gas throughput adjusting screw (under cover)
Allen screw 3 mm for the MGK-170 - MGK-300)
Slotted screw for the MGK-130