Baxi Combi 224 Installation And Service Manual page 59

Fig.58 Adjusting the gas valve
C
1
A
2
D
7696317 - 1 - 21032018
A Minimum rate (offset) adjustment screw.
B Maximum rate adjustment screw.
C Burner gas pressure outlet.
1
D Gas supply pressure outlet.
B
Important
The case front panel must be fitted when checking combustion.
2
Run the boiler for several minutes before checking the CO and CO
do this it is necessary to operate the boiler in Chimney sweep mode.
Ensure the boiler is at Maximum rate.
Insert the test probe in the flue sample point and allow the reading to
stabilise.
PN-0000527
See
Checking combustion - chimney sweep mode, page 48. If the
appliance cannot be operated on central heating for more than 10
minutes without reaching maximum temperature refer to
Combustion check on small heating systems, page 74.
See
Technical information - LPG, page 75 for details of LPG CO and
CO values
2
The CO at MAXIMUM rate should be 9% +0.4, –0.2. Alter the CO
2
necessary by adjusting the gas valve.
Use the Maximum rate adjustment screw (B) to alter the CO
clockwise (B1) to increase the CO
Important
Do not turn the adjustment screw more than 1/8 of a turn at a
time. Allow the analyser reading to settle before any further
adjustment.
Set the boiler to Minimum rate and check the CO
MINIMUM rate should be 8.5% +0.1, –0.4. Alter the CO
adjusting the gas valve.
Use the Minimum rate adjustment screw (A) to alter the CO
clockwise (A2) to increase the CO
the CO .
2
Check the combustion performance (CO/CO
than 0.004.
Important
If the CO
maximum rate again and adjusted if required. If the CO
maximum rate it must be rechecked at minimum rate and adjusted
if required.
Press the Chimney sweep button for 3 seconds to exit the function.
Refit the sampling point plug and ensure there is no leakage of
products.
or clockwise (B2) to reduce the CO
2
or anti-clockwise (A1) to decrease
2
is reset at minimum rate it must be rechecked at
2
10 Maintenance
. To
2
if
2
. Turn anti-
2
. The CO at
2 2
if necessary by
2
. Turn
2
ratio). This must be less
2
is reset at
2
59
.
2