Initial start-up
2
Installation and maintenance instructions for wall-mounted condensing gas boiler 600 - 28C • 01/2004
29
Subject to modifications resulting from technical improvements!
Boulter Buderus Ltd. • http://www.boulter-boilers.com
2.1.8
Checking the gas/air ratio and adjust as required
z
Turn mains power switch "
0
" and make sure that the boiler
is not in chimney sweep mode.
z
Remove the casing of the boiler.
z
Shut the gas shutoff valve underneath the boiler (see
fig. 42, item 1).
z
Open at least two radiators.
z
Open the top measuring nipple (see fig. 44, item 1) with
two turns.
z
Set the pressure gauge to "
0
".
z
Connect a tube from the "+" side of the pressure gauge to
burner-pressure testing nipple (see fig. 44, item 2)
z
Open the gas shutoff valve (see fig. 42, item 2).
z
Set the mains switch to "
1
".
z
Set the boiler in service mode by pressing the chimney
sweep button until a non-blinking LED appears in the lower
right hand corner of the display.
z
Press the chimney sweep button and the service button at
the same time, until "
L--
" appears in the display.
z
Adjust the capacity to "
L25
" by pressing the reset button.
z
The optimum gas/air ratio is - 5 Pa (-0.05 mbar).
The pressure difference should be between -10 and 0 Pa
(see fig. 45).
If this is not the case then adjustment is needed:
z
Remove the safety screw with a flat head screwdriver
(fig. 46, item 1).
z
Adjust the adjustment screw of the burner pressure to the
correct gas/air ratio using a (4 mm) socket head wrench
and by referring to fig. 45.
z
Replace the safety screw.
z
Set mains power switch to "
0
".
z
Shut the gas shutoff valve (see fig. 42, item 1).
z
Remove the tube from from the burner-pressure testing
nipple.
z
Tighten the screw on the burner-pressure testing nipple.
z
Open the gas shutoff valve (see fig. 42, item 2).
z
Turn the mains power switch to "
1
".
z
Set the boiler in service mode by pressing the chimney
sweep button, until a non-blinking LED appears in the
lower right hand corner of the display.
z
Check the testing nipples for gas tightness.
z
Turn off the boiler again by pressing the mains power
switch to "
0
".
z
Turn the boiler on by setting the mains power switch to "
1
".
fig. 44 Check the gas/air ratio
fig. 45 Pressure difference at gas/air at "L25"
wrong
wrong
correct
leftturn
rightturn
-15
-10
-5
0
5 (Pa)
-0.15
-0.10
-0.05
0.00
0.05 (mbar)
fig. 46 Idjust gas/air ratio
CAUTION
Check the test nipples for gas tightness.
