Inlet Gas Pressure; Checking And Adjusting The Gas/Air Ratio - Buderus Logamax plus GB142-24 Installation Instructions Manual

Boiler Type of gas
capacity supply
No CO
inch
24 kW Natural gas 0.175
LPG P 0.132
30 kW Natural gas 0.175
LPG P 0.132
45 kW Natural gas 0.213
LPG P 0.163
60 kW Natural gas 0.295
LPG P 0.213
Table 5 Gas orifice diameter
8.7

Inlet gas pressure

▶ Connect the pressure gauge connection hose ( fig. 36, [2]) to the
testing nipple ( fig. 36, [1]).
Fig. 36 Measuring the inlet gas pressure
[1] Testing nipple
[2] Pressure gauge connection hose
▶ Slowly open the gas shut-off valve.
The boiler and its individual shutoff valve must be disconnected from the
gas supply piping system during any pressure testing of that system at
test pressures in excess of ½ psi (3.5 kPa).
The boiler must be isolated from the gas supply piping system by closing
its individual manual shutoff valve during any pressure testing of the gas
supply piping system at test pressures equal to or less than ½ psi
(3.5 kPa).
▶ Briefly press on the control panel cover to open it.
Fig. 37 Opening the control panel
Logamax plus GB142-24/30/45/60 – 6720820104 (2017/05)
Gas orifice diameter
Altitude 0-10,200 ft
-correction Altitude
2
4,001-10,200 ft
with CO -correction
2
mm inch mm
4.45 0.179 4.55
3.35 0.134 3.40
4.45 0.177 4.50
3.35 0.134 3.40
5.40 0.219 5.55
4.15 0.163 4.15
7.50 0.301 7.65
5.40 0.215 5.45
1
2
72150200-35.1TD
72150200-36.1TD
▶ Switch on the heating system by setting the main switch to position
a
"1" ( chapter 9 "BC10 basic controller", page 25).
d
▶ Press the "Chimney Sweep"
2 seconds) until the display shows a decimal point.
▶ Measure the gas connection pressure as soon as the "Burner" LED
g
lights and enter this value in the start-up report.
The inlet gas pressure must be:
• for natural gas - min. 3.5 to 10.5 inch W.C (8.7 to 26.1 mbar),
nominal supply pressure 7.0 inch W.C. (17,4 mbar)
• for LPG - min. 8.0 to 13.0 inch W.C. (19.9 to 32.3 mbar), nominal
supply pressure 11.0 inch W.C. (27.4 mbar).
▶ Repeatedly press the "Service"
indication is displayed.
d
▶ Press the "Chimney Sweep"
procedure.
▶ Close the gas shut-off valve.
▶ Remove the connection hose again and tighten the screw plug on the
testing nipple.
▶ Open the gas shut-off valve again.
CAUTION:
▶ Contact the relevant gas utility company if the
required inlet gas pressure is not available.
▶ Install a gas pressure regulator before the gas burner
fitting if the supply pressure is too high.
8.8

Checking and adjusting the gas/air ratio

▶ Switch off the heating system using the main switch b.
▶ Loosen the screw plug on the measuring nipple for the burner
pressure by 2 rotations ( fig. 38, [1]).
Fig. 38 Checking the gas/air ratio
[1] Burner pressure measuring nipple
[2] Pressure gauge connection hose
▶ Set the pressure gauge to zero.
▶ Use a hose to connect the plus terminal of the pressure gauge to the
burner pressure measuring nipple ( fig. 38, [1]).
▶ Switch on the heating system using the main switch
▶ Press the "Chimney Sweep" d button and hold it (for approx. two
seconds) until the display shows the decimal point.
▶ Press and hold the "Chimney Sweep" d and "Service"
(for approx. five seconds) until the display shows "Lxx" (e. g. L80).
8
Start-up procedure
button and hold it (for approx.
e
button until the temperature
button to end the measurement
1
2
72150200-51.1TD
a
.
e
buttons
23