Checking Nozzle Pressure - Wolf CGU-2-18 Installation And Maintenance Instructions Manual

3. Checking and adjusting the nozzle pressure:
- The gas fired boiler must be switched OFF.
- Open the gas shut-off valve.
- Remove boiler casing cover and move the control unit
to the front.
- Undo the plug at the test nipple [2].
- (+) Connect the differential pressure tester with a hose
at test nipple [2].
- (-) Connect the differential pressure tester with a hose
at test port [3] of the combustion chamber casing (only
CGG-2(K)).
- Start the boiler by turning the heating water temperature
selector to position 8.
- Read off the nozzle pressure P
output) within 180 seconds of ignition (soft start phase
= minimum output).
- Turn the heating water temperature selector further to
the emissions test position [chimney symbol].
- Read off the nozzle pressure P
output) within the 15 minute test phase.
- Compare the actual values with those in the table.
- Close the plug again.
Gas pressures for gas throughput adjustment according to the nozzle pressure method
Gas fired boilers
(gas fired combi
boilers)
CGU-2(K) -18
CGU-2(K) -24
CGG-2(K) -18
CGG-2(K) -24
Table: Nozzle pressure table
36
Check nozzle pressure
(at minimum boiler
min
(at maximum boiler
max
Rated output P Rated thermal
in kW load
Q in kW
18.0
15.3
13.0
10.9
8.0
24.0
20.4
16.0
13.0
10.9
18.0
15.3
13.0
10.9
8.0
24.0
20.4
16.0
13.0
10.9
Nozzle pressure in mbar (1013 ±0.5 mbar; 15 °C)
Natural gas H
W = 45.7 MJ/m³
1
= 12.7 kWh/m³
20.2 12.7
17.3 9.5
14.8 7.1
12.5 5.2
8.8 3.2
26.5 12.9
22.5 9.4
18.1 6.3
14.9 4.4
12.0 3.1
19.7 15.9
16.7 11.4
14.2 8.8
12.0 6.3
8.5 3.3
26.5 16.8
22.5 12.2
17.7 7.5
14.0 4.8
11.7 3.4
[2]
[3]
LPG P
W = 70.7 MJ/m³
1
= 19.6 kWh/m³
26.7
20.0
14.8
10.7
5.8
25.4
18.7
12.3
8.5
6.0
36.0
25.9
19.3
14.1
7.5
35.8
26.1
15.9
10.0
7.3
3062347_0309