4
3. Technical Data
MAXIMUM AVAILABLE PUMP HEAD
BOILER OUTPUT HEAD MIN. FLOW RATE
kW
Metres L/min.
°C
6.9
5.2 9 11
24 1.8 22 15.5
28 1.8 22 18
Table 3
MECHANICAL SPECIFICATIONS 24Si II 28Si II
CENTRAL HEATING FLOW - COMPRESSION 22mm 22mm
RETURN - COMPRESSION 22mm 22mm
COLD WATER INLET - COMPRESSION 15mm 15mm
DOMESTIC WATER FLOW - COMPRESSION 15mm 15mm
GAS INLET
Rp
3
⁄
4
Rp
3
⁄
4
RELIEF VALVE DISCHARGE (PUSH-IN) 15mm 15mm
CASING HEIGHT 740mm 740mm
CASING WIDTH 400mm 440mm
CASING DEPTH 360mm 360mm
WEIGHT - LIFT 36kg 36kg
WEIGHT - PACKAGED
48kg 50kg
WEIGHT - DRY
39kg 40kg
Table 4
FLUE DETAILS
HORIZONTAL FLUE
G20 LPG
WALL HOLE DIAMETER EXTERNAL FIX mm
110 110
INTERNAL FIX mm
130 130
STANDARD FLUE MINIMUM LENGTH mm
275/*425 275/*425
MAXIMUM LENGTH mm 725 725
EXTENDED FLUE MAXIMUM LENGTH mm 4000 2500
FLUE ASSEMBLY DIAMETER mm 100 100
Table 2.
FLOW/RETURN
DIFFERENTIAL
* NOTE : Minimum uncut length
NOMINAL BOILER RATINGS (10 Minutes After Lighting)
BOILER ADJUSTED FOR G20 (Natural Gas)
OUTPUT INPUT (Net)
GAS RATE
kW
kW
m bar.
m
3
/h
8.1
9.2
0.7
0.97
28
30.7
13.1
3.25
BOILER ADJUSTED FOR G31 (Propane)
8.1
9.2
2.8
0.38
28
30.7
34.5
1.25
Table 1.
28Si II
BURNER
PRESSURE
NOMINAL BOILER RATINGS (10 Minutes After Lighting)
BOILER ADJUSTED FOR G20 (Natural Gas)
OUTPUT INPUT (Net)
GAS RATE
kW
kW
m bar.
m
3
/h
6.9
7.9
0.9
0.84
24
26.4
12.1
2.8
BOILER ADJUSTED FOR G31 (Propane)
6.9
7.9
3.1
0.32
24
26.4
35.0
1.08
Table 1.
24Si II
BURNER
PRESSURE
Natural Gas: Net Input = Gross Input x 0.901
LPG (Propane): Net Input = Gross Input x 0.922
NOTE:
With longer flue lengths, not using a restrictor, the minimum burner pressure will rise, naturally due to the flue, to 1.1mbar on G20
appliances only.