Technical data

PERFORMANCE SPECIFICATIONS 24Si II 28Si II
PRIMARY WATER CAPACITY litres 2.0
IP RATING (WHOLE OF BOILER) IP 20
MAXIMUM MAINS INLET PRESSURE bar 10
MINIMUM MAINS INLET PRESSURE (WORKING) FOR MAXIMUM FLOW bar 1.0
MINIMUM MAINS INLET PRESSURE (WORKING) FOR OPERATION bar 0.25
DOMESTIC HOT WATER TEMPERATURE RANGE °C 40 - 60
MAXIMUM CENTRAL HEATING FLOW TEMPERATURE °C 82 (nom)
MAXIMUM CENTRAL HEATING SYSTEM SET PRESSURE bar 2.65
MINIMUM CENTRAL HEATING SYSTEM PRESSURE bar 0.5
OUTPUT TO CENTRAL HEATING & DHW kw NATURAL GAS (G20) 24 28
LPG - PROPANE (G31) 24 28
DOMESTIC HOT WATER SPECIFIC RATE - 30°C RISE l/min 11.5 13.5
MAXIMUM DOMESTIC HOT WATER FLOW RATE - 40°C RISE l/min 8.5 10
FLUE GAS MASS FLOW RATE 14.9 17.4
FLUE GAS TEMPERATURE °C 146.0
NOx CLASSIFICATION FOR BOTH 24 & 28Si II Class 3
SEDBUK NUMBER 78.0 78.2
SEDBUK NUMBER LPG 80.5 80
SEDBUK BAND* D D
5
GAS SUPPLY SYSTEM - BASED ON NG (G20)
TOTAL LENGTH OF GAS SUPPLY PIPE (COPPER) metres
3 6 9 12
GAS DISCHARGE RATE - PRESSURE DROP mbar. m
3
/h PIPE DIAMETER mm
8.7 5.8 4.6 3.9 22
18.0 12.0 9.4 8.0 28
Table 7
CLEARANCES (mm)
INSTALLATION SERVICE UNVENTILATED COMPARTMENT
ABOVE FLUE ELBOW 30 30 150
IN FRONT OF APPLIANCE 600 600 *240
BENEATH APPLIANCE 200 200 200
RIGHT AND LEFT HAND SIDE 10 10 80
Table 8
SYSTEM CAPACITY
TOTAL SYSTEM VOLUME litres
INITIAL INITIAL CHARGE PRESSURE bar
PRESSURE bar 0.5 1.0 1.5
1.0 57 75 N/A
1.5 31 42 52
Table 9
Refer to Section 6. * Front clearance is to a removable panel (eg. door)
DOMESTIC HOT WATER TEMPERATURE RISE
DISCHARGE RATE l/min 7 8 9 10
TEMPERATURE RISE °C 24kw 49 43 38 34
TEMPERATURE RISE °C 28kw 57 50 45 40
Table 6
Table 5
* The value is used in the UK Government Standard Assessment Procedure [SAP] for the energy rating of dwellings. The test data from
which it has been calculated have been certified by the GASTEC notified body.