Worcester 28Si User Manual

The data plate is fixed to the inner casing cover.
4
3. Technical Data
MAXIMUM AVAILABLE PUMP HEAD
BOILER OUTPUT HEAD MIN. FLOW RATE
kW Metres L/min. °C
8.5 5.9 11.0 11
25 2.0 30.5 12
28 2.0 30.5 13
Table 3
FLUE DETAILS
HORIZONTAL FLUE mm
WALL HOLE DIAMETER EXTERNAL FIX 110
INTERNAL FIX 150
STANDARD FLUE MINIMUM LENGTH 330/425 *
MAXIMUM LENGTH 725
EXTENDED FLUE MAXIMUM LENGTH 2975
FLUE ASSEMBLY DIAMETER 100
Table 2.
FLOW/RETURN
DIFFERENTIAL
* NOTE : Flue lengths between 330 and 425mm require the flue to be cut
MECHANICAL SPECIFICATIONS
CENTRAL HEATING FLOW - COMPRESSION 22mm
RETURN - COMPRESSION 22mm
COLD WATER INLET - COMPRESSION 15mm
DOMESTIC WATER FLOW - COMPRESSION 15mm
GAS INLET Rp
3
⁄4
RELIEF VALVE DISCHARGE (PUSH FIT) 15mm
CASING HEIGHT 800mm
CASING WIDTH 440mm
CASING DEPTH 360mm
WEIGHT - LIFT 42.3kg
WEIGHT - UNPACKED 45.8kg
WEIGHT - PACKAGED 52kg
Table 4
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
8.5 10.5 0.7 1.12
28.0 31.1 14.1 3.38
BOILER ADJUSTED FOR G31 (Propane)
8.5 10.5 2.3 0.42
28.0 31.1 35.5 1.25
Table 1. 28Si
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
8.5 10.5 0.7 1.12
25.0 27.8 11.5 2.98
BOILER ADJUSTED FOR G31 (Propane)
8.5 10.5 4.2 0.42
25.0 27.8 35.7 1.12
Table 1. 25Si
BURNER
PRESSURE
Natural Gas: Net Input = Gross Input x 0.901 LPG (Propane): Net Input = Gross Input x 0.922

Worcester 28Si Specifications

General

Model	28Si
Output	28kW
Efficiency Rating	A
ErP Rating	A
Flow Rate	11.4 l/min
Water Pressure	3 bar
Max Gas Rate	2.8 m3/h