Alpha CD25C Installation And Servicing Instructions page 5

2.8 FLUE LENGTHS
CD Easy-Flue 500 mm with terminal and 90° bend. A CD Easy-Flue 1000 mm with terminal and 90° bend is also available.
CD 750 mm and 1000 mm flue extensions are available.
Length of Flue Required:-
Rear Flue = wall thickness + 140 mm (includes terminal). This is without back frame, add 40 mm if the wall jig is used.
Side Flue = wall thickness + distance between wall and side of boiler + 225 mm (includes terminal)
Vertical Flue = distance from top of boiler side panel to required roof position minus 1 m for vertical terminal assembly
Maximum horizontal flue length = 12 m.
Maximum vertical flue length including terminal is 15 m.
Each additional CD 90° Bend is equivalent to 1.3 m of flue length.
Each CD 45° Bend is equivalent to 0.9 m of flue length.
The CD Vertical Flue terminal assembly is equivalent to 1 m of flue length.
2.9 AVAILABLE PUMP HEAD FOR CENTRAL HEATING
Output (50/30°C) Available pump head
kW Btu/h
metres
2.3
25.40 86 700
3.5
18.70 64 000
3.8
15.60 53 000
4.0
12.35 42 200
4.6
5.30 18 100
This information is based on 20°C system design temperature difference.
Note: For outputs upto 28 kW refer to Section 3.7.
2.10 ELECTRICAL CONNECTIONS
Note: This Appliance Must Be Earthed
An optional integral single channel Clock kit is available if required.
Note: Only use the Alpha single channel clock. Do not fit any two channel clocks.
Not Red Red Brown
Used Wire Wire Wire
5 4 3 2
Internal Clock Terminals
WARNING
1. Ensure wires are connected
correctly
2. Only fit the Alpha recommended
single channel clock. Other
clocks could cause damage.
Clock connections
Flow rate
20°C
feet litre/min
7.6 16.6
11.6 12.6
12.6 10.5
13.2 8.3
15.2 3.2
Blue
Wire
1
Fig. 1
20°C
gal/min
3.7
2.8
2.3
1.8
0.7
Boiler terminal block
Alpha CD25C/28C/35C - Technical Data
5