Alpha CD25C Installation And Servicing Instructions page 17

2. Use the template (supplied with the boiler) to mark the required flue position and cut a 130 mm diameter hole for the flue
(use a 127 mm core drill). The size of the hole provides sufficient clearance for the clamps on the flue extension to pass
through the hole.
3. Determine the overall flue length as described in Section 4.6, paragraph 2 to determine the number of Alpha CD 750/1000 mm
flue extensions required.
4. Assemble the flue extensions together by locating the inner duct into the seal joint and secure each extension together
with the clamps supplied (three screws). Ensure that the clamps are positioned centrally over the joints.
Note: If it is required to cut an extension, DO NOT cut the end of the inner duct that incorporates the seal joint. Ensure the
inner duct end without the seal joint is cut so that it is 15 mm longer than the outer duct.
5. Adjust the telescopic section of the Easy-Flue to the required length and secure the Easy-Flue with the sealing tape
supplied. Fit the Easy-Flue to the extensions by locating the inner duct into the seal joint and secure with the clamp (three
screws), ensuring it is located centrally over the joint.
6. Mark the end of the flue assembly 'TOP' where it is connected to the boiler,so that the 'TOP' of the flue terminal is aligned
with the 'TOP' at the boiler end of the flue assembly.
7. Pass the complete flue assembly through the wall.
8. Position the seal and clamp (two screws) supplied, over the bend. Fit the bend to the boiler and rotate to the correct
position and secure in position using the seal and clamp, ensuring that the seal is positioned centrally over both the bend
and adaptor.
9. Slide the clamp (three screws) over the outer duct and pull the flue assembly towards the bend, locating the inner duct into
the seal joint on the bend.
10. Secure the flue assembly to the bend with the clamp (three screws) ensuring it is positioned centrally over the joint,
ensuring the 'TOP' marked on the outer duct is positioned at the top.
Note: Check the flue terminal protrudes 100 mm out of the wall and that the inner duct of the terminal is positioned
correctly, i.e. the inner duct within the terminal is at the top. See Fig. 19.
11. Make good the outside wall by fitting a flue sealing collar onto the location provided immediately behind the flue terminal
grille. Make good the inside wall as required.
Note: If flue sealing collars are being used to make good the inside wall, then they will need to be fitted before assembling
the flue.
Ensure the inner duct within
the terminal is at the top.
Note: The inner duct must
be positioned to slope towards
the boiler
90
Flue
terminal
Flue sealing
collar
CD Easy-Flue
Inner seal joint
Note: Ensure the flue extension slopes
downwards towards the boiler by a minimum
of 25 - 30 mm per metre
Flue length (L)
Fig. 19 - Side flue
Outer duct clamp
Inner seal joint
CD Flue extension
125
Alpha CD25C/28C/35C - Installation
90° bend
Clamp
and seal
Seal joint
25
Boiler front
220 220
17