Potterton Performa 24i HE Installation And Service Instructions Manual page 22

Wall Thickness
(X)
(X)
Fig. 22
22
Fig. 20
Flue Elbow
Adaptor
Fig. 21
Wall Thickness
8.0 INSTALLATION
8.7 Fitting The Flue
HORIZONTAL FLUE
1. The standard flue is suitable for lengths between
100mm minimum and 685mm maximum, as
measured from the edge of the flue elbow outlet to
the joint between the terminal and air duct (Fig. 20).
2. Locate the flue elbow on the adaptor at the top of
the boiler. Set the elbow to the required orientation
(Fig. 21).
NOTE: The flue elbow is angled at 93 degrees to
ensure a fall back to the boiler.
3. Measure the distance from the outside wall face to
the elbow. This dimension will be known as 'X'
(Fig. 22).
4. To dimension 'X' add 50mm. This dimension to be
known as 'Y'.
IMPORTANT: Check all dimensions before
cutting.
Publication No. 5111813