Cutting The Flue Ducts To Length - Alpha CB Boiler Installation Instructions

2. CUTTING THE FLUE DUCTS TO LENGTH

Refer to the Installation and Servicing instructions supplied with the boiler.
The following procedure applies to both rear or side exit flue. The only difference being the lengths to which the ducts are cut.
Rear flue Outer air duct length = finished wall thickness + 135 mm
Inner flue duct length = finished wall thickness + 172 mm
Side flue Outer air duct length = finished wall thickness + the distance from the inside wall to the side of the
boiler + 145 mm
Inner flue duct length = finished wall thickness + the distance from the inside wall to the side of the
boiler + 182 mm
If the overall length of the inner duct is greater than 790 or 1040 mm, then another flue extension is required.
Note: When cutting the flue ducts ensure that all cuts are square and burr free.
Alpha Therm Limited.
Nepicar House, London Road, Wrotham Heath,
Sevenoaks, Kent TN15 7RS
Technical Helpline: 0870 3001 964
email: info@alphatherm.co.uk
website: www.alpha-innovation.co.uk
Compiled and designed by Publications 2000, Tel (01670) 356211
Fig. 2 - Rear flue
Fig. 3 - Side flue
These guidelines have been carefully prepared but we reserve the right to
alter the specification at any time in the interest of product improvement.
© Alpha Therm Limited 2004.
Note: If flue is more
than 1.5 m, the
restrictor must be
removed.
Part No. 6.9174342
04/04/D131