Baxi LUNA HT 1.450 Installation And Servicing Instructions page 23

Two Pipe Vent Support
All venting must be fixed every 3.28 ft (1.0 m) using steel strapping or equivalent.
Fig. 15
A: Steel strapping or equivalent
Note:
Ensure that the vent is sloped towards the boiler of approximately 0.39 in for every 3.28 ft (1.0 cm) for every 1.0 m
For horizontal flues a minor deviation from the horizontal is allowable, provided it results in a downward slope towards
the boiler.
Additional flue components are available as follows:
3.28 ft / 1.0 m flue
90° bend
45° bend
Vertical flue terminal assembly. Refer to the separate installation instructions supplied with the assembly.
WARNING
If an extra 90° bend is used, this reduces the maximum flue length by 3.28 ft / 1.0 m.
Each 45° bend used reduces the maximum flue length by 1.64 ft / 0.5 m.
4.1.3 approved venting materials
We recommend that the Condensing HT boiler be vented with the manufacturer's venting material. This can be with either
coaxial venting or with the two pipe rigid vent system.
To vent the Condensing HT boiler with ABS/PVC vent pipe there are a few things that have to be taken into consideration.
Use only materials listed below for vent pipe, intake air pipe and fittings. Failure to comply could result in personal injury,
death or property damage and could void the boiler warranty. Installations must comply with local code requirements and
with U.S.ANSI Z223.1
WARNING
All venting must be properly supported. The boilers are not intended to support any type of vent system
whatsoever. All piping, flue, solvents, cleaners, fittings and components must conform to ASTM and ANSI
standards.
Do not use any DWV plumbing pipes to vent this boiler.
Use of cellular core PVC (ASTM F891), cellular core CPVC, or Radel® (polyphenolsulfone) in venting systems
shall be prohibited.
Covering non-metallic vent pipe and fittings with thermal insulation shall be prohibited.
INSTALLATION AND SERVICING INSTRUCTIONS
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7110242.02 - en