ULTRAMAX PB 65 - 120
17 L290 ©MHS Boilers 13/12/2010
4.0 Installation instructions cont.
4.5 Connection to air/exhaust system through an existing chimney.
For the concentric air/exhaust system, use original accessory parts only, including the PPS exhaust system
lubricant available. Gas condensing boilers with an air/exhaust system via an existing chimney to the roof
must be installed in the attic or in rooms in which the ceiling is also the roof, or where the only thing above the
ceiling is the roof construction. Unless using a flexible liner to the relevant standards.
The air/exhaust system must not be routed through any other storage rooms. Unless using a flexible liner to
the relevant standards.
If the ceiling requires certain fire resistance duration, all conduits for the combustion air supply and the
exhaust ventilation must have a similar fire shielding of non-flammable materials between the top of the
ceiling and the roof skin.
If no such fire resistance duration is required for the ceiling, all conduits for the combustion air supply and the
exhaust ventilation must be routed inside a shaft of non-flammable and shape-resistant materials or inside a
metal protective pipe between the top of the ceiling and the roof skin (mechanical protection). Exhaust
conduits must be able to be checked for free passage. The installation must be equipped with at least one
inspection opening for maintenance purposes.
Sleeve and seal shall make exhaust-side connections. All sleeves must be placed counter to the flow
direction of the condensate. The air/exhaust system must have a 3° slope towards the condensing boiler.
The overall length to be calculated for the air/exhaust system shall not exceed 15m for an installation against
the exterior wall or for an air/exhaust system through the roof. The calculated length of the air/exhaust
system consists of the length of straight pipes plus the length of pipe bends. A 90° bend is calculated at 1 m,
a 45° bend as 0.8m in length.
We recommend a minimum distance of 2.5m between the combustion air supply and exhaust routing through
the roof in order to avoid effects upon each other.
4.6 Connection to moisture-resistant air/exhaust chimney, exhaust chimney, or exhaust system.
Chimneys as exhaust systems may be permitted for gas condensing boilers by the building and local
authorities. Using the calculation tables pursuant to the respective exhaust values category specifies the
dimensions. A maximum number of three 90° angles are permitted for the installation. For chimneys a
conveyance pressure of 0 Pa is applied for calculation purposes.
4.7 Connection to moisture-resistant air/exhaust chimney C43x
The straight air/exhaust system for installation in an air/exhaust chimney must not be longer than 1.4m. A
maximum number of three 90° angles are permitted for the installation.
4.8 Connection to moisture-resistant exhaust chimney or exhaust system B23 for room air
independent operation
The straight air/exhaust system for installation in an exhaust chimney must not be longer than 2m. A
maximum number of three 90° angles are permitted for the installation.
