Installation
1
Installation and maintenance instructions for wall-mounted condensing gas boiler 600 - 28C • 01/2004
13
Subject to modifications resulting from technical improvements!
Boulter Buderus Ltd. • http://www.boulter-boilers.com
Material for condensate
The condensate drainage pipe should be run in a standard
drain pipe material, e.g. PVC (polyvinyl chloride), PVC-U
(unplasticized polyvinyl chloride), BS (acrylonitrile-butadienes-
tyrene), PP (polypropylene polyprolene) or PVC-C (cross-
linked polyvinyl chloride).
Any internal pipework should be of a diameter to match the
requirements of the condensate exit pipe on the appliance.
A 32 mm (1¼") waste pipe solvent weld fitting can be used,
fitted externally over the condensate exit pipe on the appli-
ance.
All external pipework should be kept to a minimum to avoid
freezing and should have a diameter of not less than 22 mm.
Internal termination to internal stack
The condensate drainage pipe should have a minimum diam-
eter of 22 mm with no length restriction. It should incorporate a
trap with a 75 mm condensate seal and be connected to the
stack at a point at least 450 mm above the invert of the stack.
The trap built into the boiler will provide this 75 mm condensate
seal. For all internal and external stack connections a second
trap is required to prevent any odours emanating from the
condensate air break at the boiler (see fig. 10).
External termination via internal branch (e.g. sink waste)
The condensate drainage pipe should have a minimum diam-
eter of 22 mm with no length restriction and should incorporate
a trap with a 75 mm seal. The connection should preferably be
made downstream of the sink waste trap. If the connection is
only possible upstream, then the air break is needed between
the two traps. This is normally provided by the sink waste pipe
(see fig. 11 and fig. 12).
fig. 10 Internal termination of condensate drainage pipe to internal
stack
No length restriction
Ø22 mm min.
75 mm min. trap
internal soil
and vent stack
invert
Boiler
450 mm min.
fig. 11 External termination of condensate drainage pipe via internal
discharge branch (e.g. sink waste) and condensate siphon
75 mm min. trap
No length restriction
Ø22 mm min.
Open end of pipe
direct into gully,
below ground but
above water level
Boiler
Sink
fig. 12 External termination of condensate drainage pipe via internal
discharge branch (e.g. sink waste – proprietary fitting) and
condensate siphon
No length
restriction
Boiler
Open end of pipe
direct into gully,
below ground but
above water level
75 mm min. trap
Ø22 mm min.
Sink
