Soil & vent stack
22mmØ
minimum
450mm
and up to
3 storeys
Condensing
Boiler
Invert
Condensate drainage pipe can be
run above or below ground
25mm
Bottom of
tube sealed
Limestone
chippings
Hole depth
400mm min.
by 300 Ø
Drainage holes
22mmØ condensate
drainage pipe, max external
length 3 metres
Diameter 100mm
min. plastic tube
500mm min.
75 mm
min.
Condensing
Boiler
22mmØ
plastic pipe
75mm sink
waste trap
Open end of
condensate drainage
pipe directly into gully
below grating but
above water level
Visible air break
at plug hole
22 mm Ø plastic condensate
drainage pipe running
through the external wall
External
air break
Air gap
External rain water
pipe into foul water
68 mm Ø PVC-u
strap on fitting
43 mm 90°
M & F bend
100mm
Sink with
integral
overflow
Condensing
Boiler
Insulation or
increase pipe size
Insulation or
increase pipe size
Insulation or
increase pipe size
CONDENSATE PIPEWORK
Fitting an external air break
Use the situation opposite when a rain water
down pipe is used to dispose of condensate
and the down pipe goes directly into an existing
sewer that carries both rainwater and foul
water.
An air break must be installed in the 32/43 mm
pipework, between the boiler condensate outlet
and the drainpipe, outside the property, to avoid
flooding during adverse weather conditions.
CONDENSATE PIPEWORK:
The condensate pipe must be a minimum of
22 mm Ø plastic pipe.
The condensate pipework must fall at
least 50 mm per metre towards the outlet
and should take the shortest practicable
route.
The pipework must follow one of the options
shown opposite.
Wherever possible the condensate
discharge pipe work should be routed and
terminated internally. Should this not be
possible, and the only available route is
external, the following conditions should be
observed:
External pipe work
Pipe work length should be kept to a
minimum and the route as vertical as
possible.
Where pipe work is subjected to extreme
cold or wind chill, a weather proof insulation
should be used.
Alternatively the condensate pipework
could be increased to a minimum
diameter of 32 mm without the
requirement to insulate.
h
IMPORTANT:
•
Ensure there are no
blockages in the pipe run
•
Care should be taken when
siting a soak-away to avoid
obstructing existing services
•
Condensate waste must not
be terminated into a septic
tank or cesspit
Condensate soakaway
The condensate drainage pipe may be run
above or below the ground to the soakaway.
The example shown opposite runs above
ground level.
The soakaway must use a 100mm diameter
plastic tube with two rows of three 12 mm
holes on 25 mm centres and 50 mm from the
bottom of the tube. The holes must face away
from the house.
The tube must be surrounded by at least 100
mm of limestone chippings to a depth of
400mm.
CONDENSATE PIPEWORK
INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER GREENSTAR Ri
8 716 115 168a (06/2008)
9
P
R
E -
IN
ST
AL
LA
TI
O
N
