Bosch Worcester Greenstar CDi Classic System ErP Series Installation, Commissioning And Servicing Instructions page 13

▶ The pipe should be run internally as far as possible before going
externally and the pipe diameter should be increased to 32mm
before it passes through the wall to the exterior.
▶ The external pipe should take the shortest and least exposed route to
the discharge point, and should "fall" as steeply as possible away
from the appliance, with no horizontal runs in which condensate
might stand.
▶ The use of fittings, elbows etc. should be kept to a minimum and any
internal "burrs" on cut pipe work should be removed so that the
internal pipe section is as smooth as possible.
Fitting an external air break
• Refer to figure 10 when a rain water down pipe is used to dispose of
condensate.
• An air break must be installed in the 43mm pipe work, between the
appliance condensate outlet and the drainpipe, outside the property,
to avoid flooding during adverse weather conditions.
1
14
Fig. 10 Disposal into a rainwater down pipe
Where the pipe terminates over an open drain or gully, the pipe should
terminate below the grating level, but above water level, in order to
minimise "wind chill" at the open end.
The use of a drain cover (such as those used to prevent blockage by
leaves) may offer further protection from wind chill.
Pipe drainage will be improved if the end is cut at 45 ° as opposed to a
straight cut.
1
14
Fig. 11 External disposal
6 720 815 724 (2015/11)
17
13
15
16
18 8
13
25mm min.
14
1
7
Fig. 12 Condensate pump to external disposal
Condensate soak away
• The condensate drainage pipe may be run above or below the ground
to the soak away. The examples shown on this page run above
ground.
• The soak away must use a 100mm Ø plastic tube with two rows of
three 12mm holes on 25mm centres and 50mm from the bottom of
the tube. The holes must face away from the house.
• The tube must be filled with and surrounded by at least 100mm of
limestone chippings to a depth of 400mm.
Minimum hole size for the condensate soak away must be
400mm deep by 300mmØ .
1
500mm min.
13
14
9
11
12
Fig. 13 Soak away
PRE-INSTALLATION
13
25mm min.
6720644744-12.3Wo
9
10
25mm min.
400mm
min.
10
13