Bosch 12/18 User Manual

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K
J
b
E
C
Invert
450 min
.
A
c
D
A
C
75mm
min.
a
A
B
C
D
400mm
min.
500mm min.
d
F
I
H
G
A
C
25mm
min.
200mm min.
(Unsuitable for clay soil types) 
CONDENSATE &
PRESSURE RELIEF PIPEWORK
INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER GREENSTAR HEATSLAVE EXTERNAL 12/18-18/25-25/32
8 716 113 389b (09/07) 
12
P
R
E -
IN
ST
AL
LA
TI
O
N
CONDENSATE &
PRESSURE RELIEF PIPEWORK
CONDENSATE PIPEWORK:
• All national and, where appropriate, local 
regulations for the discharge and 
neutralisation of condensate should be 
followed.
• The condensate pipe must be a minimum of 
21.5mmØ polypropylene pipe.
• The condensate pipework must fall at least 
50mm per metre towards the outlet and 
should take the shortest practicable route 
and not exceed 3 metres outside the building.
If a run greater than 3m is required, 32mmØ 
polypropylene pipe must be used. 
• The pipework must follow one of the options 
shown opposite: 
a - Internal waste drainage system
b - Soil/vent stack
c - External drainage system
d - External condensate absorption point
• Condensate pipework must not be connected
to rainwater downpipes.
• Use waterproof pipe insulation in exposed 
positions and for external pipework
IMPORTANT: Condensate pipework must not
leak and the condensate trap must be filled
with water before the boiler is started to
prevent the possibility of potentially harmful flue
products escaping via the condensate route.
A - Condensate from the boiler condensate 
trap (supplied) which has a 75mm 
minimum water seal.
B - Sink.
C - 21.5mm Ø polypropylene condensate pipe.
D - Gully.
E -
Internal soil and vent stack.
F -
300mm x 100mm Ø sealed plastic tube.
G - Ground level.
H - Drainage holes 50mm from base of tube
(12mm Ø at 25mm centres) facing away 
from building.
I -
Limestone chippings.
PRESSURE RELIEF PIPEWORK:
IMPORTANT: The pressure relief valve is a
safety device for the boiler and if activated may
discharge boiling water or steam through the
relief valve drain pipe.
Care should be taken when siting the outlet
pipe so that it does not cause an obstruction or
discharge above a window, entrance or other
public access where it could cause a hazard.
• The pressure relief drain pipe (K) should be 
at least 15mm diameter copper pipe and run 
downwards away from the boiler and  discharge
away from any electrics or other hazard,      
preferably to an external drain or soakaway.
• Pipe (K) should be finished with a partial 
bend, near the outlet to face the external    
boiler casing (as shown) to help prevent 
freezing.
J -
External boiler casing.
K -
Pressure relief pipe.