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IND GUIDE INST 10-11
HHIC REF T11/0027BRev8
Figure 4
–
Connection of condensate drainage pipe to external soil and vent stack
Key
1
Boiler
7
450 mm minimum up to three storeys
2
Visible air break
8
Minimum internal diameter 19 mm
3
75 mm trap
9
Pipe size transition point
4
Visible air break and trap not required if
there is a trap with a minimum condensate
seal of 75 mm incorporated into the boiler.
10
Minimum internal diameter 30 mm
11
Water/weather proof insulation
5
Soil and vent stack
6
Invert
