UK Manufactured Unvented Hot Water Cylinder Installation Guide
49
The discharge will consist of scalding water and steam. Asphalt, roofing felt
and non-metallic rainwater goods may be damaged by such discharges.
It is not acceptable to discharge straight into a soil pipe.
Safety Device
(temperature relief valve)
Metal discharge pipe (D2) from
temperature relief valve to tundish
Minimum 300mm
Maximum 600mm
Tundish
Discharge below fixed grating
(Building Regulation G3 section 3.61 gives
alternative points to of discharge)
Trapped Gulley
Fixed Grating
Metal discharge pipe (D2) from
tundish, with continuous fall.
(See Building Regulation G3
section 3.56, Table 1 and worked
example)
