Baxi System 100 HE Plus Installation & Servicing Instructions Manual page 17

Termination to an internal soil and vent
Boiler
450mm min
Boiler
Sink
Boiler
Termination to a purpose made soak-
Boiler
pipe
External termination via internal discharge
branch
e.g sink waste - downstream
Pipe must terminate
above water level but
below surrounding
surface
Termination to a drain or gully
Pipe must terminate above
water level but below
surrounding surface
away
500mm min
Holes in the soak-away must
face away from the building
7.0 Site Requirements
7.6 Condensate Drain
FAILURE TO INSTALL THE CONDENSATE
DISCHARGE PIPEWORK CORRECTLY WILL AFFECT
THE RELIABLE OPERATION OF THE BOILER
The condensate discharge pipe MUST NOT RISE at any
point along its length. There MUST be a fall of AT LEAST
2.5° (50mm per metre) along the entire run.
NOTE: It is unnecessary to fit an air break in the
discharge pipe.
1. The condensate outlet terminates in a 1" BSP nut and seal
3
for the connection of 21.5mm (
which should generally discharge internally into the household
drainage system. If this is not possible, discharge into an outside
drain is acceptable.
2. Ensure the discharge of condensate complies with any
national or local regulations in force.
BS 6798:2000 & Part H1 of the Building Regulations give
further guidance.
3. The discharge pipe should be run in a proprietary drain pipe
material e.g. PVC, PVC-U, ABS, PVC-C or PP.
4. Metal pipework is NOT suitable for use in condensate
discharge systems.
5. The pipe should be a minimum of 21.5mm diameter and
must be supported using suitably spaced clips to prevent
sagging.
6. Any pipe fitted externally must be kept as short as possible
to minimise the potential of freezing.
7. Any condensate discharge pipework external to the building
(or in an unheated part of it e.g. garage) must be insulated to
protect against frost. It is also recommended that the pipe
diameter is increased to 32mm.
8. If the boiler is fitted in an unheated location the entire
condensate discharge pipe should be treated as an external
run.
9. In all cases discharge pipe must be installed to aid disposal of
the condensate. To reduce the risk of condensate being
trapped, as few bends and fittings as possible should be used.
10. When discharging condensate into a soil stack or waste
pipe the effects of existing plumbing must be considered. If soil
pipes or waste pipes are subjected to internal pressure
fluctuations when WC's are flushed or sinks emptied then
back-pressure may force water out of the boiler trap and cause
appliance lockout.
Examples are shown of the following methods of termination:-
i) to an internal soil & vent pipe
ii) via an internal discharge branch (e.g. sink waste)
iii) to a drain or gully
iv) to a purpose made soakaway
/ in) plastic overflow pipe
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