Condensate Disposal
Page 19
6.1 GENERAL
REQUIREMENTS
When in condensing mode the Grant Vortex boilers produce
condensate from the water vapour in the fl ue gases.
This condensate is moderately acidic with a pH value of around
3.27.
Provision must be made for the safe and effective disposal of this
condensate.
Condensate can be disposed of using one of the following methods
of connection:
Internal connection (preferred option)
• into an internal domestic waste system (from kitchen sink,
washing machine, etc.)
• directly into the soil stack
External connection
• into an external soil stack
• into an external drain or gulley
• into a rainwater hopper (that is part of a combined system
where sewer carries both rainwater and foul water)
• purpose made soakaway
6.2
CONNECTIONS
Connections into a rainwater hopper, external drain or gulley
should be terminated inside the hopper/drain/gulley below the
grid level but above the water level.
Condensate should not be discharged into ‘grey water’ systems that
re-use water used in the home (not including water from toilets).
It should be noted that connection of a condensate pipe to the drain
may be subject to local Building Control requirements.
6.3
PIPEWORK
Condensate disposal pipework must be plastic (plastic waste or
overfl ow pipe is suitable).
Condensate disposal pipes should have a minimum ‘nominal’
diameter of 22 mm (¾ ) - e.g. use 21.5 mm OD polypropylene
overfl ow pipe.
Condensate disposal pipes must be fi tted with a fall (away from the
boiler) of at least 2.5° (~45 mm fall per metre run).
Condensate disposal pipes should be kept as short as possible and
the number of bends kept to a minimum.
Pipes should be adequately fi xed to prevent sagging, i.e. at no more
than 0.5 metre intervals.
6.4
EXTERNAL PIPEWORK
Ideally, external pipework, or pipework in unheated areas, should
be avoided. If unavoidable, external pipework should be kept as
short as possible (less than 3 metres) and 32 mm waste pipe used to
minimise the risk of ice blocking the pipe in freezing conditions.
The number of bends, fi ttings and joints on external pipes should be
kept to a minimum to reduce the risk of trapping condensate.
Ground level
32 mm waste pipe external to the building
Minimum 2.5 fall
O
25 mm
300 mm
400 mm
min.
Two rows of 3 x 12 mm
holes at 25 mm centres
and 50 mm from the bottom
of the tube. Holes facing
away from the property.
Cement seal
100 mm plastic tube
Sealed end
Backfill with 10 mm
limestone chippings
Figure 6-1:
Purpose made condensate soakaway
CONDENSATE DISPOSAL SYSTEM
6
WARNING
All condensate disposal pipes
must
be fi tted with a trap
- whether they are connected internally or externally to
a domestic waste system/soil stack or run externally to a
gulley, hopper or soakaway.
Condensate disposal pipes must not be
connected directly into rainwater downpipes
or to waste/soil systems connected to septic
tanks.
CAUTION
Copper or steel pipe is NOT suitable and MUST
NOT be used.
NOTE
Where it is not possible for the pipe to fall
towards the point of discharge - either
internally into a waste system or externally
to a gulley (e.g. for boilers installed in a
basement), it will be necessary to use a
condensate pump(CONPUMP).
NOTE
For boilers installed in an unheated area such
as a loft, basement, outhouse or garage, all
condensate pipework should be as ‘external’.
The pipework should be insulated using
suitable waterproof and weather resistant
insulation.
NOTE
