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When in condensing mode the Rayburn boiler produces
condensate from the water vapour in the flue gases.
Provision must be made for the safe and effective
removal of the condensate.
Condensate can be disposed either internally - into an
internal domestic waste system or directly into the soil
stack, or externally - to an external soil stack, gully,
hopper or soakaway.
It should be noted that connection of a condensate pipe to
the drain may be subject to local Building Control
requirements.
Pipework
Condensate disposal pipework must be plastic
(plastic waste pipe is suitable). Copper or steel pipe is
NOT suitable and should NOT be used.
The internal diameter of condensate disposal pipes
should not be less than 19mm - e.g. 22mm plastic
plumbing pipe or 19mm 3/4” plastic overflow pipe.
Condensate disposal pipes must be fitted with a fall
of 2.5° (1:20).
For boilers installed 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. in a
basement, it will be necessary to use a condensate pump.
Condensate disposal pipes should be kept as short as
possible and the number of bends kept to a minimum.
Pipes should be adequately fixed to prevent sagging, i.e.
at no more than 0.5 metre intervals.
Ideally, external pipework, or pipework in unheated areas
such as garages, should be avoided. If unavoidable,
external pipework should be kept as short as possible
(less than 3 metres) and 32mm waste pipe used to
minimise the risk of freezing.
The number of bends, fittings and joints on external pipes
should be kept to a minimum to reduce the risk of trapping
condensate.
Condensate disposal pipes MUST be fitted with a trap
- whether they are connected internally or externally.
Rayburn boilers are supplied with a condensate trap to
provide the required 75mm water seal in the condensate
discharge pipe from the boiler. This trap incorporates a
float (which will create a seal when the trap is empty) and
an overflow warning outlet (fitted with a rubber bung), See
Fig. 26.
The trap must be located internally in an accessible
position to allow for routine maintenance. The mounting
bracket supplied with the trap
MUST
be used - the trap
should
NOT
be supported by the condensate pipework
only.
A 22mm push-fit plastic plumbing connector is supplied
with the boiler to connect the plastic pipe to the stainless
steel condensate outlet pipe - on the left hand side of the
boiler,
Use 22mm plastic plumbing pipe between the boiler and
the inlet of the trap. Either 22mm plastic plumbing pipe or
19mm (3/4”) overflow pipe can be used from the outlet of
the trap.
NOTE:
Due to the wall thickness of plastic plumbing pipe,
it may be necessary to chamfer the internal edge of the
pipe before fitting it onto the spigot in the outlet of the trap.
If connecting the condensate discharge internally - into a
waste system or soil stack - the bung must be fitted in the
overflow outlet of the trap.
On external discharge systems to a gully or a soakaway,
the bung should be removed from the overflow outlet. If
connected to an external soil stack, the bung must be
fitted on the trap.
If there is any discharge of condensate from the overflow,
this could indicate a blockage (possibly due to freezing).
Turn off the boiler and contact your service engineer.
Installation Instructions
CONDENSATE DISPOSAL
CONDENSATE TRAP
Fig. 26
DESN 515916 A
