26
Grant Vortex Oil Boilers
Fig. 17 - Condensate trap
General - Grant boilers are compatible with both
copper and plastic pipe. Where plastic pipe is used it
must be of the oxygen barrier type and be of the
correct class (to BS 7291:Part 1:1990) for the
application concerned.
IMPORTANT: The first metre of pipework
connected to both the heating flow and return
connections of the boiler must be made in copper on
all types of system - sealed or open-vented..
Sealed systems - If plastic pipe is to be used, the
installer must check with the plastic pipe manufacturer
that the pipe to be used is suitable for the temperature
and pressures concerned. Pipe must be Class S to BS
7291: Part 1:1990.
The system should incorporate a low-pressure switch
to shut off power to the boiler if the system pressure
drops below 0.2 bar. A suitable low pressure switch kit
is available to purchase from Grant Engineering (UK)
Limited, Part No. MPCBS 62.
Underfloor systems - Plastic pipe may be used on
Underfloor systems where the plastic pipe is fitted
after the thermostatic mixing valve. Copper tube must
be used for at least the first metre of flow and return
primary pipework between the boiler and the
underfloor mixing/blending valves.
When in condensing mode the Grant Vortex 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 20 mm - e.g. 22 mm plastic
plumbing pipe or 19 mm (¾") plastic overflow pipe.
Condensate disposal pipes must be fitted with a fall of
2.5° (1:20).
4 - GENERAL BOILER INFORMATION
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 32 mm 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 trap
Condensate disposal pipes MUST be fitted with a trap
- whether they are connected internally or externally.
All Grant Vortex boilers are supplied with a
condensate trap to provide the required 75 mm 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. 17.
Pipework materials
4.16
Condensate disposal
4.17
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.
