Section 5: Condensate Disposal
Page 16
5.1 General Requirements
When in condensing mode the Grant Vecta condensing wood
pellet boilers produce condensate from the water vapour in the flue
gases. This condensate is slightly acidic with a pH value of around
6. Provision must be made for the safe and effective disposal of this
condensate.
Condensate can be disposed using one of the following methods:
•
into a soil stack – either directly or via an existing waste system
•
into an gulley
all condensate disposal pipes must be fitted with a trap
whether
they are connected internally or externally to a domestic waste
system/soil stack or run externally to a gully or hopper.
Every Grant Vecta boiler is supplied with a trap and this MUSt
be used. Refer to Section 5.5 for trap details.
MCS Product Certification Scheme Requirements for Biomass (MCS
008) state that:
“Because of the volume of wash-down/condensate discharge, it is
NOT recommended to discharge into a purpose-made soakaway.”
5.2 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 disposal pipes can be connected directly into waste/soil
systems connected to septic tanks, providing a neutraliser has been
installed.
Condensate
must 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.
5.3 Pipework
Condensate disposal pipework must be plastic.
Copper or steel
pipe is not suitable and must nOt be used.
All condensate disposal pipes connected to a Grant Vecta boiler must
have a minimum ‘nominal’ diameter of 32mm (1 ¼”) plastic pipe.
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.
Condensate disposal pipes must be fitted with a fall (away from the
boiler) of at least 2.5° (
≈
45mm fall per metre run).
Where it is not possible for the pipe to fall towards the point of
discharge – either into a waste system or to a gulley, it will be
necessary to use a condensate pump.
When using a condensate pump with a Grant Vecta boiler, a
condensate holding tank of at least 40 litres is required. this is
to ensure that when the boiler cleaning cycle has operated the
holding tank can collect the total volume of the water used in the
wash system and the condensate pump can then discharge the
waste water effectively.
a boiler interlock should be fitted to shut off the boiler in the
event of a malfunction of the condensate pump. this must be
located indoors.
nOtE
!
5 Condensate Disposal
When using a condensate pump and holding tank, the Boiler
control setting for ‘Clean Boiler’ (time between boiler cleaning
operations) must not be set less than 480 minutes. Changing
this setting could result in a more frequent wash down of the
boiler which could exceed the capabilities of the tank and
condensate pump.
the ‘Max Cleaning time’’ (maximum time boiler cleaning is in
operation) is factory set at 60 seconds.
Refer to Section 9 for further details on boiler control settings.
!
WaRninG
5.4 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 38mm (1½”) waste pipe used to
minimise the risk of ice blocking the pipe in freezing conditions.
The number of bends, fitting and joints on external pipes should be
kept to a minimum to reduce the risk of trapping condensate.