ecoTEC plus 937 installation and maintenance manual
26
• Connect the condensate drain (
1
) of the boiler to a
condensate drain pipe (
2
) which has a minimum
internal diameter of 19 mm (22 mm outside diameter
for all external pipes) and which is made from an acid-
resistant material (e.g. plastic overflow pipe).
h
Note!
The accessories for the storage tank include a
corrugated hose for draining the condensate.
Note!
The drain pipe connected to the condensate
drain of the combi boiler must have a constant
gradient (45 mm per metre) and should be
installed and terminate within the building to
prevent the possibility of freezing up.
The condensate drain pipe must terminate in a suitable
location, e.g.:
a)
preferably the discharge pipe should run and
terminate internally to the house soil and vent stack
(at least 450 mm above the invert of the stack). A
trap giving a water seal of at least 75 mm (
3
) (built
into the boiler) should be incorporated into the pipe
run, and there must be an air break (
4
) in the
discharge pipe upstream of the trap. The connection
to the stack should not be made in a way that could
cause cross flow into any other branch pipe, or from
that branch pipe into the condensate drainpipe. This
can be achieved by maintaining an offset between
branch pipes of at least 110 mm on a 100 mm diameter
stack and 250 mm on a 150 mm diameter stack.
b)
connecting into the internal discharge branch (e.g.
sink waste or washing machine) with an external
termination, the condensate discharge pipe should
have a minimum diameter of 22 mm with no length
restriction and should incorporate a trap with a
75 mm (
3
) (built into the boiler) seal. The connection
should preferably be made down stream of the sink
waste trap. If the connection is only possible
upstream, then an air break is needed between the
two traps. This is normally provided by the sink waste.
c)
terminating in a gully (
5
) below grid level (
6
) and
above the water level. The external pipe length should
be kept as short as possible to minimise the risk of
freezing and should not be more than 3 m.
d)
at a condensate absorption point (soakaway) (
7
). The
external pipe length should not be more than 3 m.
Further information can be obtained from "BS 6798
Specification for installation of gas–fired boilers of rated
input not exceeding 70 kW net“. The condensate siphon
must be filled with water as described in Section 5.6
before the combi boiler is commissioned.
min.
180
Fig. 4.12 Installation space condensate siphon
d
Danger!
Danger of poisoning!
In order to prevent exhaust gases from
escaping from the combi boiler via the siphon,
the siphon must be filled with water before the
unit is switched on.
The discharge pipes must therefore be installed
in such a way that they do not cause an
obstruction and sufficient clearance exists to
allow access to the condensate siphon.
There must be a minimum clearance of 180mm below
the siphon for access.
4 Sequence of operations during installation
