FLUE SYSTEMS
Andrews Water Heaters’ ECOflo is a Balanced Flue, Gas
Water Heater where all air for combustion is obtained
from the outside atmosphere and all flue gases are
discharged to the outside atmosphere. The flue system is
a single concentric (pipe within pipe) design where the
flue products are discharged through the inside flue tube
and the combustion air supply surrounds the flue
surrounded by the outside pipe. The flue system
incorporates both combustion air supply and the flue
exhaust. The flue system component which is outside the
building, takes in the combustion air supply and
discharges the flue products (whilst keeping them
separate) is referred to as the ‘direct flue terminal’.
WARNING!
The direct flue systems MUST be properly installed.
Failure to do so could results in property damage or
personal injury. DO NOT install any damaged
components. Contact Andrews Water Heaters for
replacement parts. The flow of combustion air must not
be restricted. Keep direct flue terminal openings clear of
any objects likely to cause flow restriction.
Direct Flue Terminal
Shall terminate at least 1.5m (5ft) above any forced air
inlet located on the same wall. This provision does not
apply to the combustion air intake of a direct flue
appliance or the circulating air inlet and flue gas discharge
of listed outdoor appliances.
Shall be installed with at least a 300mm (12in) flue
termination clearance from any air opening into a building.
The bottom of the direct flue terminal shall be located at
least 300mm (12in) above ground.
Consideration should be given to the location of the flue
terminal. The flue terminal should be located where the
discharge of flue products does not cause a nuisance.
Consideration should also be given with regard to noise
that may be emitted by this flue system. In all cases the
flue termination must meet the requirements of BS6644.
A suitable terminal guard must be fitted if less than 2
metres above ground level.
OPTIONAL CONVENTIONAL FLUE
(OPEN FLUE)
This is an open flued arrangement where the air is drawn
into the appliance from within the plant room (boiler
house). Permanent ventilation is required to allow correct
operation of the appliance (refer to BS 6644).
Alternatively, the ventilation can be supplied by running
fresh air ducting
(150mm) direct
from outside,
terminating with
a suitable
terminal.
The maximum
‘combined’ flue
run is 32 metres.
The use of 90°
and 45° bends
will reduce the allowed overall length by 1.2m per 90°
and 0.7m per 45° bend used along the flue run.
NOTE:
The overall length does not include the 1m
terminal. The 1m terminal is not to be included in
determining the overall length of the flue.
Maximum Flue Distances (Horizontal or Vertical)
Number of 90° Elbows
Maximum length of straight
pipe (excluding flue terminal)
to exterior wall
0
16m (52ft 6in)
1
14.8m (48ft 6in)
2
13.6m (44ft 7in)
3
12.4m (40ft 7in)
NOTE:
Each 45° elbow reduces the maximum flue
distance by 700mm (2ft 3in).
IMPORTANT: Do not exceed the flue distances or
the number of elbows listed above. This may cause
heater malfunction or unsafe conditions.
SECTION 3 •
INSTALLATION
18
Conventional Flue Option
Combustion
via “T” piece
Exhaust
100mm
NB: 100 mm flue section
NOT available from
BAXI Commercial.
Vertical option, maximum
overall run is 32 meters
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