Strebel S-FX 125, Installation Operating & Maintenance Manual

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8 FLUE GAS AND AIR SUPPLY SYSTEM
8.1 General
The S-FX boiler range is a B23 type with combustion air drawn from the place of installation, and exhaust fumes
discharged by means of a combustion fan (operation with flue pressurised) direct to outside air via a flue system.
Description
S-FX Boiler Range
70 125 220 320
Flue Pressure the Fan can Overcome 200 200 200 200 Pa
Notice:
•
Install all horizontal flue components with an angle of 3° downwards in the direction of the boiler (roughly
equal to five centimetres for every linear meter). When not installed accordingly, it may result in condensate
building-up in the flue gas tube, eventually causing component failure.
•
When using a wall terminal, there is the possible risk of ice building-up on surrounding parts/structures,
because the condensate will freeze. This risk should be taken into account during the design phase of the
heating installation.
•
In line flue condensate drains must be used with flue runs longer than 4 meters with the condense drainpipe
going to a sewage system.
•
Because the flue gases can have a low temperature, the boiler needs to have a high efficiency approved
stainless steel or plastic flue system. These materials, including the gaskets, should be usable for positive
pressure flue gas systems and have a temperature class of
T120. Meaning: the parts must be certified for
use at temperatures of minimal 120 °C ( See also warnings below).
Note:
In general, gas heaters are certified with their own flue gas material. The gas heater must be provided with high
efficiency SS or PP flue gas components available. The parts have to be qualified for an overpressure class P1 or
H1 and a temperature class of T120 minimum.
Never use aluminium flue with the S-FX boilers
B23 Type
•
S-FX appliances are equipped with an exhaust flue gas sensor,
which in the event of irregular temperatures will close down the
operation of the boiler.
•
The flue duct must be correctly sized. Inadequate or incorrectly
sized flues will cause problems with combustion parameters
and excessive noise.
•
For the flue duct, the use of stainless steel piping is
recommended, in compliance with standards
EN1856-1 and EN1856-2.
•
Ensure any horizontal flue runs have a 3 degree fall
back.
•
Inline flue condensate drainage points must be
installed connected directly traps with flue runs over
4 metres.
•
Common exhaust flues must be sized to a zero pressure
with all but one boiler firing in high fire.