General; Description Of The Appliance - A.O. Smith EQ 115 G Installation And User Instructions Manual

1.

GENERAL

1.1 Description of the
appliance
Construction of the water heater is in
accordance with the European
standard for gas heated water storage
heaters for sanitary application (EN 89).
The appliance thus meets the European
Directory for Gas Appliances and is
therefore entitled to carry the CE-
marking. It is an open flued appliance
without ventilator and with a flue gas
down draught safeguard (category
B11BS). The water heater is suitable
for a maximum working pressure of 8
bar. The water-heater tank is
manufactured from low carbon sheet
steel and is glass-lined on the inside. In
addition the tank is fitted with a
sacrificial anode as an extra protection
against corrosion.
A thick PU-insulation layer covered in a
steel jacket reduces unnecessary heat
loss. When the appliance is filled with
water it continuously is under water
pressure.
As hot water is drained from the tank,
cold water is added immediately. A flue
baffle has been placed in the flue tube
to improve heat transfer. The flue
gasses pass their heat on to the water
by means of radiation and convection.
The flue gasses are guided to the
chimney via the draught diverter. The
exhaust of the flue gasses is realized
by natural thermal draught (see Figure
1).
Dead legs on a hot water installation are
undesireable. Where possible they
should be avoided. Where the inclusion
on the system of a dead leg is
unavoidable the following restrictions
should be applied:
- for pipes not exceeding 19 mm.
inside diameter; maximum lengh of
dead leg permitted 12.0 metres;
- for pipes exceeding 19 mm. but not
4
exceeding 25 mm. inside diameter;
maximum length of dead leg 7.5
metres;
- for pipes with an inside diameter
exceeding 25 mm. maximum dead leg
3.0 metres.