Supplied By www.heating spares.co Tel. 0161 620 6677
6
2.4
VENTILATION REQUIREMENTS
Detailled recommendations for air supply are given in
BS5440:2. The following notes are for general guidance:
– It is not necessary to have a purpose provided air vent in the
room or compartment in which the appliance is installed.
2.5
GAS SUPPLY
– The gas ins t allation should be in accor dance wit h
BS6891. The gas required for the boiler is specified in
Table 4.
– Ensure that the pipework from the meter to the appliance
is of adequate size.
– The governor at the meter must give a constant outlet
pressure of 20 mbar (8 inwg) for natural gas and 30 - 37
mbar (12 - 15 inwg) for LPG, when the appliance is running.
– The gas supply line should be purged.
NOTE: Before purging open all doors and windows, also
extinguish any cigarettes, pipes, and any other naked
flames.
– The complete installation must be tested for gas soundness.
2.6
ELECTRICITY SUPPLY
The appliance MUST be earthed. A mains supply of 230 V -
50 Hz single phase is required. All external controls and
wiring MUST be suitable for mains voltage.
Wiring should be in 3 core PVC insulated cable NOT LESS
than 0.75 mm
2
(24 x 0.2 mm) to BS6500, Table 16. Wiring
external to the boiler MUST be in accordance with current
l.E.E. Wiring Regulations (BS 7671) and local regulations. The
supply connection to the flying lead provided MUST be made
to a fused double pole switch, having a 3 mm (1/8 in) contact
separation in both poles, serving only the boiler and system
controls; the fuse rating should be 3 amp. This connection
should be readily accessible and be made adjacent to the boil-
er (except in the case of bathroom installations for domestic
boilers where the point of connection to the mains MUST be
outside of the bathroom).
2.7
EXTERNAL CONTROLS (Refer to section 3.9)
The boiler is intended for use with a 24 V room thermostat.
The connection is made inside the control box as described in
section 3.9.
2.8
WATER SYSTEMS - GENERAL
– This appliance is designed for connection to sealed cen-
tral heating water systems.
– Check that the mains water pressure is sufficient to pro-
duce the required D.H.W. flow rate, but does not exceed
the maximum D.H.W. pressure (
Table 4).
Where mains
pressure exceed 6 bar a pressure reducing valve must
be fitted in the D.H.W. inlet.
2.8.1 Treatment of Water Circulating Systems
– All recirculatory systems will be subject to corrosion
unless an appropriate water treatment is applied. This
means that the efficiency of the system will deteriorate as
corrosion sludge accumulates within the system, risking
damage to pump and valves, boiler noise and circulation
problems.
– For optimum performance after installation this boiler
and its associated central heating system must be
flushed in accordance with the guidelines given in BS
7593 “Treatment of water in domestic hot water central
heating systems”.
– This must involve the use of a proprietary cleanser, such
as BetzDearborn Sentinel X300 or X400, or Fernox
Superfloc. Full instructions are supplied with the products,
but for immediate information please contact BetzDear-
born (0151 420 9563) or Fernox (01799 550 811)
directly.
– For long term protection against corrosion and scale,
after flushing it is recommended that an inhibitor such as
BetzDearborn Sentinel X100, or Fernox MB-1 or Copal is
dosed in accordance with the guidelines given in BS
7593.
Failure to flush and add inhibitor to the system may
invalidate the appliance warranty.
– It is important to check the inhibitor concentration after
installation, system modification and at every service in
accordance with the manufacturer’s instructions. (Test
kits are available from inhibitor stockists).
2.9
REQUIREMENTS FOR SEALED WATER SYSTEMS
The heating system design should be based on the following
information:
a) The available pump head is given in fig. 5.
b) The burner starts when the C.H. flow reaches 400÷450
l/h. This safety condition is ensured by the flow switch.
c) The appliance is equipped with an internal by-pass that
operates with system heads (H) greater than 3 m. The
maximum flow through the by-pass is about 300 l/h. If
thermostatic radiator valves are to be installed, at least
one radiator should be without a thermostatic valve (usu-
ally the bathroom radiator).
d) A sealed system must only be filled by a competent per-
son using one of the approved methods shown in fig. 7.
0
200
1600
1400
1200
1000
800
600
400
PORTATA (l/h)
PREV
ALENZA RESIDU
A (mbar)
500
400
100
200
300
30 - 35
25
For
mat.zip
KEY
1
Available Head for
“80 C - 100 C”
models
2
Available Head for
“110 C”
model
Flow rate (l/sec)
A
vailable
head
(mbar)
Fig. 5
1
2
