Doc No. 700015 Page 6 of 36
to the heater not to apply excessive turning
force to the internal controls.
A flexible hose is installed to allow safe linear
expansion of the heater without creating undue
stress on the gas supply pipe work. It is
therefore important that a tested and certified
hose assembly made to ISO 10380, supplied
with ½” BSP female cone seat adapters, is
installed as per these instructions.
It is also important to ensure that expansion is
taken up in the body of the flexible hose, and
not on its attachment to the pipe work. The cone
seat adapter supplied on one end of the flexible
gas hose provides a `swivel` action, and must
be fitted on the burner using a ½” BSP barrel
nipple to provide ease of disconnection for
future servicing. This assumes that the heater
and fixed gas supply to the isolating valve have
been installed.
The installation layout described later is the
only method recommended by the
institute
of
gas
engineers,
the
hose
manufacturer, and Nortek Global HVAC (UK)
Ltd and must only be carried out by a qualified/
competent gas engineer.
fig.a
fig.c
Arrow denotes
direction of
expansion.
Depending on the specific installation, the
flexible gas hose may be routed to the gas
cock at any of the following angles in relation to
the burner:
Vertical (fig.a)
45° angle
(fig.b)
90° angle
(fig.c)
Any other position in between these angles is
acceptable.
A clearance distance ‘x’ of min 200mm
must be observed to allow side door
access .
Care must be taken to observe the minimum
pipe
bend
diameter
(minimum
250mm,
maximum 350mm) & pipe expansion distance
(minimum 30mm, maximum 70mm) as shown in
fig.e.
Maximum bend diameter for the 1000mm
hose is 450mm.
The correct installation as shown will allow
for approx 100mm of movement due to
expansion.
x
x
fig.b
fig.d
1.5 Gas Connection and Supply
Before installation, check that the local
distribution conditions, nature of gas
and pressure, and adjustment of the
appliance are compatible.
A competent or qualified engineer is required to
either install a new gas meter to the service
pipe or to check that the existing meter is
adequate to deal with the rate of gas supply
required. Installation pipes should be fitted in
accordance with BS 6896, so that the supply
pressure, as stated in Table 2 will be achieved.
It is the responsibility of the competent engineer
to ensure that other relevant Standards and
Codes of Practice are complied with in the
country of installation. Pipes of smaller size
than the heater inlet gas connection must not
be used. The complete installation must be
tested for soundness as described in the
country of installation.
The gas union service cock MUST be
fitted in the gas supply close to the
heater, but not onto the burner itself.
Take care when making a gas connection
fig.e
300 +/- 50mm
Burne
50 +/- 20mm
Figure 3. Correct Installation of Flexible Gas Connection
