Halstead Eden CBX, Installation And Servicing Instructions

Page: 35 / 47

INCLUDING AIR INLET COWL
9.3 GAS CONTROL VALVE
Refer to Figures 33, 34 & 35
a)
Ensure supply voltage is isolated, and that the gas supply is isolated.
b) Remove the gas control valve, fan & burner assembly; refer to
section 6.2.
c) Unscrew four screws holding the gas feed pipe, and remove gas
feed pipe, refer to Figure 33.
Note: Newer versions may have a single flange nut
securing the gas feed pipe.
d)
Unscrew three tork screws (T-20), and remove gas control valve,
refer to Figure 34
e) Unclip the top section of the black plastic air inlet cowl from the fan
assembly, and remove white plastic insert, clean or replace as
necessary, refer to Figure 35.
f) Refit or replace the top section of the black plastic air inlet cowl,
ensuring that it is clipped into place and that the holes in the white
plastic insert are aligned with the fixing holes.
g) Attach and secure the gas feed pipe to the replacement gas valve,
using a new gasket.
h) Attach and secure the replacement gas control valve to the fan
assembly.
i) Re-assemble in reverse order; ensure that all joints and seals are
correctly re-fitted.
Note: The gas control valve is factory set and sealed and is not
adjustable. If the gas control valve is changed, then when the appliance
is running, the flue gas CO
2
should be measured, refer to section 6.1,
and compared to the values stated in Performance Data, section 2.2. If
the measured value does not correspond to the Performance Data, then
contact: Halstead Boilers Ltd. Service Help line: 08450 710780.
33
GAS FEED PIPE CONNECTION TO GAS
CONTROL VALVE
34
GAS CONTROL VALVE
35
AIR INLET COWL
33
If a new gas valve is fitted it must be adjusted as per the
instructions that are supplied with the new gas valve.
A suitable, calibrated flue gas analyser is required to measure the
CO
2
.
9.3.2 COMBUSTION CHECK SET-UP
When installing, commissioning or servicing
a gas appliance that incorporates a pre-mix
burner and zero-set governor, because it is
not possible to measure an operating
pressure the engineer should first check that the gas
supply is metered and ascertain whether it is possible
to measure the gas rate. If the gas input rate can be
measured then the requirements of GSIUR 26(9) can be
met, including any specific requirements in
manufacturers’ instructions.
If gas input rate cannot be measured then, to satisfy
the intent of GSIUR 26(9), the engineer shall measure
the combustion quality of the appliance in accordance
with BS 7967 or the manufacturers’ instructions.
If the engineer does not have the required equipment
and no alternative test is specified by the manufacturer
then the appliance shall be turned off and disconnected
as an un-commissioned appliance until such time that
equipment is available to undertake such tests.
!