8
4
2.9
APPLIANCE HYDRAULIC CIRCUITS
INCLUDING AIR INLET COWL
9.3
GAS CONTROL VALVE
Refer to Figures 35, 36 & 37
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 35.
d)
Unscrew three tork screws (T-20), and remove gas control
valve, refer to Figure 36.
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 37.
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: 01926 834834
37
AIR INLET COWL
35
GAS FEED PIPE
36
GAS CONTROL VALVE
Refer to Figures 37, 38, & 39
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)
Remove the gas control valve including air inlet cowl; refer to
section 9.3.
d)
Unscrew the three screws holding the lower section of the
black plastic air inlet cowl and gas valve mounting plate, remove
plate and cowl; refer to Figures 37 and 38.
e)
Unscrew the four screws holding the fan to the burner
manifold, and remove fan; refer to Figure 39.
f)
Attach and secure the replacement fan, replace the gasket.
g)
Re-assemble in reverse order; ensure that all joints and seals
are correctly re-fitted.
9.4
FAN
29
