32
10.6.2 GAS VALVE MINIMUM SETTING
Locate and gently turn the HTG trimmer till the minimum
value (fan speed) is obtained and check that it corre-
sponds with the appropriate CO
2
value (Minimum) for
the respective appliance. If the CO
2
reading is correct,
rotate the HTG trimmer until the correct value is obtained
for the respective appliance (see fan speed table) and
proceed to 7.4.3.
However, if the CO
2
reading is incorrect, the minimum
gas pressure must be adjusted as follows:
Using a 2,5mm Allen key, very slowly turn the minimum
adjustment screw (see fi g. 45) – clockwise to increase,
counter clockwise to decrease - until the correct value
is displayed on the CO
2
analyser (allow time for the
analyser to stabilise).
10.6.3 COMPLETION
On completion of the combustion analysis check and/or
any gas valve adjustment, set the HTG trimmer to the
corresponding value as detailed in the fan speed table.
Move the mode selector to the OFF position. Remove
the test probe from the test point and refi t the sealing
screw/s and/or cap.
Refi t the PCB cover and refi t the appliance casing as
detailed in 4.7
IMPORTANT
A GAS TIGHTNESS CHECK MUST BE CARRIED OUT
IF ANY GAS CARRYING COMPONENTS HAVE BEEN
REMOVED, REPLACED, OR DISTURBED .
10.7 COMBUSTION ANALYSIS TEST
A combustion analysis check can easily be carried out
on the appliance via the test points located on the top of
the appliance (see 7.4).
IMPORTANT
There are 2-sets of CO
2
values for the appliance, i.e.
a value for the casing ‘on’ and a value for the casing
‘off’.
Use the CO
2
values for ‘casing-on’ when you are
carrying out a combustion analysis check.
●
Insert the fl ue gas analyser probe into the fl ue gas test
point (see fi g. 37).
●
Operate the boiler at full output and compare the values
with those shown in section 10 (LPG). If different adjust
the gas valve according to the above.
10.8 APPLIANCE FAN SPEEDS
The appliance fan speeds require to be checked and/
or adjusted prior to making any adjustments to the gas
valve or if the main PCB has been replaced.
ATTENTION
Gas type and appliance fan speed (output)
must be set
according to the specifi c appliance specifi cation. Vokera
accepts no responsibility if the gas type and/or fan speed
is not correctly adjusted according to the respective ap-
pliance specifi cation as detailed on the appliance data
badge.
10.8.1 ADJUSTING THE APPLIANCE FAN SPEEDS
Move the selector switch to the OFF position; remove the
casing as detailed in 4.7.
10.8.2 ABSOLUTE MAX FAN SPEED
Locate the MAX trimmer (fi g. 43) and gently adjust clock-
wise or counter clockwise to achieve the correct fan speed
(see table above).
NOTE
The display shows the fan RPM in multiples of 100, i.e.
25 = 2500RPM.
10.8.3 ABSOLUTE MIN FAN SPEED
Locate the MIN trimmer (fi g. 43) and gently adjust clock-
wise or counter clockwise to achieve the correct fan speed
(see table above).
NOTE
The display shows the fan RPM in multiples of 100, i.e.
25 = 2500RPM.
10.8.4 IGNITION FAN SPEED
Locate the IGN trimmer (fi g. 43) and gently adjust clock-
wise or counter clockwise to achieve the correct fan speed
(see table above).
NOTE
The display shows the fan RPM in multiples of 100, i.e.
25 = 2500RPM.
7.3.5 HEATING FAN SPEED
Lower the controls fascia and remove the cap
(A)
on the
PCB cover (fi g. 44).
Locate the HTG trimmer and gently adjust clockwise or
counter clockwise to achieve the correct fan speed (see
table 7.3.6). NOTE, the display shows the fan RPM in
multiples of 100, i.e. 25 = 2500RPM.
CASING OFF CASING ON
CO
2
9.8%
10.0%
FAN SPEED (rpm) TABLE
MODEL MAX
MIN
HTG
IGN
15VHE
4.500
1.300
4.500 3.700
Fig. 43
Fig. 44
10.8.5 FAN SPEED TABLE
Use the following table to set the corresponding fan speeds
that are relative to the appliance you are working on.
Fig. 45
Compensation
pipe connection
Minimum
screw
Maximum
screw
A