Combustion Check; Setting The Gas Valve - Baxi Platinum Combi 24 HE A Installation & Servicing Instructions Manual

Central Heating
Temperature Control
Display
Selector Switch
Central Heating
Temperature Control
Fig. 94
Fig. 96
Flue Adaptor Test
Point
Plug
Analyser Probe
Offset
Adjustment Screw
(cap fitted)
Reduce CO Increase CO
2 2
at min. rate
at min. rate
If the CO is reset at minimum
2
rate it must be rechecked at
maximum rate again and adjusted
if required. If the CO is reset at
2
maximum rate it must be
rechecked at minimum rate and
adjusted if required.
© Baxi Heating UK Ltd 2014
Domestic Hot Water
Fig. 93
Temperature Control
2
1
3
0 4
bar
Domestic Hot Water
Temperature Control
Fig. 95
Fig. 97
Fig. 99
Adjustment Screw
(cover removed)
Reduce CO
at max. rate
Fig. 100
Gas Valve
Do not turn the adjustment
screws more than 1/8 of a turn at
a time. Allow the analyser reading
to settle before any further
adjustment
x 2

15.0 Combustion Check

15.1
IMPORTANT: The CO
adjusted to set the valve if a suitable calibrated
combustion analyser is available, operated by a
competent person - see Section 13.1
1. The combustion (CO
boiler for several minutes. To do this it is necessary to set
the boiler to 'Calibration Mode'.
2. Ensure that all external controls are calling for heat. The
actual current boiler temperature is shown on the display.
0
GRASSLIN
3. Turn both control knobs fully anticlockwise, then quickly
turn the right hand knob
anticlockwise (Fig. 93).
4. The display will now alternate between 'SF' and the
current boiler temperature and both green LEDs will flash
(Figs. 94 & 95).
5. Turn the left hand knob fully clockwise. As the knob is
turned the display will change, indicating the fan speed.
6. The display will show '00', indicating maximum rate, then
revert to 'P ' alternating with the current boiler temperature
(Figs. 96, 97 & 98).
7. Remove the plug from the flue sampling test point. Insert
the analyser probe and allow sufficient time for the reading
to settle (Fig. 99).
Fig. 98
8. It is possible to alter the CO
valve. Remove the plastic cover from the Throttle
Adjustment Screw. At maximum rate the Throttle
Adjustment Screw should be turned, using a suitable
hexagon key, until the correct reading is obtained (Fig. 100).
Turning clockwise will reduce the CO
increase th e CO
9. The CO
the left hand knob fully anti-clockwise. As the knob is turned
Throttle
the display will change, indicating the fan speed. When the
display reads ' 0' the boiler runs at minimum rate.
10. With the boiler on minimum, the Offset Adjustment
Screw must be altered, using a suitable hexagon key, after
Increase CO
2 2
removing the cap (Fig. 100). Turning anti-clockwise will
at max. rate
reduce the CO
11. The 'Calibration Function' is maintained for 20 minutes
unless the maximum CH temperature is exceeded. The
function can be disabled at any time by turning the right
hand knob.
12. Check the Combustion Performance (CO/CO
This must be less than 0.004.

Setting the Gas Valve (

CO check)
2
must be only be checked and
2
) may be checked after running the
2
/ clockwise twice and back fully
1
4
The CO should be 8.7% ± 0.2
2
by adjustment of the gas
2
. Anticlockwise will
2
.
2
must then be checked at minimum rate. Turn
2
The CO should be 8.4% ± 0.2
2
. Clockwise will increase th e CO
2
.
2
ratio).
2
49