Checking The Co; Combustion Check - Potterton Gold 24 HE Installation & Service Instructions Manual

13.0 COMBUSTION CHECK

13.1

Checking the CO

2
1. The combustion (CO ) may be checked using a
2
suitably calibrated analyser after running the boiler
for several minutes.
2. To do this it is necessary to set the boiler to
'Calibration Mode'.
3. Ensure that all external controls are calling for
heat. The actual current boiler temperature is shown
on the display.
4. Turn both temperature control knobs fully
anticlockwise, then quickly turn the DHW
temperature knob 1 / clockwise twice and back fully
4
anticlockwise (Fig. 70).
5. The display will now alternate between 'SF' and
the current boiler temperature and both green LEDs
will flash (Figs. 71 & 72).
6. Turn the CH temperature knob fully clockwise. As
the knob is turned the display will change, indicating
the fan speed.
7. The display will show '00', indicating maximum
rate, then revert to 'P ' alternating with the current
boiler temperature (Figs 73,74 & 75).
8. Remove the plug from the flue adaptor test point.
Insert the analyser probe and allow time for the
reading to settle (Fig. 76).
The CO should be 8.7% ± 0.2
2
9. It is possible to alter the CO
gas valve. Remove the cover from the 'Max. Rate'
adjustment screw. At maximum rate the 'Max. Rate'
adjustment screw should be turned, using a suitable
hexagon key, until the correct reading is obtained
(Fig. 77).
10. The CO must then be checked at minimum rate.
2
Turn the CH temperature knob fully anticlockwise. As
the knob is turned the display will change, indicating
the fan speed. When the display reads ' 0' the boiler
runs at minimum rate.
The CO should be 8.4% ± 0.2.
2
11. With the boiler on minimum, the 'Min. Rate'
adjustment screw must be altered, using a suitable
hexagon key, after removing the cap (Fig. 77). If the
CO is reset at either boiler rate it must be rechecked
2
at the other rate and also adjusted if required.
12. 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 DHW knob.
Publication No. 5116282
by adjustment of the
2
Adjustment
(cap fitted)
Central Heating
Temperature Control
Display
Selector Switch
Reset
Central Heating
Temperature Control
Fig. 71
Fig. 73
Flue Adaptor
Test Point
Plug
Analyser Probe
Min Rate
Screw
Domestic Hot Water
Fig. 70
Temperature Control
2
bar
Domestic Hot Water
Temperature Control
Fig. 72
Fig. 74
Fig. 76
Max Rate
Adjustment Screw
(cover removed)
Fig. 77
x 2
0
GRASSLIN
Fig. 75
Gas Valve
43