Baxi Potterton Gold HE A Range manual Combustion Check, Checking the CO2

x 2

Central Heating			Domestic Hot Water
Temperature Control		Fig. 105	Temperature Control
Selector Switch	Display
				2		1	12
				3			11
				4				10
Reset			2	5				9
				PM
			3					8
				7				7
				8				AM
			￿0 4	9			0	5
			bar	10				4
				11			3
				12	1		2
	Central Heating		Domestic Hot Water
Temperature Control			Temperature Control

Fig. 106 Fig. 107

Fig. 108 Fig. 109 Fig. 110

Flue Adaptor Test

Point

Plug

Analyser Probe

Fig. 111

	Max Rate
	Adjustment Screw
Min Rate	(cover removed)
Adjustment Screw
(cap fitted)

Gas Valve

Fig. 112

15.0Combustion Check

15.1Checking the CO2

IMPORTANT: The CO2 must only be checked and adjusted if a suitable calibrated combustion analyser is available.

1.The combustion (CO2) may be checked using a 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 1/4 clockwise twice and back fully anticlockwise (Fig. 105).

5.The display will now alternate between ‘SF’ and the current boiler temperature and both green LEDs will flash (Figs. 106 & 107).

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 108, 109 & 110).

8.Remove the plug from the flue adaptor test point. Insert the analyser probe and allow time for the reading to settle (Fig. 111).

The CO2 should be 8.7% ± 0.2

9.It is possible to alter the CO2 by adjustment of the gas valve. Remove the plastic 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. 112). Turning clockwise will reduce the CO2. Anticlockwise will increase the CO2.

10.The CO2 must then be checked at minimum rate. 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 CO2 should be 8.4% ± 0.2.

11.With the boiler on minimum, the ‘Min. Rate’ adjustment screw must be altered, using a suitable hexagon key, after removing the cap (Fig. 112). If the CO2 is reset at either boiler rate it must be rechecked 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.

© Baxi Heating UK Ltd 2008 49