Baxi ECOGEN 24/1.0, Installation & Servicing Instructions Manual

Page: 67 / 94

Fig. 74
page 67
15.0 Combustion Check
15.1 Checking 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 activate the chimney sweep function by pressing and holding the easy menu and menu buttons (
Fig. 74a ) whilst in the normal operation
screen until chimney sweep function option appears. Press the Selector Button to switch the chimney sweep function on.
3. The Selector Button will show Chimney Sweep Function on. Chimney Sweep function Burner Output Adjust 'Engine burner min' appears.
Press the Selector Button. Engine burner min will flash.
Use the wheel to scroll through the six options
a) Engine burner minimum
b) Engine burner maximum
c) Supplementary burner minimum
d) Supplementary burner maximum
e) Engine and Supplementary burners minimum
f) Engine and Supplementary burners maximum
Choose the single maximum operation b) or d) and press to confirm your choice. The burner will fire and remain at maximum rate unless a fault condition occurs or the set boiler
flow temperatures is attained when the burners will turn off.
NOTE: The boiler set flow temperature is set to 90° to avoid interruption of the rate measurement.
4. After 1 minute remove the plug from the flue adaptor test point. Insert the analyser probe and allow time for the reading to settle ( Fig. 75 ).
The CO2 should be 9.0% ± 0.3 for the supplementary
The CO2 should be 9.0% ± 0.3 for the engine
Propane Gas ­ When either burner is tested individually at maximum rate: The CO2 should be 10.2% ± 0.3.
5.
It is possible to alter the CO2 at the maximum rate by adjustment of the gas valve. Remove the blue plastic cover from the 'Throttle' adjustment screw.
At maximum rate the 'Throttle' adjustment screw should be turned, using a suitable 2.5mm hexagon key, until the correct reading is obtained (
Fig. 76 ).
Turning clockwise will reduce the CO2. Anti­clockwise will increase the CO2
6.
The CO2 must then be checked at minimum rate.
The CO2 should be 8.7% ± 0.3 for the supplementary
The CO2 should be 8.8% ± 0.3 for the engine
Propane Gas ­ CO2 at minimum rate:­
The CO2 should be 9.6% ± 0.3 for the supplementary
The CO2 should be 9.8% ± 0.3 for the engine
The CO2 levels at the minimum rate must always be less than those measured for the maximum rate ­ see section 15.2. 'Using a Combustion Analyser to adjust the valve offset'
paragraph 3a . If there appears to be a problem refer to section 15.2.
7. The 'Calibration Function' is maintained for 20 minutes unless the maximum CH temperature is exceeded. The function can be disabled at any time by repeating paragraph
2.