COMBI A - Instruction Manual

14. Commissioning and

14. Commissioning and testing (continued) 14.3 Adjusting the CO2 1. Remove the casing panel as described in Section 18.1 (page 43); 2. Connect a manometer to the inlet test nipple on the gas valve, turn on a hot tap and ensure the inlet working pressure is 20mbar. If correct proceed as follows; 3. Turn on the combustion analyser, remove the combustion test point plug Q (Fig. 36) and insert the analyser probe into the test point; 4. Turn on a hot tap and ensure that the boiler is firing. 5. Access the setting menu by pressing the and keys for 5 seconds the icon will be shown in the display; 6. Press the menu button four times to access Menu 5 and press the setting button once to switch the output of the boiler to maximum (two digits will be flashing indicating the temperature of the boiler). There will be a cursor at the top of the display indicating the boiler is at maximum output. If the cursor is at the bottom of the display (indicating minimum output) press the button the change to maximum output; 7. If necessary adjust the screw on the gas valve (Fig. 37) to set the CO2 to 8.9% +/- 0.2% (NG) or 9.7% +/- 0.2% (LPG); 8. Press the setting button once to set the combustion control rate mode to minimum, and, if necessary, adjust the screw on the gas valve to set the CO2 to 8.9% +/- 0.2% (NG) or 9.7% +/- 0.2% (LPG); 9. Press the setting button again to set the combustion rate control mode to maximum and if necessary adjust the screw on the gas valve to set the CO2 to 8.9% +/- 0.2% (NG) or 9.2% +/- 0.2% (LPG); 10. Reassemble in reverse order. 14.4 Gas Conversion To convert from Natural Gas (G20) to LPG (G31), it is necessary to insert a diaphragm and restrictor between the gas valve and air/gas arm. Once the conversion has been made, the CO2 setting will need to be checked as described in Section 14.3, for LPG the CO2 reading should be 10% +/- 0.2% with the front case fitted). To convert from LPG (G31) to Natural Gas (G20), it is necessary to remove the diaphragm and restrictor from between the gas valve and air/gas arm. Once the conversion has been made, the CO2 setting will need to be checked as described in Section 14.3, for NG the CO2 reading should be 9.2% +/- 0.2% (with the front case fitted). Fig. 37 Test nipple Adjustment screw Fig. 36 Q 14.5 Range rating the maximum heating power To adjust the maximum heating power it is necessary to access the settings menu by pressing the and buttons together for five seconds, and proceed as follows; 1. Press the menu button 3 times to access Menu 4; 2. Press the button to access Menu 4.9; 3. The value is adjustable between 0 and 10, 0 being the minimum output and 10 being the maximum, please refer to the chart on page 33 (Fig. 40) for the required setting; 4. The maximum central heating output can now be adjusted by pressing the setting button ; 5. To exit the setting mode, do not press any buttons for 1 minute, the boiler will automatically exit the Setting Menu. 14.6 Fitting the external sensor The external sensor should be fitted 1.5 meters above the floor on a North to North West facing wall, out of direct sunlight. To connect the external sensor, it is first necessary to remove the casing panel as described in Section 18 (page 42); Remove the PCB cover as described in Section 18.4 and connect the external sensor as described in Section 18.5 (page 50). 30

14.7 External sensor set-up (where fitted) When using an outdoor sensor, the microprocessorcontrolled PCB will select the most suitable flow temperature, taking into account the external temperature and the type of system. The microprocessor is capable of doing this because it is possible to establish a link between the external temperature and the flow temperature of the Central Heating system water. This link translates into a “thermal curve”. The type of curve should be chosen in correspondence with the planned temperature of the system and the nature of the heat loss present in the building. To set up the external sensor, proceed as follows; 1. Access the settings menu by pressing the and buttons for five seconds; 2. Press the button 5 times to access Menu 6; 3. Press the button, the 3rd and 4th digits will flash; 4. Press the or buttons to change from 1 (sensor not fitted ) to 0 (sensor fitted) and press the button again to select the change; 5. Select the thermal curve required from Table D; 6. Press the or buttons to change to Menu 6.2; 7. To adjust the thermal curve, press the button, the 3rd and 4th digits will begin to flash; 8. Press the or buttons to select the parameter that best meets your temperature requirement shown in Table D; 9. Once the correct parameter has been set, press the button again to confirm the selection . TABLE D CONVECTOR RADIATOR - CURVES 2.5 TO 3 STEEL RADIATOR - CURVES 1.5 TO 2 OVERSIZED STEEL RADIATOR - CURVES 1 TO 1.2 UNDERFLOOR HEATING - CURVES 0.3 TO 0.5* *WHERE CURVE 0.3 OR 0.5 ARE SELECTED, A SYSTEM SAFETY THERMOSTAT MUST BE CONNECTED TO THE MAIN PCB TERMINAL 14 (SEE FIG. 29, PAGE 26). NOTE: DO NOT FIT THE EXTERNAL SENSOR IN THE EVENT THAT THE BOILER IS BEING USED TO HEAT AN INDIRECT HOT WATER STORAGE CYLINDER. 14.8 Setting the parallel shift In the event that the thermal curve set is giving too high or too low a temperature, there are two options, you can either alter the thermal curve as described in Section 14.7 or adjust the parallel shift of the curve. To adjust the parallel shift, proceed as follows: 1. Access the settings menu by pressing the and buttons together for five seconds; 2. Press the button 5 times to access Menu 6; 3. Press the or buttons to access Menu 6.3; 4. Press the button, the 3rd and 4th digits will flash; 5. Press the or buttons to adjust the parallel shift up and down in steps of 1 between 0 and 20 (see Table E). 14.9 Completion For the Republic of Ireland it is necessary to complete a “Declaration of Conformity” to indicate compliance to I.S.813. An example of this is given in the current edition of I.S.813. In addition it is necessary to complete the Commissioning Checklist in Section 24 of this manual (Page 60). TABLE E As part of the commissioning process, it is a legal requirement to register all boiler installations or replacements with CORGI. 31