Alpha InTec² XE combi (25XE, 28XE)
Combi, natural gas (LPG by conversion)
Combustion figures
| Figure | Natural gas (G20) | LPG (G31) |
|---|---|---|
CO₂ at high rate More infoHide infoMI gives this as CO₂ at maximum CH output, the figure checked in chimney sweep mode with the CH knob at maximum, front case fitted. MI also gives CO₂ at maximum DHW output (the 99% setting used in the CO₂ set up procedure): NG 25XE 9.2%, 28XE 9.1% (± 0.8); LPG 10.2% both sizes (± 1). CO₂ at medium output (ignition), checked with the display at 72 (25XE) or 56 (28XE): NG 9.0% both sizes (± 0.8); LPG 10.7% both sizes (± 1). NG tolerance printed as Factory set CO₂ (± 0.8%); LPG as % (±1%). |
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CO₂ at low rate More infoHide infoMI gives this as CO₂ at minimum output, checked with the CH knob at minimum after the self-diagnosis symbol stops flashing. LPG table prints 10.0 for 25XE and 10 for 28XE. | 9.0% ± 0.8 | 10.0% ± 1 |
Maximum CO More infoHide infoPrinted as CO (max) in the NG table. The LPG table says other technical data is the same as NG data. | 200 ppm | 200 ppm |
CO/CO₂ ratio More infoHide infoPrinted as Maximum CO/CO₂ in the NG table; the LPG table says other technical data is the same as NG data. Section 6 says to investigate if the measured ratio is greater than 0.003. | 0.003 | 0.003 |
O₂ | Not given in MI | Not given in MI |
Working inlet pressure More infoHide infoPrinted as Gas supply pressure in the technical data, with no range. Measurement point not stated in MI. Section 6 says to check the working gas inlet pressure at maximum rate; the gas valve has an inlet pressure test point (Fig. 5.2). | 20 mbar | 37 mbar |
Gas rate at maximum More infoHide infoNG printed as Gas rate at max. output. The LPG table prints it just as Gas rate. |
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From Part No. 1.038088 rev. ST.001590/000 0315/D343
Enter service mode for high and low rate
High rate
- Keep the front case fitted. With no heating or hot water demand, hold RESET for 8 seconds.
- The parasol and snowman symbols flash together. A Climatic controller, if fitted, shows ERR>07. That’s not a fault.
- Turn the central heating knob to maximum. Display shows 99.
Low rate
- Turn the central heating knob to minimum. Display shows 00.
- For the medium (ignition) check, turn the knob until the display shows 72 (25XE) or 56 (28XE).
Ending the test
- Turn the boiler off to come out. It also ends by itself after 15 minutes.
Models
| Model | Gas |
|---|---|
| InTec² 25XE | NG |
| InTec² 28XE | NG |
Source: Alpha InTec² 25XE and 28XE Installation and Servicing Instructions, Part No. 1.038088 rev. ST.001590/000 0315/D343.
Sections: 2.1 Technical performance data; 2.6 Data badge annotation; 5.3 Test for gas tightness and purge the supply; 5.7 Checking the combustion - chimney sweep mode; 5.12 Converting the boiler to operate on LPG; 5.13 CO2 set up procedure; 5.14 Programming the PCB; 6 Routine servicing (combustion check).
Spotted something wrong? Tell us.
Check these figures against the MI for the appliance in front of you, matched by GC number and manual date. Combustion work needs a calibrated analyser and a Gas Safe registered engineer.