Glow-worm Betacom 4 combi (24c -A, 30c -A)
Combi, natural gas
Combustion figures
| Figure | Natural gas (G20) |
|---|---|
CO₂ at high rate More infoHide infoCheck programme P.01 set to 100, wait 5 minutes for a stable reading, measure at the flue gas analysis point. The check figure (MI 7.9.5 and 11.4) is given for front casing on / front casing off. The setting figure is the CO₂ at full load in the Setting the CO₂ value table (MI 11.5); the text there says the value is with the front casing removed, while the table heading says front casing on / front casing off. |
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CO₂ at low rate | Not given in MI |
Maximum CO More infoHide infoThe MI gives two different limits: ≤ 250 ppm at full load in the Setting the CO₂ value table (MI 11.5), and less than 350 ppm at maximum and minimum rate in the combustion chart (Appendix I). One box in the chart (after checking seals) says less than 335 ppm. |
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CO/CO₂ ratio More infoHide infoThe MI gives two different limits: ≤ 0.0027 in the Setting the CO₂ value table (MI 11.5), and less than 0.004 at maximum and minimum rate in the combustion chart (Appendix I). |
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O₂ at high rate More infoHide infoO₂ at full load, from the Setting the CO₂ value table (MI 11.5). | 4.5 ±1.8 vol. % |
O₂ at low rate | Not given in MI |
Working inlet pressure More infoHide infoMeasured at the measuring nipple on the gas isolator cock, boiler at full load (check programme P.01 with an eBUS controller, or P.03 without). MI prints 1.7 ... 2 kPa (17.0 ... 20 mbar). Technical data gives G20 gas supply pressure 20 mbar. |
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Gas rate at maximum More infoHide infoGas flow at P max, hot water (G20), from Technical data. MI 7.9.1 also gives a table of gas rates by the Qnw on the data plate, measured at the gas meter after 5 minutes on P.01: for 24.7 kW nominal 2.61 m³/h (+5% 2.74, −10% 2.35); for 30.6 kW nominal 3.24 m³/h (+5% 3.40, −10% 2.92). |
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Flue integrity More infoHide infoAt the air inlet test point, boiler at maximum rate (combustion chart, Appendix I). | O₂ ≥ 20.6% CO₂ < 0.2% |
From 0020238424_02 – 15.11.2017
Enter service mode for high and low rate
High rate
Low rate
Models and GC numbers
| Model | GC number | Gas |
|---|---|---|
| Betacom 4 24c -A (H-GB) | 47-019-52 | NG |
| Betacom 4 30c -A (H-GB) | 47-019-53 | NG |
Source: Glow-worm Betacom 4 24c -A, 30c -A installation and maintenance instructions, 0020238424_02 – 15.11.2017.
Sections: 2.3 Validity of the instructions; 7.9.1 Checking the gas flow rate; 7.9.2 Checking the gas connection pressure (gas flow pressure); 7.9.3 Checking the leak-tightness of the flue gas installation and flue gas recirculation; 7.9.5 Checking the CO₂ content; 11.4 Checking the CO₂ content; 11.5 Setting the CO₂ content; Appendix A Check programmes; Appendix I Combustion chart; Appendix K Technical data.
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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.