Baxi 600 Combi 2 (624-2, 630-2, 636-2)
Combi, natural gas and LPG
Combustion figures
| Figure | Natural gas (G20) | LPG (G31) |
|---|---|---|
CO₂ at high rate More infoHide infoNG: chimney sweep high mode H; MI says remove the boiler door to take measurements or make adjustments (MI 7.2.6). NG values are for G20 only: for G20 + 20% H₂ the MI says to calibrate by O₂%, but it gives no NG O₂ figures. LPG: nominal and range of tolerance, frontal panel closed (MI 7.2.4). | 8.8 to 9.4% |
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CO₂ at low rate More infoHide infoNG: chimney sweep low mode L, G20 only (MI 7.2.6). LPG: frontal panel closed (MI 7.2.4). | 8.1 to 8.6% |
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Maximum CO More infoHide infoAt maximum and minimum rate (MI 7.2.5). | < 350 ppm | < 350 ppm |
CO/CO₂ ratio More infoHide infoAt maximum and minimum rate (MI 7.2.5, 10.1). | < 0.004 | < 0.004 |
O₂ at high rate More infoHide infoLPG figures copied as printed (MI 7.2.4, frontal panel closed). The printed ranges look odd: the 36 Combi nominal sits at the end of its range. | Not given in MI |
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O₂ at low rate More infoHide infoLPG figures copied as printed (MI 7.2.4, frontal panel closed). | Not given in MI |
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Working inlet pressure More infoHide infoBoiler at maximum rate (chimney sweep). MI text says at least 17.5 mbar NG or 29.5 mbar LPG at the inlet gas pressure test point. At the meter: NG 18.5–23 mbar. At the LPG storage vessel: 32–45 mbar. Supply pressure in the gas category table: NG 20 mbar, LPG 37 mbar (MI 3.1.3). |
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Gas rate at maximum More infoHide infoWith other appliances and pilot lights off (MI 7.2.1). The technical data (MI 3.1.5) gives the same figures. |
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Flue integrity More infoHide infoAt the air inlet test point, boiler at maximum rate (MI 7.2.5, 10.1). | O₂ ≥ 20.6% CO₂ < 0.2% | O₂ ≥ 20.6% CO₂ < 0.2% |
From 7875578-02 (07/24)
Enter service mode for high and low rate
High rate
Low rate
Models and GC numbers
| Model | GC number | Gas |
|---|---|---|
| 624-2 (24 Combi) | 47-077-55 | NG |
| 630-2 (30 Combi) | 47-077-56 | NG |
| 636-2 (36 Combi) | 47-077-57 | NG |
Source: Baxi 400 Combi 2.1, 600 Combi 2, 800 Combi 2, Assure 500 Combi 2 Installation and Service Manual & Boiler Fiche, 7875578-02 (07/24).
Sections: 3.1.2 Certifications; 3.1.3 Gas category; 3.1.5 Technical information; 7.2.1 Checking the working gas inlet pressure and gas rate; 7.2.2 Combustion parameters; 7.2.3 Activating the chimney sweep mode; 7.2.4 LPG conversion procedure; 7.2.5 Commissioning procedure; 7.2.6 Adjusting the gas valve; 10.1 General; 11.6.13 Setting an uncalibrated gas valve.
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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.