Baxi Baxi 600 Combi (624, 630, 636)
Combi, natural gas and LPG
Combustion figures
| Figure | Natural gas (G20) | LPG (G31) |
|---|---|---|
CO₂ at high rate More infoHide infoMI prints these as 9.0 + 0.3 – 0.2 and 10.5 + 0.5 – 0.1 (% maximum), the same for all three sizes. Checked in calibration mode after running the boiler for several minutes, case front panel fitted. | 9.0% +0.3 / −0.2 | 10.5% +0.5 / −0.1 |
CO₂ at low rate More infoHide infoMI prints these as 8.5 + 0.1 – 0.4 and 10.0 + 0.1 – 0.5 (% minimum), the same for all three sizes. | 8.5% +0.1 / −0.4 | 10.0% +0.1 / −0.5 |
Maximum CO More infoHide infoAt maximum and minimum rate, from the combustion procedure flow chart (Fig.47). The MI says all data are the same for NG and LPG unless stated otherwise. | < 350 ppm | < 350 ppm |
CO/CO₂ ratio More infoHide infoAt maximum and minimum rate. | < 0.004 | < 0.004 |
O₂ | Not given in MI | Not given in MI |
Working inlet pressure More infoHide infoNG from Fig.43, at maximum rate; the text also says the inlet pressure at the gas inlet test point must be at least 18 mb. At the meter: 19–23 mbar. NG nominal inlet pressure 20 mbar. LPG: the MI gives only a supply pressure of 37 mbar (gas category table, LPG section 14.3), with no range. Measurement point not stated in MI. |
| 37 mbar |
Gas rate at maximum More infoHide infoWith any other appliances and pilot lights turned off. |
|
|
Flue integrity More infoHide infoAt the air inlet test point, boiler at maximum rate. | O₂ ≥ 20.6% CO₂ < 0.2% | O₂ ≥ 20.6% CO₂ < 0.2% |
From 7717521-03
Enter service mode for high and low rate
High rate
Steps not added yet. Follow the MI.
Low rate
Steps not added yet. Follow the MI.
Ending the test: follow the MI.
Models and GC numbers
| Model | GC number | Gas |
|---|---|---|
| 624 | 47-077-28 | NG |
| 630 | 47-077-29 | NG |
| 636 | 47-077-30 | NG |
| 624 LPG | 47-077-33 | LPG |
| 630 LPG | 47-077-32 | LPG |
| 636 LPG | 47-077-31 | LPG |
Source: Baxi Combi 624 - 630 - 636, 624 LPG - 630 LPG - 636 LPG Installation and Service Manual, 7717521-03.
Sections: 3.1.3 Gas category; 3.2.1 Technical information; 7.4.1 Check the operational (working gas inlet pressure and gas rate); 7.4.2 Checking combustion - chimney sweep mode; 9.1 General; 9.3.12 Gas valve (Setting the gas valve (CO2)); 14.3 Differences for LPG models.
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.