Baxi 400 Heat (412, 415, 418, 424, 430)
Heat only, natural gas
Combustion figures
| Figure | Natural gas (G20) |
|---|---|
CO₂ at high rate More infoHide infoFrom Setting the Gas Valve (MI 10.3.11), probe in the flue sampling point. The MI does not say whether the case should be on or off for this check. There must always be a difference of 0.4% between the maximum and minimum CO₂ readings. | 9.3% ±0.1% |
CO₂ at low rate More infoHide infoRe-check both maximum and minimum if any adjustment has been made. | 8.9% ±0.1% |
Maximum CO More infoHide infoApplies at both maximum and minimum rate (commissioning flow chart, MI 7.4.2). | < 350 ppm |
CO/CO₂ ratio More infoHide infoAt both maximum and minimum rate (MI 7.4.2, 10.1 and 10.3.11). The Technical Data table (MI 3.1) words it as up to a maximum of 0.004. | < 0.004 |
O₂ More infoHide infoThe MI gives O₂ only for the flue integrity check at the air inlet. | Not given in MI |
Working inlet pressure More infoHide infoAt the gas meter: 19–23 mbar. Checked at maximum rate; the text says at least 17 mbar at the valve and 18 mbar at the gas cock. Nominal dynamic inlet pressure 20 mbar (MI 3.1). Permissible pressure drop across system pipework ≤ 1 mbar. |
|
Gas rate at maximum More infoHide infoNatural gas G20, after 10 minutes, with any other appliances and pilot lights off. |
|
Flue integrity More infoHide infoAt the air inlet (air sampling) test point, boiler at maximum rate. | O₂ ≥ 20.6% CO₂ < 0.2% |
From 7684223-01 (06/17)
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 |
|---|---|---|
| Baxi 412 Heat ErP | 41-470-50 | NG |
| Baxi 415 Heat ErP | 41-470-51 | NG |
| Baxi 418 Heat ErP | 41-470-52 | NG |
| Baxi 424 Heat ErP | 41-470-53 | NG |
| Baxi 430 Heat ErP | 41-470-54 | NG |
Source: Baxi 400 Heat Installation and Service Manual, 7684223-01 (06/17).
Sections: 3.1 Technical Data; 7.4.1 Chimney Sweep Mode; 7.4.2 Chimney Sweep Mode - Combustion Check; 7.5.1 Check the Operational (Working) Gas Inlet Pressure; 10.1 General; 10.3.11 Setting the Gas Valve (CO2 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.