British Gas ICS1 system (ZSBR 7-28, ZSBR 11-28)
System boiler, natural gas and LPG
Combustion figures
| Figure | Natural gas (G20) | LPG (G31) |
|---|---|---|
CO₂ at high rate More infoHide infoAt max. rated heat output, set with service function 2.0 Operating mode on Max. No tolerance given in MI. Same figures in Table 2 (MI 1.9) and Table 14 (MI 8.1). | 9.2% | 10.8% |
CO₂ at low rate More infoHide infoAt min. rated heat output, set with service function 2.0 Operating mode on Min. No tolerance given in MI. | 8.8% | 10.5% |
Maximum CO | Not given in MI | Not given in MI |
CO/CO₂ ratio | Not given in MI | Not given in MI |
O₂ | Not given in MI | Not given in MI |
Working inlet pressure More infoHide infoMeasured at the gas supply pressure testing point (item 7, on the gas valve). The MI says natural gas boilers must not be run below 18 mbar or above 24 mbar (nominal 20 mbar), and LPG boilers must not be run if the supply pressure is not 37 mbar. MI 5.1 words the LPG figure as at the inlet to the appliance. |
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Gas rate at maximum More infoHide infoAfter 10 minutes from lighting. NG G20 (CVnet 34.02 MJ/m³), LPG (CVnet 88 MJ/m³). | 2.9 m³/h | 2.1 kg/h |
Flue integrity More infoHide infoAt the combustion air testing point (234.1), in chimney sweep mode, for C13 or C33 flue systems. The MI says O₂ must not be less than 20,6% and CO₂ must not exceed 0,2%. | O₂ ≥ 20.6% CO₂ ≤ 0.2% | O₂ ≥ 20.6% CO₂ ≤ 0.2% |
From 6 720 610 603 GB (03.02)
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 |
|---|---|---|
| ZSBR 7-28 ICS1 | 41-108-04 | NG |
| ZSBR 11-28 propane | Not added yet | LPG |
Source: ICS1 Installation and Servicing Instructions, wall mounted condensing boiler for central heating, 6 720 610 603 GB (03.02).
Sections: 1.6 Layout of appliance; 1.7 Function; 1.9 Technical data; 5.1 Commissioning; 8 Converting the appliance to different gas types (Checking the gas supply pressure); 8.1 Setting the gas/air ratio; 8.2.1 Testing the O2 or CO2 level in the combustion air; 8.2.2 Testing CO and CO2.
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.