Ideal Logic System (15, 18, 24, 30)
System boiler, natural gas
Combustion figures
| Figure | Natural gas (G20) |
|---|---|
CO₂ at high rate More infoHide infoThe MI says the combustion is checked, adjusted and preset at the factory, and the air/gas ratio valve must not be adjusted. It gives CO and CO/CO₂ ratio limits only. | Not given in MI |
CO₂ at low rate | Not given in MI |
Maximum CO More infoHide infoSame limit at maximum and minimum rate (commissioning flowchart). Set the boiler to maximum, allow combustion to stabilise, then check at the flue gas sampling point. Minimum rate is set with the CH temperature knob (shows S on the display, stays at minimum for 5 minutes). | Less than 350 ppm |
CO/CO₂ ratio More infoHide infoSame limit at maximum and minimum rate (commissioning flowchart). The servicing schedule says contact Ideal if the ratio is greater than 0.004 once flue integrity, seals, inlet pressure and gas rate have been checked. | Less than 0.0040 |
O₂ | Not given in MI |
Working inlet pressure More infoHide infoCheck at maximum rate at the inlet pressure test point on the gas service cock. Gas supply is G20, 20 mbar. Minimum at the meter outlet: 19 mbar. The MI says the 1:1 gas valve gives full output down to 14 mbar inlet, and that the gas cock can reduce the pressure further when measured at its test point (graph of pressure drop against heat input on MI p. 8). |
|
Gas rate at maximum More infoHide infoGas consumption from Table 2, using a gross CV of 38.7 MJ/m³. At minimum: 0.500 m³/h (15, 18, 24) and 0.622 m³/h (30). |
|
Flue integrity More infoHide infoAt the air inlet test point, boiler at maximum. The flowchart asks whether O₂ is 20.6% or more OR CO₂ is 0.2% or less. | O₂ ≥ 20.6% CO₂ ≤ 0.2% |
From UIN 205552 A05 (January 2014)
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 |
|---|---|---|
| Logic System 15 | 41-750-24 | NG |
| Logic System 18 | 41-750-25 | NG |
| Logic System 24 | 41-750-26 | NG |
| Logic System 30 | 41-750-27 | NG |
Source: Ideal Logic System 15, 18, 24, 30 installation and servicing, UIN 205552 A05 (January 2014).
Sections: Table 1 General data; Table 2 Performance data; Gas supply (p. 8); 29 Commissioning and testing; 30 Initial lighting; 34 Servicing schedule; 65 and 68 Fault finding; Flowchart for CO level and combustion ratio check on commissioning a condensing boiler, including setting to minimum rate (pp. 58–59).
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.