Worcester Bosch Greenstar Ri Compact ErP regular (27Ri, 30Ri)
Regular boiler, natural gas and LPG
Combustion figures
| Figure | Natural gas (G20) | LPG (G31) |
|---|---|---|
CO₂ at high rate More infoHide infoFrom Tables 23 and 24 (MI 7.6), maximum setting, measured after 10 minutes. The technical data (MI 3.3, Table 5) gives 9.1% (NG) and 10.6% (LPG) at maximum, after 30 minutes. The MI says the gas valve is factory set and must not be adjusted during commissioning if found out of tolerance: call the Worcester help line (MI 6.6). | Between 8.5 and 10.1% | Between 9.8 and 11.1% |
CO₂ at low rate More infoHide infoFrom Tables 23 and 24 (MI 7.6), minimum setting, measured after 10 minutes. The manual contradicts itself: its worked example for NG says that with a maximum reading of 9.5% the minimum must be between 8.0% and 9.3%, but Table 23 only asks for above 7.5%. Both shown as printed. The technical data (MI 3.3, Table 5) gives 8.5% (NG) and 9.6% (LPG) at minimum, after 30 minutes. | A minimum 0.2 lower than the maximum reading taken but above 7.5% | A minimum 0.2 lower than the maximum reading taken but above 8.5% |
Maximum CO More infoHide infoThe manual gives several limits. The combustion check flow chart (MI 6.6, Fig. 51) says CO < 350ppm at maximum and minimum rate. Tables 23 and 24 (MI 7.6) give less than 200ppm at maximum and less than 50ppm at minimum, but the steps above them in MI 7.6 say to check CO is less than 200ppm at both maximum and minimum. All shown as printed. |
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CO/CO₂ ratio More infoHide infoFrom the combustion check flow chart (MI 6.6, Fig. 51), at maximum and minimum rate. Tables 23 and 24 (MI 7.6) don’t give a ratio. | < 0.004 | < 0.004 |
O₂ | Not given in MI | Not given in MI |
Working inlet pressure More infoHide infoFrom Figs. 49 and 50 (MI 6.5.1), boiler running at maximum in service mode. At the meter: NG 19–23 mbar. At the regulator: LPG 32–45 mbar. The pressure at the boiler must not be less than the meter pressure minus 1 mbar (NG) or minus 2.5 mbar (LPG), and the drop from the meter or regulator to the gas valve must be no more than 2.5 mbar (NG) or 4 mbar (LPG). |
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Gas rate at maximum More infoHide infoMax. 10 minutes from lighting, NG figures for G20 (MI 3.3, Table 5, where the sizes are headed 27kW and 30kW). Measure at the gas meter after 10 minutes at maximum output (MI 6.5.2). Where there’s no gas meter (e.g. LPG), check CO/CO₂ against the settings in MI 7.6 instead. |
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Flue integrity More infoHide infoAt the air intake sample point on the flue turret, boiler case on, boiler running at maximum output, readings allowed to stabilise (MI 7.3). Readings outside these limits mean a problem with the flue system or combustion circuit, e.g. missing or dislodged seals. | O₂ ≥ 20.6% CO₂ < 0.2% | O₂ ≥ 20.6% CO₂ < 0.2% |
From 6 720 813 282 (2015/07)
Enter service mode for high and low rate
High rate
- Lower the control panel to the service position and remove the installer access cover to reach the service button.
- Hold the service button for more than 5 seconds. The red LED flashes.
- Turn the control knob to max. The red LED flashes in a five-flash sequence.
Low rate
- Turn the control knob to min. The red LED flashes in a two-flash sequence.
- Turn the knob back to max to return to maximum.
Ending the test
- Press the service button briefly to come out. The LED stops flashing.
Models and GC numbers
| Model | GC number | Gas |
|---|---|---|
| 27Ri Compact ErP | 41-406-54 | NG |
| 30Ri Compact ErP | 41-406-56 | NG |
| 27Ri Compact ErP LPG | 41-406-55 | LPG |
| 30Ri Compact ErP LPG | 41-406-57 | LPG |
Source: Greenstar Ri Compact ErP wall hung RSF gas fired condensing regular boiler installation, commissioning and servicing instructions, 6 720 813 282 (2015/07).
Sections: Cover (GC numbers); 3.3 Technical data; 6.4.1 Setting the appliance to service mode; 6.5 Commissioning; 6.5.1 Checking the gas inlet pressure; 6.5.2 Checking the gas rate and pressure; 6.6 CO and combustion checks; 7.2 Checking the gas inlet pressure; 7.3 Checking flue integrity; 7.5.1 Setting the boiler to maximum; 7.6 Flue gas analysis.
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.