Worcester Bosch Greenstar Ri ErP regular (12Ri, 15Ri, 18Ri, 24Ri)
Regular boiler, natural gas and LPG
Combustion figures
| Figure | Natural gas (G20) | LPG (G31) |
|---|---|---|
CO₂ at high rate More infoHide infoFrom Table 30 (MI 7.6.1), measured after 10 minutes with the boiler at maximum. The ± 0.5 tolerance is for checking an existing appliance. After cleaning or replacing parts, or when adjusting because the reading is outside the tolerance, it is ± 0.2. The technical data (MI 3.2, Table 5) gives the same figures without a tolerance, but says after 30 minutes rather than 10. 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). |
| 11.0% ± 0.5 |
CO₂ at low rate More infoHide infoFrom Table 30 (MI 7.6.1), with the control set to minimum. Same tolerance rules as at high rate. The technical data (MI 3.2, Table 5) gives the same figures without a tolerance, after 30 minutes. |
| 10.5% ± 0.5 |
Maximum CO More infoHide infoThe manual gives two limits. The combustion check flow chart (MI 6.6, Fig. 45) says CO < 350ppm at maximum and minimum rate. Table 30 and the air/gas ratio steps (MI 7.6.1) say less than 200 ppm. The MI doesn’t say which takes priority. |
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CO/CO₂ ratio More infoHide infoThe manual gives two limits. The combustion check flow chart (MI 6.6, Fig. 45) says CO/CO₂ ratio < 0.004 at maximum and minimum rate. Table 30 (MI 7.6.1) gives 0.002 in brackets after the CO limit: CO - less than 200 ppm (0.002 ratio). |
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O₂ | Not given in MI | Not given in MI |
Working inlet pressure More infoHide infoFrom Figs. 43 and 44 (MI 6.5.1), boiler running at maximum. 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 3.2, Table 5). Measure at the gas meter after 10 minutes at maximum (MI 6.5.2). Where there’s no gas meter (e.g. LPG), check CO/CO₂ against Table 30 instead (MI 7.6). |
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Flue integrity More infoHide infoAt the air intake test point on the flue turret, boiler case on, boiler running at maximum, 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 6 720 813 283 (2015/07)
Enter service mode for high and low rate
High rate
- Remove the three screws and the control cover. Take out the plastic tool clipped inside the cover.
- Insert the tool into the mode switch and turn it to MAX.
- Make sure there’s a demand from the external controls. The blue power light flashes (5 pulses at maximum).
Low rate
- Turn the mode switch to MIN. The blue power light flashes 2 pulses.
- Turn it back to MAX to return to maximum.
Ending the test
- Turn the mode switch back to NORM. MI 6.5.2 says press the service button instead, but no such button is shown in the MI.
- It also goes back to normal by itself after 15 minutes if the switch isn’t changed.
Models and GC numbers
| Model | GC number | Gas |
|---|---|---|
| 12Ri ErP | 41-406-41 | NG |
| 15Ri ErP | 41-406-43 | NG |
| 18Ri ErP | 41-406-45 | NG |
| 24Ri ErP | 41-406-47 | NG |
| 12Ri ErP LPG | 41-406-42 | LPG |
| 15Ri ErP LPG | 41-406-44 | LPG |
| 18Ri ErP LPG | 41-406-46 | LPG |
| 24Ri ErP LPG | 41-406-48 | LPG |
Source: Greenstar Ri ErP wall hung RSF gas fired condensing boiler installation, commissioning and servicing instructions, 6 720 813 283 (2015/07).
Sections: Cover (GC numbers); 3.2 Technical data; 6.5 Commissioning; 6.5.1 Checking the gas inlet pressure; 6.5.2 Checking the gas rate; 6.6 CO and combustion checks; 7.3 Checking flue integrity; 7.4 Setting the boiler to maximum; 7.5 Flue gas analysis; 7.6 Setting the air/gas ratio.
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.