Worcester Bosch Greenstar Ri 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 the CO/CO₂ settings for Greenstar Ri tables in Setting the air/gas ratio (MI page 39 for the SIT 848.093 Sigma valve, page 40 for the Dungs GB-ND 055 D01 S20 valve) and Gas conversion (MI page 47); the three tables are the same. Mode switch set to maximum. The tables say CO/CO₂ should be measured after 10 minutes (the Gas conversion table says CO₂). Flue gas test point on the appliance flue elbow, under cap E. The setting procedure starts with the outer case removed (MI page 38) and the case is refitted at the end (MI pages 39, 40). The technical data (MI page 4) gives the same figures without a tolerance, for all sizes, but says after 30 mins. The MI says the combustion is factory set and no adjustment is required if the gas inlet pressure is correct (MI page 30). | 9.8% ± 0.5% | 11.0% ± 0.5% |
CO₂ at low rate More infoHide infoFrom the same CO/CO₂ settings tables (MI pages 39, 40 and 47), mode switch set to minimum. The technical data (MI page 4) gives the same figures without a tolerance, for all sizes, but says after 30 mins. | 9.2% ± 0.5% | 10.5% ± 0.5% |
Maximum CO More infoHide infoPrinted under the CO/CO₂ settings tables (MI pages 39, 40 and 47) as CO - less than 200ppm (0.002 ratio). The setting steps say to check CO is less than 200ppm at maximum and again at minimum (MI pages 39, 40). | less than 200ppm | less than 200ppm |
CO/CO₂ ratio More infoHide infoPrinted with the CO limit under the CO/CO₂ settings tables (MI pages 39, 40 and 47): CO - less than 200ppm (0.002 ratio). | 0.002 | 0.002 |
O₂ | Not given in MI | Not given in MI |
Working inlet pressure More infoHide infoMeasured at the gas valve inlet point (inlet test nipple on the SIT and Dungs valves) with the boiler running at maximum, mode switch set to maximum, and with all other gas appliances working (MI Commissioning, page 30). Setting the air/gas ratio says the inlet pressure at the inlet pressure point on the gas valve should be no less than 18.5mb for NG or 37mb for LPG (MI pages 39, 40). The general checks on the back cover ask whether the incoming gas pressure is at least 18mbar with the boiler at maximum output, without saying where it’s measured or for which gas; that’s lower than the 18.5 mbar natural gas minimum above. The MI gives no appliance inlet, meter or regulator figure. |
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Gas rate at maximum More infoHide infoGas flow rate - Max. 10 minutes from lighting, Natural Gas G20 and Propane Gas (LPG) (MI Technical data, page 4). Measure at the gas meter after 10 minutes operation at maximum (MI Commissioning, page 30). The technical data gives a max. rated heat input net of 12.32 kW (12Ri), 15.40 kW (15Ri), 18.48 kW (18Ri) and 24.62 kW (24Ri), the same for both gases. |
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From 8 716 115 168a (06/2008)
Enter service mode for high and low rate
High rate
- Remove the 3 screws and the control cover. The plastic tool for the mode switch is clipped inside the cover.
- Make sure there is a demand from the external controls.
- Use the tool to turn the mode switch to MAX. The blue power indicator flashes (5 pulses).
Low rate
- Turn the mode switch to MIN. The power indicator flashes (2 pulses).
- Turn it back to MAX to return to maximum.
Ending the test
- Turn the mode switch to NORM.
- At MAX it ends by itself after 15 minutes if the switch isn’t moved.
Models and GC numbers
| Model | GC number | Gas |
|---|---|---|
| Greenstar 12Ri | 41-311-63 | NG |
| Greenstar 15Ri | 41-311-75 | NG |
| Greenstar 18Ri | 41-311-77 | NG |
| Greenstar 24Ri | 41-311-65 | NG |
| Greenstar 12Ri LPG | 41-311-64 | LPG |
| Greenstar 15Ri LPG | 41-311-76 | LPG |
| Greenstar 18Ri LPG | 41-311-78 | LPG |
| Greenstar 24Ri LPG | 41-311-66 | LPG |
Source: Worcester Greenstar 12Ri, 15Ri, 18Ri & 24Ri wall hung RSF gas fired condensing boiler for open vented and sealed central heating systems and indirect mains fed domestic hot water installation, commissioning and servicing instructions, 8 716 115 168a (06/2008).
Sections: Cover (GC numbers); Technical data (page 4); Commissioning (page 30); Setting the air/gas ratio (page 38); Setting the air/gas ratio for the SIT 848.093 Sigma, 1. Setting the CO/CO₂ (page 39); Setting the air/gas ratio for the Dungs GB-ND 055 D01 S20, 1. Setting the CO/CO₂ (page 40); Gas conversion (page 47); General checks (back cover).
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.