Worcester Bosch Greenstar i junior combi (24i junior, 28i junior)
Combi, natural gas and LPG
Combustion figures
| Figure | Natural gas (G20) | LPG (G31) |
|---|---|---|
CO₂ at high rate More infoHide infoFrom the CO₂ settings table in Setting the gas/air ratio (MI page 52), boiler at maximum in service mode. CO₂ should be measured after 10 minutes. The technical data (MI page 5) gives the same figures without a tolerance, for both sizes. The MI says combustion is factory set and no adjustment is needed if the gas inlet pressure is correct. | 9.8% ±0.2 | 11.0% ±0.2 |
CO₂ at low rate More infoHide infoFrom the CO₂ settings table (MI page 52), central heating control set to minimum while in service mode. The technical data gives the same figures without a tolerance, for both sizes. | 9.2% ±0.2 | 10.5% ±0.2 |
Maximum CO More infoHide infoFrom Setting the gas/air ratio (MI page 52), checked at maximum. | less than 200ppm | less than 200ppm |
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 inlet pressure test point on the gas valve with the boiler running at maximum in service mode, with all other gas appliances working (MI Commissioning, page 33). Setting the gas/air ratio (MI page 52) gives the same minimums. The MI gives no appliance inlet or meter figure. |
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Gas rate at maximum More infoHide infoMax. 10 minutes from lighting, natural gas figures for G20 (MI Technical data, page 5). Measure at the gas meter after 10 minutes at maximum (MI Commissioning, page 33). In service mode the boiler runs both the central heating and hot water circuits. The technical data gives a central heating max. rated heat input of 24.62 kW for both sizes, and a hot water max. rated heat input of 24.49 kW (24i junior) and 28.57 kW (28i junior). |
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From 8 716 107 336b (11/05)
Enter service mode for high and low rate
High rate
- Hold the service button for 10 seconds until it lights up. The blue power light flashes quickly.
- Turn the central heating control to maximum. Boiler goes to maximum. Blue light gives 5 pulses.
Low rate
- Turn the central heating control to minimum. Blue light gives 2 pulses.
- Turn the central heating control back to maximum to return to maximum.
Ending the test
- Hold the service button for 2 seconds. Its light goes out and the blue light stays on. (MI p. 33 and 37 just say press it again.)
- It ends by itself after 15 minutes.
Models and GC numbers
| Model | GC number | Gas |
|---|---|---|
| Greenstar 24i junior | 47-311-86 | NG |
| Greenstar 28i junior | 47-311-87 | NG |
| Greenstar 24i junior LPG | 47-311-90 | LPG |
| Greenstar 28i junior LPG | 47-311-91 | LPG |
Source: Greenstar 24i junior/28i junior wall hung RSF gas-fired condensing combination boiler installation, commissioning and servicing instructions, 8 716 107 336b (11/05).
Sections: Cover (GC numbers); Technical data (page 5); Commissioning (page 33); Setting the gas/air ratio, 33. Setting the CO₂ (page 52).
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.