Worcester Bosch Worcester 2000 combi (GC2000iW 25 C, 30 C)
Combi, natural gas
Combustion figures
| Figure | Natural gas (G20) |
|---|---|
CO₂ at high rate More infoHide infoFrom Table 29 (MI 9.6), measured 10 minutes after firing, boiler at maximum in chimney sweep mode. All CO/CO₂ readings are taken with the combustion chamber cover on (MI 9.9). The technical data (MI 13.1) gives 9.6% at maximum rated heat output after 10 minutes, for both sizes. | Between 9.0 and 10.8% |
CO₂ at low rate More infoHide infoFrom Table 29 (MI 9.6), measured 10 minutes after firing, boiler at minimum in chimney sweep mode and allowed to stabilise. The technical data (MI 13.1) gives 8.6% at minimum rated heat output after 10 minutes, for both sizes. | A minimum of 0.6 lower than the maximum reading taken but above 8.2% |
Maximum CO More infoHide infoThe manual gives two different figures. The commissioning flow chart (MI 6.9, Fig. 56) says CO < 350ppm at maximum and minimum rate. The combustion settings table (MI 9.6, Table 29) says <250ppm at maximum and minimum rated output, 10 minutes after firing. The manual doesn’t say which takes priority. |
|
CO/CO₂ ratio More infoHide infoFrom the commissioning flow chart (MI 6.9, Fig. 56), at maximum and minimum rate. MI 6.7 says the technical data gives the CO/CO₂ ratios, but the technical data table (MI 13.1) doesn’t list one. | < 0.004 |
O₂ at high rate More infoHide infoFrom Table 29 (MI 9.6), measured 10 minutes after firing. No tolerance given. | 4.0 % |
O₂ at low rate More infoHide infoFrom Table 29 (MI 9.6), measured 10 minutes after firing. No tolerance given. | 5.5 % |
Working inlet pressure More infoHide infoAt the appliance inlet, with the boiler at maximum in chimney sweep mode (MI 6.6). At the gas valve inlet test point: 16.5–20.5 mbar. At the meter: 19–23 mbar. Allowed drop: 1 mbar across the pipework, 1.5 mbar across the appliance (Table 20). Nominal inlet pressure 20.0 mbar (MI 13.1). | 18–22 mbar |
Gas rate at maximum More infoHide infoMaximum rate, 10 minutes from lighting (MI 13.1, where the sizes are listed as 25kW and 30kW). Measure at the meter after at least 10 minutes at maximum in chimney sweep mode, with all other gas appliances off (MI 6.7). The MI says the gas rate assumes an NG calorific value of 34-9 MJ/m³ net (printed that way). |
|
Flue integrity More infoHide infoAt the air inlet sample point on the flue turret/adaptor, combustion casing on, boiler at maximum in chimney sweep mode (MI 6.10). MI 6.10 lists both as checks, but the flow chart (MI 6.9, Fig. 56) shows O₂ ≥ 20.6% OR CO₂ < 0.2%. Readings outside these limits indicate a problem with the flue system or combustion circuit. | O₂ ≥ 20.6% CO₂ < 0.2% |
From 6 721 814 551 (2019/09)
Enter service mode for high and low rate
High rate
- Hold ok for at least 5 seconds until the chimney sweep symbol shows.
- It goes to maximum by itself. Display shows 100% and the flow temperature in turn.
Low rate
- Press ▼ for minimum. Display shows the minimum % and the flow temperature in turn.
Ending the test
- Press ok to come out. It also ends by itself after 30 minutes.
Models and GC numbers
| Model | GC number | Gas |
|---|---|---|
| GC2000iW 25 C NG | 47-800-25 | NG |
| GC2000iW 30 C NG | 47-800-24 | NG |
Source: Worcester 2000 (GC2000iW C) installation and maintenance instructions, 6 721 814 551 (2019/09).
Sections: 3.4 Appliance type overview; 6.5 Chimney sweep mode; 6.6 Checking gas inlet pressure; 6.7 Checking the gas rate; 6.9 CO and combustion check; 6.10 Checking flue integrity; 9.6 Flue gas analysis; 9.9 Setting the air/gas ratio; 13.1 Technical data.
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.