Worcester Bosch Greenstar CDi Classic ErP regular (30CDi, 40CDi)
Regular boiler, natural gas and LPG
Combustion figures
| Figure | Natural gas (G20) | LPG (G31) |
|---|---|---|
CO₂ at high rate More infoHide infoFrom the CO₂ setting table in MI 6.2 (it has no table number), measured 10 minutes after firing, boiler at maximum in performance test mode. The ±0.4% tolerance is for checking an existing appliance. After cleaning or replacing parts, or when adjusting because the reading is outside ±0.4%, the tolerance is ±0.2%. The technical data (MI 2.2, Table 3) gives the same figures without a tolerance. The MI says combustion is factory set and no adjustment is needed if the gas inlet pressure is correct (MI 5.6.1), and the air/gas ratio valve must not be adjusted during commissioning unless the Worcester help line recommends it (MI 5.7). |
| 11.5% ±0.4 |
CO₂ at low rate More infoHide infoFrom the CO₂ setting table in MI 6.2, with the central heating control turned to minimum while in performance test mode. Same tolerance rules as at high rate. The technical data (MI 2.2, Table 3) gives the same figures without a tolerance. |
| 10.5% ±0.4 |
Maximum CO More infoHide infoThe manual gives two limits. The combustion check flow chart (MI 5.7, Fig. 50) says CO < 350ppm at maximum and minimum rate. The setting table and the air/gas ratio steps (MI 6.2) 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 5.7, Fig. 50) says CO/CO₂ ratio < 0.004 at maximum and minimum rate. The setting table (MI 6.2) 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. 48 and 49 (MI 5.6.1), boiler running at maximum in performance test mode, with all other gas appliances working. 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). MI 6.2 repeats the 2.5 and 4 mbar limits. |
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Gas rate at maximum More infoHide infoMax. 10 minutes from lighting, NG figures for G20 (MI 2.2, Table 3). Measure at the gas meter after 10 minutes at maximum (MI 5.6.2). Where there’s no gas meter (e.g. LPG), check CO/CO₂ against the setting table instead (MI 6.2). Table 3 gives a max. rated heat input of 30.9 kW (30CDi) and 42.0 kW (40CDi). |
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Flue integrity More infoHide infoAt the air inlet sample point on the flue turret, boiler case on, boiler running at maximum, readings allowed to stabilise (MI 6.1.2). Readings outside these limits mean a problem with the flue system or combustion circuit, e.g. missing or dislodged seals. The combustion check flow chart (MI 5.7, Fig. 50) gives the same limits. | O₂ ≥ 20.6% CO₂ < 0.2% | O₂ ≥ 20.6% CO₂ < 0.2% |
From 6 720 815 723 (2015/05)
Enter service mode for high and low rate
High rate
- Hold the performance test button for 10 seconds until it stays lit. The blue power light pulses five times.
- Turn the central heating temperature control to maximum. The boiler goes to maximum.
- If the display alternates -II- and the flow temperature, it’s on its 15-minute minimum run to fill the condensate trap after power was off.
Low rate
- Turn the central heating temperature control to minimum. The boiler goes to minimum.
- Turn it back to maximum to return to maximum.
Ending the test
- Hold the performance test button for 2 seconds until it goes out. The blue power light then stays on.
- It ends by itself after 15 minutes.
Models and GC numbers
| Model | GC number | Gas |
|---|---|---|
| 30CDi Classic Regular ErP | 41-406-33 | NG |
| 40CDi Classic Regular ErP | 41-406-35 | NG |
| 30CDi Classic Regular ErP LPG | 41-406-34 | LPG |
| 40CDi Classic Regular ErP LPG | 41-406-36 | LPG |
Source: Greenstar CDi Classic Regular ErP wall hung RSF gas fired condensing regular boiler installation, commissioning and servicing instructions, 6 720 815 723 (2015/05).
Sections: Cover (GC numbers); 2.2 Technical data; 5.6 Commissioning; 5.6.1 Checking the gas inlet pressure; 5.6.2 Checking the gas rate; 5.7 CO and combustion checks; 6.1.2 Checking flue integrity; 6.1.4, Set the boiler to maximum paragraph; 6.2 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.