Worcester Bosch Checked against MI

Worcester Bosch Greenstar CDi combi (25CDi, 30CDi, 35CDi, 40CDi)

Combi, natural gas and LPG

Combustion figures

Figure	Natural gas (G20)	LPG (G31)
CO₂ at high rate More infoHide info From the CO₂ setting table in Setting the gas/air ratio (MI page 53), boiler at maximum in central heating boost mode. CO₂ should be measured 10 minutes after firing. The technical data (MI page 6) 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.	25CDi, 30CDi, 35CDi 9.6 % ±0.2 40CDi 9.7 % ±0.2	11.5 % ±0.2
CO₂ at low rate More infoHide info From the CO₂ setting table (MI page 53), central heating control set to minimum while in central heating boost mode. The technical data gives the same figures without a tolerance.	25CDi, 30CDi, 35CDi 9.0 % ±0.2 40CDi 9.1 % ±0.2	10.5 % ±0.2
Maximum CO More infoHide info From Setting the gas/air ratio (MI page 53), checked at maximum.	less than 200 ppm	less than 200 ppm
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 info Measured at the gas valve inlet test point with the boiler running at maximum in central heating boost mode, with all other gas appliances working (MI Commissioning, page 36). Setting the gas/air ratio (MI page 53) gives both as minimums: a minimum of 18 mbar for natural gas and 37 mbar for LPG. The MI gives no appliance inlet or meter figure.	Gas valve test point minimum 18 mbar	Gas valve test point 37 mbar
Gas rate at maximum More infoHide info Max. 10 minutes from lighting, natural gas figures for G20 (MI Technical data, page 6). Measure at the gas meter after 10 minutes at maximum (MI Commissioning, page 36). In central heating boost mode the boiler runs both the central heating and hot water circuits. The technical data gives a central heating max. rated heat input of 25.8 kW (25CDi) and 30.9 kW (30CDi, 35CDi, 40CDi), and a hot water max. rated heat input of 25.8, 30.9, 35.0 and 40.0 kW on natural gas. For the 40CDi on LPG it gives 42.0 kW hot water input.	25CDi 2.6 m³/h 30CDi 3.2 m³/h 35CDi 3.7 m³/h 40CDi 4.2 m³/h	25CDi 2.0 kg/h 30CDi 2.4 kg/h 35CDi 2.7 kg/h 40CDi 3.1 kg/h

From 6 720 612 485b (2006/01)

Enter service mode for high and low rate

High rate

Hold the central heating boost button for 10 seconds until it lights up and stays lit.
Turn the central heating temperature control fully to max. The boiler goes to maximum.

Low rate

Turn the central heating temperature control to minimum. The boiler goes to minimum.
Turn it back to max to return to maximum.

Ending the test

Hold the central heating boost button for 2 seconds. It goes out and the blue power light stays on.
It also ends by itself after 15 minutes.

Models and GC numbers

Model	GC number	Gas
Greenstar 25CDi	47-311-92	NG
Greenstar 30CDi	47-311-93	NG
Greenstar 35CDi	47-311-94	NG
Greenstar 40CDi	47-311-95	NG
Greenstar 25CDi LPG	47-311-96	LPG
Greenstar 30CDi LPG	47-311-97	LPG
Greenstar 35CDi LPG	47-311-98	LPG
Greenstar 40CDi LPG	47-406-01	LPG

Source: Worcester Bosch Greenstar 25CDi/30CDi/35CDi/40CDi wall hung RSF gas-fired condensing combination boiler installation, commissioning and servicing instructions, 6 720 612 485b (2006/01).

Sections: Cover (GC numbers); Technical data (page 6); Commissioning (page 36); Setting the gas/air ratio, 5. Setting the CO₂ (page 53).

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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.