Worcester Bosch Greenstar Highflow 440 combi (440)
Floor standing combi, natural gas and LPG
Combustion figures
| Figure | Natural gas (G20) | LPG (G31) |
|---|---|---|
CO₂ at high rate More infoHide infoFrom the CO₂ table in Setting the gas/air ratio (Replacement of parts, MI page 38), CO₂ reading at max. rated heat output, at the flue gas testing point. No tolerance given. The table labels the gases Natural gas type H (G20) and LPG (propane) (G31). The technical data (MI page 4) gives the same figures. The MI says the appliance is set at the factory and the CO₂ settings only need adjusting after stripping down, replacing the fan, burner or gas valve, or converting to a different gas (MI pages 33 and 37). | 9.2% | 10.8% |
CO₂ at low rate More infoHide infoFrom the CO₂ table on MI page 38, CO₂ reading at min. rated heat output. No tolerance given. The scan of this table is faint, but it reads 8.8% and the technical data (MI page 4) clearly gives 8.8% (NG) and 10.5% (LPG). | 8.8% | 10.5% |
Maximum CO More infoHide infoSetting the gas/air ratio (MI page 38) says that if the CO level is over 300ppm the gas volumetric flow rate is too high, and to reduce the gas flow rate on the adjustable gas flow restrictor (F) until the CO level is below 100ppm. It says this after both the max. and min. rate CO₂ checks. The MI gives no other CO limit. |
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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 infoFrom Starting the appliance, Checking gas inlet pressure (MI page 27): gauge connected to the gas valve inlet test point (F), with button (E) pressed until it lights. The MI says the inlet pressure must be between N.G. 18 - 24 mbar, and gives L.P.G. 37 mbar. The technical data (MI page 4) gives a gas supply pressure of 20 (NG G20) and 37 (LPG G31), but prints the units as m³/h and kg/h. |
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Gas rate at maximum More infoHide infoMax. 10 minutes from lighting (MI page 4), for NG G20 at CVnet 34.02 MJ/m³ and LPG at CVnet 88 MJ/m³ (as printed). The technical data gives a max. rated heat input of 29.5 kW for both central heating and hot water. The MI gives no steps for checking the gas rate. | 3.1 m³/h | 2.3 kg/h |
From 6-720-611-730a (08.04)
Enter service mode for high and low rate
High rate
- Hold the service button (spanner symbol) until the display shows – – and the button lights.
- Turn the CH temperature control until the display shows 2.0. After a short delay it shows the current mode (0. = normal).
- Turn the DHW temperature control until the display shows 2. for maximum. The display and service button flash.
Low rate
- Turn the DHW temperature control anticlockwise until the display shows 1. for minimum. The display and service button flash.
Ending the test
- Turn the DHW control anticlockwise to the stop so the display shows 0., then hold the service button until it shows [ ].
- Set both temperature controls back to where they were. The display goes back to the CH flow temperature.
Models and GC numbers
| Model | GC number | Gas |
|---|---|---|
| Highflow 440 | 47-311-82 | NG |
| Highflow 440 LPG | 47-311-83 | LPG |
Source: Worcester Bosch Greenstar Highflow 440 floor standing RSF gas-fired combination boiler installation, commissioning and servicing instructions, 6-720-611-730a (08.04).
Sections: Cover (GC numbers); Technical data (page 4); Starting the appliance, Checking gas inlet pressure (page 27); Inspection and service, Setting gas/air ratio (page 33); Replacement of parts, Setting the gas/air ratio (pages 37–38).
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.