Vaillant ecoTEC plus (VU 446/5-5, VU 606/5-5)
Wall-hung boiler with internal pump, natural gas and LPG
Combustion figures
| Figure | Natural gas (G20) | LPG (G31) |
|---|---|---|
CO₂ at high rate More infoHide infoAfter 5 minutes in full load mode (check programme P.01), front casing closed, at the flue gas analysis point. The figures shown are for checking during start-up; for checking after resetting the MI gives the same figures with a tolerance of ± 0.3 vol. %. With the front casing removed (the value used when adjusting, MI 7.10.5): NG 9.0 ± 1.0 vol. %; LPG VU 446/5-5 9.7 ± 1.0 vol. %, VU 606/5-5 9.9 ± 1.0 vol. % (± 0.3 vol. % after resetting). | 9.2 ± 1.0 vol. % |
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CO₂ at low rate | Not given in MI | Not given in MI |
Maximum CO More infoHide infoFrom the Benchmark flowchart in the MI (Appendix G), which doesn’t split by gas type. The MI contradicts itself: the checks at maximum and minimum rate say less than 350 ppm, but the re-check at maximum rate after checking the seals around the burner, flue, door and case says less than 335 ppm. The MI doesn’t explain the difference. |
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CO/CO₂ ratio More infoHide infoAt maximum and minimum rate (Benchmark flowchart, MI Appendix G). | Less than 0.004 | Less than 0.004 |
O₂ at high rate More infoHide infoAfter 5 minutes in full load mode, front casing closed. The figures shown are for checking during start-up; for checking after resetting the MI gives the same figures with a tolerance of ± 0.5 vol. %. | 4.5 ± 1.8 vol. % |
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O₂ at low rate | Not given in MI | Not given in MI |
Working inlet pressure More infoHide infoWith the boiler at full load on check programme P.01. Appliance inlet is the test nipple at the gas connection (point D in MI 7.10.4), the same for both sizes. The gas valve test point figure (point B) differs by size: NG VU 446/5-5 16.00–24.00 mbar, VU 606/5-5 15.50–23.50 mbar; LPG VU 446/5-5 24.50–44.50 mbar, VU 606/5-5 23.50–43.50 mbar. The technical data (MI Appendix K) gives a gas supply pressure of 20.0 mbar for G20 and 37.0 mbar for G31. |
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Gas rate at maximum More infoHide infoNominal gas flow rate at maximum heat input (Qnw 45.2 kW for VU 446/5-5, 60.0 kW for VU 606/5-5), measured at the gas meter with the front casing fitted, after at least 5 minutes on check programme P.01. Permitted range (+5% / −10%): NG VU 446/5-5 4.30–5.02 m³/h, VU 606/5-5 5.71–6.66 m³/h; LPG VU 446/5-5 1.67–1.94 m³/h, VU 606/5-5 2.21–2.58 m³/h. The MI calls these H gas and P gas. |
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Flue integrity More infoHide infoAt the air inlet test point, boiler at maximum rate (Benchmark flowchart, MI Appendix G). MI 7.10.2 says to check for flue gas recirculation at the air analysis point on extended flue installations. | O₂ ≥ 20.6% CO₂ < 0.2% | O₂ ≥ 20.6% CO₂ < 0.2% |
From 0020261389_02 (13.11.2018)
Enter service mode for high and low rate
High rate
Low rate
Models and GC numbers
| Model | GC number | Gas |
|---|---|---|
| VU 446/5-5 (H-GB) ecoTEC plus | 41-694-28 | NG |
| VU 606/5-5 (H-GB) ecoTEC plus | 41-694-29 | NG |
Source: Installation and maintenance instructions ecoTEC plus VU 446/5-5 (H-GB), VU 606/5-5 (H-GB), 0020261389_02 (13.11.2018).
Sections: 2.3 Validity of the instructions; 7.9 Using check programmes; 7.10.2 Checking the leak-tightness of the flue gas installation and flue gas recirculation; 7.10.3 Checking the gas flow rate; 7.10.4 Checking the gas flow pressure; 7.10.5 Checking the CO₂ content and, if necessary, adjusting it (air ratio setting); Appendix G Commissioning Checklist (Benchmark flowchart); Appendix J Gas adjustment values; Appendix K Technical data.
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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.