Alpha Checked against MI

Alpha E-Tec combi (E-Tec 28, 33)

Combi, natural gas and LPG

Combustion figures

Figure	Natural gas (G20)	LPG (G31)
CO₂ at high rate More infoHide info MI figures for CO₂ at maximum DHW output, which is the 99% (Max DHW output) level in chimney sweep mode. The MI also gives CO₂ at maximum CH output with no tolerance (NG: E-Tec 28 9.7%, E-Tec 33 9.5%; LPG: E-Tec 28 11.4%, E-Tec 33 11.2%), but says CO₂ testing at the Max CH output level is not required. Check with the case fitted and wait about 30 seconds for the boiler to stabilise.	E-Tec 28 9.7% (+0.5/−0.2%) E-Tec 33 9.5% (±0.2%)	E-Tec 28 11.4% (+0.1/−0.3) E-Tec 33 11.2% (+0.2/−0.4)
CO₂ at low rate More infoHide info CO₂ at minimum output, the 0% (low fire) level in chimney sweep mode. Check with the case fitted.	E-Tec 28 8.8% (+0.2/−0.3%) E-Tec 33 8.6% (+0.2/−0.3%)	E-Tec 28 10.6% (+0.3/−0.1) E-Tec 33 10.0% (+0.4/−0.2)
Maximum CO More infoHide info The LPG table does not list CO; the MI says other technical data for LPG is the same as NG data.	450 ppm	450 ppm
CO/CO₂ ratio More infoHide info The LPG table does not list the ratio; the MI says other technical data for LPG is the same as NG data. The servicing section asks for further checks if the ratio is greater than 0.004.	0.004	0.004
O₂	Not given in MI	Not given in MI
Working inlet pressure More infoHide info Given as the gas supply pressure in the technical data tables. Measurement point not stated in MI.	20 mbar	37 mbar
Gas rate at maximum More infoHide info Gas rate at maximum output.	E-Tec 28 3.05 m³/h E-Tec 33 3.45 m³/h	E-Tec 28 2.24 kg/h (0.62 g/s) E-Tec 33 2.53 kg/h (0.7 g/s)

From Part No. 1.042188 rev. ST.003781.001, 1018/D385

Enter service mode for high and low rate

High rate

With no heating or hot water demand, hold RESET for 8 seconds. The parasol and snowman symbols flash together.
If a Climatic controller is fitted it shows ERR>07. That’s not a fault.
Press DHW up ▲ (tap symbol) until it’s at 99%, maximum. The levels are 0%, 80–90% and 99%.

Low rate

Press DHW down ▼ (tap symbol) to set 0%, minimum.
Press DHW up ▲ to go back to maximum.

Ending the test

Hold Off/Stand-by/Summer/Winter for 8 seconds to turn the boiler off and come out. It also ends by itself after 15 minutes.

Models and GC numbers

Model	GC number	Gas
E-Tec 28 (NG)	47-532-69	NG
E-Tec 33 (NG)	47-532-70	NG
E-Tec 28 (LPG)	47-532-73	LPG
E-Tec 33 (LPG)	37-532-74	LPG

Source: Alpha E-Tec 28 and 33 Installation and Servicing Instructions, Part No. 1.042188 rev. ST.003781.001, 1018/D385.

Sections: 3.1 Technical performance data - natural gas; 3.2 Technical performance data - LPG; 6.6 Checking the combustion - chimney sweep mode; 6.11 Converting the boiler to operate on LPG; 6.12 CO2 set up procedure; 7 Routine servicing (combustion check).

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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.