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Alpha Checked against MI

Alpha E-Tec R regular (25R)

Regular boiler, natural gas (LPG by conversion kit)

Combustion figures

FigureNatural gas (G20)LPG (G31)
CO₂ at high rate
More infoHide infoFactory set figures. Check with the case fitted (MI 6.12). Chimney sweep mode at 99% checks the maximum heating (CH) figure (MI 6.6); the MI gives no tolerance for it. The DHW figure applies with the Alpha Diverter Kit or DHW relay fitted.
Max CH output
9.7%
Max DHW output
9.7% (+0.5/−0.2%)
Max CH output
11.4%
Max DHW output
11.4% (+0.1/−0.3)
CO₂ at low rate
More infoHide infoChimney sweep mode at 0% (minimum output), case fitted (MI 6.6, 6.12).
8.8% (+0.2/−0.3%)10.6% (+0.3/−0.1)
Maximum CO
More infoHide infoLPG: MI 3.2 says other technical data is the same as NG.
450 ppm450 ppm
CO/CO₂ ratio
More infoHide infoMaximum ratio (MI 3.1). Section 7 says if the ratio is greater than 0.004, check and service until it is less than 0.004. LPG: MI 3.2 says other technical data is the same as NG.
0.0040.004
O₂
Not given in MINot given in MI
Working inlet pressure
More infoHide infoGiven as gas supply pressure, a single figure with no range (MI 3.1, 3.2). Measurement point not stated in MI. The inlet pressure test point is on the gas valve (Fig. 6.2).
20 mbar37 mbar
Gas rate at maximum
More infoHide infoAt maximum output (MI 3.1, 3.2).
3.05 m³/h2.24 kg/h (0.62 g/s)

From Part No. 1.041526 rev. ST.003864/000 (1118/D389)

Enter service mode for high and low rate

High rate

  1. With no heating or hot water demand, hold RESET for 8 seconds. The parasol and snowman symbols flash together.
  2. A Climatic controller, if fitted, shows ERR>07. That’s not a fault.
  3. Turn the CH control knob to maximum for full output (99%).

Low rate

  1. Turn the CH control knob to minimum for minimum output (0%).
Ending the test
  • Turn the boiler off (hold the On-Off/Standby button for 8 seconds) to come out. It also ends by itself after 15 minutes.

Models

ModelGas
E-Tec 25RNG

Source: Alpha E-Tec 25R Installation and Servicing Instructions, Part No. 1.041526 rev. ST.003864/000 (1118/D389).

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.

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.