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Alpha Checked against MI

Alpha Alpha Evoke combi (Evoke 28, 33)

Combi, natural gas and LPG

Combustion figures

FigureNatural gas (G20)LPG (G31)
CO₂ at high rate
More infoHide infoMI figure for CO₂ at maximum DHW output, checked in chimney sweep mode at 99% (max DHW output) with the case fitted. The technical data also gives CO₂ at maximum CH output (NG: Evoke 28 9.7%, Evoke 33 9.5%; LPG: Evoke 28 11.4%, Evoke 33 11.2%, no tolerance given), but MI 6.6 says CO₂ testing at the 80–90% max CH output setting is not required. MI 6.6 refers to Section 2.1 for the tolerance, but Section 2 is safety symbols: the tolerances are in Sections 3.1 and 3.2.
Evoke 28
9.7% (+0.5/−0.2%)
Evoke 33
9.5% (±0.2%)
Evoke 28
11.4% (+0.1/−0.3)
Evoke 33
11.2% (+0.2/−0.4)
CO₂ at low rate
More infoHide infoCO₂ at minimum output, chimney sweep mode at 0% (low fire), case fitted.
Evoke 28
8.8% (+0.2/−0.3%)
Evoke 33
8.6% (+0.2/−0.3%)
Evoke 28
10.6% (+0.3/−0.1)
Evoke 33
10.0% (+0.4/−0.2)
Maximum CO
More infoHide infoRate not stated in MI. LPG: the MI’s LPG table (Section 3.2) says other technical data is the same as NG data.
450 ppm450 ppm
CO/CO₂ ratio
More infoHide infoMaximum CO/CO₂ ratio. If above 0.004, MI Section 7 says check for flue gas recirculation, flue restrictions and gas supply pressure and rate, then clean the burner and check the electrode. LPG: taken from the NG data, as Section 3.2 says other technical data is the same.
0.0040.004
O₂
Not given in MINot given in MI
Working inlet pressure
More infoHide infoGiven as gas supply pressure in the technical data, with no range or tolerance. Measurement point not stated in MI.
20 mbar37 mbar
Gas rate at maximum
More infoHide infoGas rate at maximum output, as given in the technical data.
Evoke 28
3.05 m³/h
Evoke 33
3.45 m³/h
Evoke 28
2.24 kg/h (0.62 g/s)
Evoke 33
2.53 kg/h (0.7 g/s)

From Part No. 1.042372 rev. ST.003782.000 (0918/D386)

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. Press the hot water up button (top left, tap symbol with an up arrow) until it reaches maximum, 99%.
  3. If a Climatic controller is fitted it shows ERR>07. That’s not a fault.

Low rate

  1. Press the hot water down button (bottom left, tap symbol with a down arrow) until it reaches minimum, 0%.
  2. Press the hot water up button to go back to maximum.
Ending the test
  • Turn the boiler off (hold the Off/Stand-by/Summer/Winter button for 8 seconds) to come out. It also ends by itself after 15 minutes.

Models and GC numbers

ModelGC numberGas
Evoke 28 (NG)47-532-71NG
Evoke 28 (LPG)47-532-75LPG
Evoke 33 (NG)47-532-72NG
Evoke 33 (LPG)37-532-76LPG

Source: Alpha Evoke 28 and 33 Installation and Servicing Instructions, Part No. 1.042372 rev. ST.003782.000 (0918/D386).

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.