Alpha InTec2 20SE Installation And Servicing Instruction page 28

Frost Thermostat
The boiler incorporates a built in frost thermostat which automatically turns on the boiler if the water in the boiler falls below
4°C, providing the electrical supply is on and the boiler is in standby mode. The boiler will operate until the water temperature
in the boiler reaches 42°C.
Any other pipework outside of the boiler must be protected from the risk of freezing and insulated. Additional protection from
an external frost thermostat and pipe thermostats should be considered.
Pump Cycle
If the electrical supply is on and the boiler has not operated for 24 hours in heating or hot water, the pump will operate
automatically for thirty seconds every 24 hours.
5.7 CHECKING THE COMBUSTION - CHIMNEY SWEEP MODE
As part of the Benchmark Checklist procedure the combustion levels of the boiler when the installation is completed must be
measured and recorded.
The air gas ratio of the boiler has been factory-set and should not require adjusting during commissioning. If adjustment is
recommended or required the engineer must be competent to carry out this work.
If the boiler requires adjusting or setting to operate on LPG, further guidance on the full calibration setup procedure is
detailed in Section 5.12.
Standard Combustion Check Procedure - This check must be carried out with the front case fitted.
Without any CH or DHW demand, press and hold the reset button for eight seconds and the boiler will fire at a fixed output
depending on the position of the central heating thermostat knob. The parasol and snowman (
time to indicate this mode, if a Climatic controller is fitted it will display ERR>07 code on the controller (this is not a fault).
The boiler output can then be manually controlled by turning the Central Heating control knob from the minimum CH output
to the maximum CH output. The display will display the percentage of the CH heat output (values from 00 minimum, to 99
maximum). This mode will remain active for fifteen minutes or can be cancelled by turning the boiler off.
Set the CH knob to minimum to check the minimum CO
indicated by the ( ) symbol flashing. When the symbol stops flashing, check the combustion and record the reading.
Set the CH knob to maximum to check the maximum heating CO
and record the reading.
Set the CH knob until the display shows 78 (for 20SE) or 49 (for 30SE) and check the CO
Again allow the burner to stabilise as described above and check the reading.
If the flow temperatures are getting up to maximum operating temperature during the procedure it is possible to open a hot
tap to lose some heat, with the control in heating and hot water request.
Note: With the tap open the boiler still remains at the output set by the CH knob position, i.e. between minimum and
maximum CH output.
If the CO readings are not within the stated tolerance (refer to Section 2.1) then check the installation including the complete
2
flue assembly and repeat the above process.
Note: In this mode only the boiler flow sensor controls the maximum temperature.
5.8 FINAL COMMISSIONING
1. Allow the heating system to heat up, then balance the system to achieve the necessary temperature difference across
the heating flow and return pipes at the boiler and check the system volume and pressure. (Refer to Section 2.1).
2. Turn off the boiler.
3. Thoroughly flush out the water pipework (refer to Section 3.9).
4. Refill and re-pressurise the system as described in Section 5.1.
5. Add the correct level of inhibitor to the system as detailed in the instructions supplied with the inhibitor.
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Alpha InTec² 20SE and 30SE - Commissioning
2
Outlet pressure
test point
Coil
Wiring plug
Inlet pressure
test point
Fig. 5.2
reading, wait for the boiler to carry out a self-diagnosis test,
, again allow the burner to stabilise as described above
2
Flue test point
F (+)
) will flash at the same
at the medium level (ignition).
2
Air test point
A (-)
Fig. 5.3