30
Alpha E-Tec 25R - Commissioning
6.11
CONVERTING THE BOILER TO OPERATE ON LPG
If the boiler has to be converted for LPG, obtain the relative conversion kit. The gas conversion operation
must be carried out by a competent and suitably qualified Gas Safe registered engineer.
To convert to LPG the following operations are required:
•
Isolate the appliance from the electric and gas supplies.
•
Replace the injector located on the upper fitting of the gas valve and re-seal the connections (Fig. 7.4).
•
Re-instate gas and electric supplies.
•
Calibrate the new fan speed for LPG (Section 6.13).
•
Check / adjust the correct CO
2
(Section 6.12).
•
After completing the conversion, apply the sticker (supplied in the conversion kit) near the boiler data plate.
Using an indelible marker pen, delete the data relative to the old type of gas.
These adjustments must be made according to the type of gas used, given in the table (Section 3).
6.12 CO
2
SET UP PROCEDURE
The air gas ratio of the boiler has been factory set and should not require adjusting during first
commission. If adjustment is recommended or required the engineer must be competent to carry out this
work.
Before starting this procedure please check the following:
The front case is fitted.
The flue system is not blocked or restricted and is to the correct specification.
The gas supply working pressure is correct and the system has been purged.
There is no recirculation in the boiler flue circuit.
The condensate trap is pre-filled.
If the flow temperatures are getting up to maximum operating temperature during the procedure it is possible to open a hot
tap and turn the controls to heating and hot water demand to lose the heat.
Attention:
the CO
2
checks must be carried out with the case fitted, while the gas valve adjustments must be carried out with
the front case removed.
Calibration of the minimum CO
2
(minimum output)
Refer to Section 6.6 and enter the chimney sweep mode use the CH control knob to set the output to minimum (0%). Insert
the analyser probe into the flue test point (Fig. 6.3) and check that the CO
2
value is as specified in Section 3.1, otherwise
adjust the screw (Fig. 6.2) To increase the CO
2
value, turn the adjustment screw in a clockwise direction and vice versa to
decrease.
Calibration of the maximum CO
2
(maximum output)
When you finish the minimum CO
2
adjustment, while maintaining the chimney sweep function active, use the CH control
knob to set the output to maximum (99%). Insert the analyser probe into the flue test point (Fig. 6.3) and check that the CO
2
value is as specified in Section 3.1, otherwise adjust the screw (Fig. 6.2). To increase the CO
2
value, turn the adjustment
screw (Fig. 6.2) in a clockwise direction and vice versa to decrease it.
Re-check the minimum setting and repeat the procedure if required.
At every gas valve adjustment, it is necessary to wait for the boiler to stabilise itself at the value set (approx. 30 sec.).
Fig. 6.2
Fig. 6.3
Outlet pressure
test point
Inlet pressure
test point
Wiring plug
+
+
Off/Set adjustment
screw (Min. CO )
2
Gas outlet flow
adjustment screw
(Max. CO )
2
Flue test point
F (+)
Air test point
A (-)
