© MHG Heating Ltd
42
MHG Heating Ltd Unit 4 Epsom Downs Metro Centre, Waterfield, Tadworth, Surrey KT20 5LR
Telephone 01737 358000 Fax 08456 448803 Email
Web www.mhgheating.co.uk
010517
11.0 Commissioning The Appliance
11.1 Pre-Commissioning Checks
Prior to undertaking the commissioning of the unit please ensure that the system water has been cleansed
and treated with a suitable inhibitor as detailed in Filling the system and system water quality.
A tightness test must be carried out from the appliance to the first isolation valve (or further if connected to
untested pipework).
11.2 Combustion System Commissioning
The combustion of the appliance must be commissioned by a suitably qualified engineer using a flue gas
analyser.
The following steps must be followed to ensure the correct and complete commissioning of the combustion
system has taken place.
1: On completion of a tightness test the boiler must first be fired and tested in Maximum output.
2: To operate the boiler in maximum output the MODE selection butting is to be pressed and held for at least
3 seconds. 'Control functio stop' will appear on the display.
3: Press the INFORMATION button once, the screen will now display the modulation rate of the boiler as %.
4: Adjust the setting to 100% using the NAVIGATION button, then press OK to set.
5: Set the CO2 value by turning the throttle screw shown in the image below.
6: Adjustments are to be done in small increments and the combustion allowed to stabalise before re-
adjusting.
7: Once the correct CO2 valve has been set at Maximum output press the OK button, the 100% will flash.
Use the NAVIGATION button to alter the value to read 0%. Press the OK button to set the boiler into
Minimum output.
8: Set the CO2 value by adjusting the zero point screw shown below.
9: Adjustments are to be done in small increments and the combustion allowed to stabalise before re-
adjusting.
10: Once the correct CO2 valve has been set at Minimum output the controller is returned to normal
operation by pressing and holding the MODE selection button for at least 3 seconds.
A flue gas analyser must be used to ensure that the correct combustion settings are achieved.
This is undertaken by inserting the analyser
‟s probe in to plugged hole within the flue collector of the
appliance or in the tapping in the flue immediately above the appliance if present.
The combustion setting required for all Wallcon appliances are as detailed in the following table.
Gas Type
115
125
160
Min
Max
Min
Max
Min
Max
CO2 Natural Gas (G20)
%
8.8
9.3
8.7
9.4
9.2
9.4
CO2 LPG (G31)
%
10.3
10.9
11.1
11.2
10.3
10.7
Label
Description
A
Minimum Output Adjustment Screw
B
Inlet Pressure Test Point
C
Maximum output Adjustment Screw
D
Burner Pressure Test Point
