Technical data

26
6.3 initial lighting/commissioning (contd)
Turn on the appliance ON/OFF switch
TheMidimat begins with a two minute de-aeration program. After this 2 minute program the appliance
will start. If the Strata 3 does not start up and the message IGNITION FAILED is flashing on the status
indicator on the display panel, press the red re-set button to allow up to four further automatic ignition
attempts.
If ignition is still not established:
● Ensure the gas supply is correctly purged of air.
● Slightly increase the setting of the minimum burner output adjustment (a) and then press the red
re-set button.
● Approximately one minute after ignition, turn the green potentiometer on the boiler control panel to
setting ‘60’.
● Press the ‘Engineers’ button twice.
The status indicator shows 10 MIN LOW. The Strata 3 will now work for 10 minutes in
commissioning/testmode.
● Turn the green potentiometer to the left to 20°C: this corresponds to maximum output.
● Measure the CO
2
value directly for maximum output by analysing flue gas in the flue system.
Refer to table 6 below:
Type of Gas
Injector Diameter
(mm)
Minimum Output CO
2
%
Maximum Output CO
2
%
Natural Gas G20
220 10.8mm
330 13.0mm
7.8 - 8.4
8.9 - 9.4
LPG G31
220 7.5mm
330 9.7mm
10.0 - 10.6
10.9 - 11.4
Table 6
Note:
Function of adjustment screw for maximum output ("V")
Setting a higher figure increases output
Setting a lower figure reduces output
● Turn the green potentiometer to 60°C (minimum output) and then check/adjust combustion to
obtain value as shown in table 11.
Note: Function of adjustment screw for minimum output ("N")
Turning adjustment towards '+' figures increases output.
Turning adjustment towards '-' figures reduces output.
● Now turn the green potentiometer again to the left to 20°C (maximum output). Check again the
CO
2
value for maximum output.
● Correct the value, if required, with the maximum output screw ("V").
● Press the ‘Engineers’ button once. The Strata 3 switches back into automatic operation.
Note: After ten minutes in test mode, the Strata 3 automatically returns itself to automatic operation.