15. Allow the flame safety control unit (item A1) to cycle through the start up sequence; check
that the pressure switch (P1) has changed over from the `no air’ to the air proved position.
If it hasn’t, adjust the combustion air supply so as to provide satisfactory burner air
pressure. Check that the ignition and pilot solenoid valves are electrically energised at the
correct time and in the correct sequence. The burner flame safety control unit should then
lockout.
16. Open the manual pilot valve (item V6)
17. Fit Micro-ammeter into circuit with the flame sensor.
18. Reset the burner lockout button; the burner will cycle and the pilot flame should light. It
may be necessary to start the light up sequence (reset) several times so as to remove air
from the pilot line and to adjust the pilot flame to the correct size. Check the pilot flame
signal on the micro-ammeter.
19. Note that the burner will go to lockout after each attempt to light the pilot.
20. Half open the manual test valve (item V2). Reset the burner lockout button. The burner
should cycle and light up onto the main flame.
21. Slowly open up the manual test valve (item V2) to the full position and adjust the main gas
governor (item G2) to produce the required flame size. With the burner on full fire
(temperature control calling heat) check that the gas pressure at the nozzle is as specified
for the required thermal/fuel rating, this will be indicated on the burner data label and
can also be established from the nozzle flow graph included with this manual.
22. Check the main flame signal on the micro-ammeter.
23. Turn the combustion air pressure switch (item P1) upwards so that the burner shuts down.
Note the adjustments in air pressure and reduce the switch setting by 25%.
24. Whilst the burner is operating remove the electrical connections from the flame sensor.
Check that the burner flame safety control locks out immediately and that the gas supply is
automatically shut off.
25. Whilst the burner is operating, block the combustion air supply so that the pressure switch
P1 switches to the ‘no air’ position, checking that the burner shuts down.
Initial Light Up (Commissioning)
Comtherm Ltd
Installation & Maintenance Manual
Page 08
Burners, Heaters & Combustions Systems
