Lennox ML193DFE Series Unit Information page 47

Cleaning the Burner Assembly
1 - Turn off electrical and gas power supplies to furnace.
Remove upper and lower furnace access panels.
2 - Disconnect the 2-pin plug from the gas valve.
3 - Remove the burner box cover.
4 - Disconnect the gas supply line from the gas valve.
Remove gas valve/manifold assembly.
5 - Mark and disconnect sensor wire from the sensor.
Disconnect 2-pin plug from the ignitor at the burner
box.
6 - Remove four screws which secure burner box
assembly to vest panel. Remove burner box from
the unit.
7 - Use the soft brush attachment on a vacuum cleaner
to gently clean the face of the burners. Visually
inspect the inside of the burners and crossovers for
any blockage caused by foreign matter. Remove
any blockage.
8 - Reconnect the sensor wire and reconnect the 2-pin
plug to the ignitor wiring harness.
9 - Reinstall the burner box assembly using the existing
four screws. Make sure that the burners line up in
the center of the burner ports.
10 - Reinstall the gas valve manifold assembly.
Reconnect the gas supply line to the gas valve.
Reinstall the burner box cover.
11 - Reconnect 2-pin plug to gas valve.
12 - Replace the blower compartment access panel.
13 - Refer to instruction on verifying gas and electrical
connections when re-establishing supplies.
14 - Follow lighting instructions to light and operate
furnace for 5 minutes to ensure that heat exchanger
is clean and dry and that furnace is operating
properly.
15 - Replace heating compartment access panel.
Page 47