Lennox SL280UHNV Installation Instructions Manual page 44

Cleaning the Burner
NOTE - Use papers or protective covering in front of the
furnace during cleaning.
1 - Turn off both electrical and gas power supplies to
furnace.
2 - Label the wires from gas valve, thermal switch,
primary limit switch and make-up box then
disconnect them.
3 - Disconnect gas supply piping. Remove the screws
securing the air fuel plenum to the vestibule panel
and remove the air intake assembly (can stay
intact) / air fuel plenum assembly from the unit.
The air intake assembly and air fuel plenum can be
removed as one component.
Air Intake Assembly
Burner Removal For Cleaning Or Replacement
Air Gas Plenum
Gas Valve
4 - To clean burner and intake debris screen, run a
vacuum cleaner over the face of burners. Visually
inspect inside the burner. Remove any blockage.
5 - Reinstall air fuel plenum / air intake assembly
6 - Re-install gas supply and turn on electrical power
to furnace.
Gasket
(replace)
FIgURE 29
Page 44
Burner