Page 20
Cleaning the Heat Exchanger and Burners
NOTE - Use papers or protective covering in front of the fur
nace during cleaning.
1 - Turn off both electrical and gas power supplies to fur
nace.
2 - Remove flue pipe, top cap, flue chase and internal flue
pipe assembly from the unit.
3 - Label the wires from gas valve, rollout switches, prima
ry limit switch and make-up box then disconnect them.
4 - Remove the screws that secure the combustion air in
ducer/pressure switch assembly to the collector box.
Carefully remove the combustion air inducer to avoid
damaging blower gasket. If gasket is damaged, it must
be replaced to prevent leakage.
5 - Remove the collector box located behind the combus
tion air inducer. Be careful with the collector box gas
ket. If the gasket is damaged, it must be replaced to
prevent leakage.
6 - Disconnect gas supply piping. Remove the screw se
curing the burner box cover and remove cover. Re
move the four screws securing the burner manifold as
sembly to the vestibule panel and remove the assem
bly from the unit.
7 - Remove screws securing burner box and remove
burner box.
8 - Remove screws from both sides, top and bottom of
vestibule panel.
9 - Remove heat exchanger. It may be necessary to
spread cabinet side to allow more room. If so, remove
five screws from the left side or right side of cabinet.
See figure 16.
EL280DF BURNER, C.A.I ASSEMBLY &
HEAT EXCHANGER REMOVAL
FIGURE 15
gasket
collector box
orifice plate
internal flue pipe
pressure switch
combustion air inducer
burners
manifold and gas valve
retention rings
cross over
heat exchanger
flue chase
gasket
rollout switch
ignitor
sensor
