Page 30
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
assembly 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 28.
SL280DFV BURNER, COMBUSTION AIR INDUCER ASSEMBLY &
HEAT EXCHANGER REMOVAL
FIGURE 27
heat exchanger
gasket
collector box
orifice plate
internal flue pipe
pressure switch
combustion air inducer
burners
burner box assembly
burner box cover plate
manifold and gas valve
gasket
retention rings
cross over
heat exchanger
gasket
collector box
orifice plate
internal flue pipe
pressure switch
combustion air inducer
burners
burner box assembly
burner box cover plate
manifold and gas valve
gasket
flue chase
gasket
ignitor
rollout switch
sensor
