– 20 –
START-UP (continued)
FINAL CHECKOUT
Run the unit sequentially through its stages of heating.
One proper unit operation is verified, perform these final
steps:
1.
Inspect the unit for debris and/or misplaced tools
and hardware.
MAINTENANCE
Open all disconnect switches and
secure in that position before servicing unit.
Failure to do so may result in personal injury or
death from electrical shock.
Rooftop duct furnaces have been developed for
outdoor installation. Should maintenance be required,
perform the following inspection and service routine:
Inspect area near the unit to be sure that there is no
combustible material located within minimum
clearance requirements (refer to Figures 1, 2 and 6).
Service panels provide easy access to the burner
controls. To remove the service door, refer to “Access
Panel Removal” section (at the beginning of this
manual).
The pilot burner can be serviced by removing the pilot
plate from the main burner assembly.
To remove the main burner drawer assembly for
servicing the burners, proceed as follows:
1.
Shut off the main gas valve and electrical power to
the gas duct furnace.
2.
To slide out the burner drawer, the following two
procedures (a or b) may be chosen depending on
the complexity of the unit's controls:
a.) Disconnect the pilot burner gas tube. Break
the union between the automatic gas valve
and the burner manifold. Also break the union
on the discharge air end of the furnace (inside
the unit). Loosen the union located directly
outside of the furnace's bottom panel (refer to
figure 9b). Swing down this end of the piping
to clear the bottom of the burner drawer. The
control and piping assembly may be tied out of
the way of the pull-out drawer.
b.) Disconnect all wiring to the unit's controls.
Break the union located in the discharge
end of the furnace; loosen the external union,
and swing piping clear of the bottom of the
drawer (same procedure as a).
3.
Remove the locking screws holding the burner
drawer in position.
4.
Slide the drawer out of the furnace.
5.
Burners can be removed from the drawer by
raising the front of the burner and pushing it
against the hold-in spring until the front of the
burner comes out of the slot.
2.
Disable air handling blower. Fire unit and confirm
that high limit switch shuts gas off within
approximately 5 minutes. Re-enable air handling
blower.
3.
Be sure all gas valves and controls are in the
operating position if the unit will be operating
immediately
4.
Secure all exterior panels in place.
6.
To clean or replace the main burners, slide out the
pullout drawer, and compress the spring by
moving the burner toward the manifold. Slide the
opposite end of the burner downward from the
locating slot while retaining spring is still
compressed. Pull the burners upward and out.
7.
Remove any dirt, dust or other foreign matter from
the burners using a wire brush and/or compressed
air. Ensure that all parts are unobstructed. Inspect
and clean pilot burner if necessary.
8.
Reassemble the gas duct furnace by replacing all
parts in order.
9.
Complete the appropriate unit start-up procedure
as given in the “Start-Up” section of this manual.
10. Check the burner adjustment. See the “Primary Air
Shutter Adjustment” section of this manual.
11. Check all gas control valves and pipe connections
for leaks.
Under no circumstances should
combustible material be located within the
clearances specified in Figure 6. Failure to
provide proper clearance could result in
personal injury or equipment damage from fire.
12. Check the operation of the automatic gas valve by
lowering the setting of the thermostat, stopping the
operation of the gas duct furnace. The gas valve
should close tightly, completely extinguishing the
flame on the main burners.
13. Check the operation of all safety devices.
14. Inspect and service the blower section of the
system.
The outdoor unit should be thoroughly checked before
the start of the heating season. Check the air through-
put as an added precaution to stay within the specified
temperature limits.
If the unit is used with cooling equipment, periodic
maintenance should be scheduled throughout the
year.
