Sterling TF-300 - Manual (Page 24)

24
MAINTENANCE
PERIODIC SERVICE 2. Turn off the manual gas valve and electrical power to
the unit heater.
3. To clean or replace the burners, remove burner
cover. Remove top strip from above burners. Lift
burners up and pull away from manifold to remove.
4. With the burners removed, wire brush the inside
surfaces of the heat exchanger.
5. Remove any dirt, dust, or other foreign matter from
the burners using a wire brush and/or compressed
air.
6. Reassemble the unit heater by replacing all parts in
reverse order.
7. Check the burner adjustment.
8. Check all gas control valves and pipe connections for
leaks.
9. 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
fl ame on the burners.
10. Inspect and service motor/fan assembly. To maintain
efficient air flow, inspect and clean the fan blades
and guard to prevent buildup of foreign matter.
11. Check lubrication instructions on motor. If oiling is
required, add 3 or 4 drops of electric motor oil as
follows:
a. Light Duty - After 3 years or 25,000 hours of
operation.
b. Average Duty - Annually after 3 years or 8,000
hours of operation.
c. Heavy Duty - Annually after 1 year or at least
1500 hours of operation.
Never over oil the motor or premature
failure may occur!
12. Check and test the operational functions of all safety
devices supplied with your unit.
NOTICE: The heater and vent system should be
checked once a year by a qualifi ed technician.
All Maintenance/Service information should be recorded
accordingly on the Inspection Sheet provided in this
manual.
Open all disconnect switches
and disconnect all electrical and gas supplies
and secure in that position before servicing unit.
Failure to do so may result in personal injury or
death from electrical shock.
Gas tightness of the safety shut-
off valves must be checked on at least an annual
basis.
To check gas tightness of the safety shut-off valves,
turn off the manual valve upstream of the appliance
combination control. Remove the 1/8 inch pipe plug on
the inlet side of the combination control and connect
a manometer to that tapping. Turn the manual valve
on to apply pressure to the combination control. Note
the pressure reading on the manometer, then turn the
valve off. A loss of pressure indicates a leak. If a leak
is detected, use a soap solution to check all threaded
connections. If no leak is found, combination control is
faulty and must be replaced before putting appliance
back in service.
Should maintenance be required, perform the following
inspection and service routine:
1. Inspect the area near the unit to be sure that there is
no combustible material located within the minimum
clearance requirements listed in this manual.
Under no circumstances should
combustible material be located within the
clearances specified in this manual. Failure to
provide proper clearance could result in personal
injury or equipment damage from fi re.