Sterling TD - Manual (Page 28)

28
MAINTENANCE
PERIODIC SERVICE
NOTICE: The duct furnace 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 at the end
of 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 1/8 in. pipe plug on the inlet side of the
combination control and connect a manometer to that tap.
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 soap solution
to check all threaded connections. If no leaks is found,
combination control is faulty and must be replaced before
putting appliance back in service.
It is the service technician’s
responsibility to check all safety controls! Check
and test the operational functions of all safety
devices supplied with this unit, and ensure that
all are operating effectively. Failure to do so could
result in unsafe conditions and may result in
death, serious injury or property damage.
All Maintenance/Service info should be recorded
accordingly on the Inspection Sheet provided on back
cover of this manual. 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
safety clearance requirements listed in this manual.
Under no circumstances should
combustible material be located within the
clearances specifi ed in this manual. Failure to
provide proper clearance could result in personal
injury or equipment damage from fi re.
2. Turn off the manual gas valve and electrical power to
the duct furnace.
3. Remove access panel.
4. To clean or replace the burners:
a. Disconnect the gas inlet pipe.
b.
Remove the four (4) screws that hold the manifold
in place, and remove the manifold, gas valve, and
gas inlet pipe assembly.
c. Visually inspect the burners and heat exchanger
tubes for signs of soot or debris.
d. If burners require cleaning, they can be cleaned
with a wire brush and/or compressed air.
e. If inside surface of heat exchanger tubes require
cleaning, remove manifold bracket sub-assembly
by removing four (4) screws holding it in place.
5. With the burners removed, use a fl exible wire brush
and compressed air to clean the inside surfaces of
the heat exchanger tubes.
6. Inspect air inlet for blockage/debris. Clear if any found.
7. Reassemble the duct furnace by replacing all parts
in reverse order.
8. Complete the appropriate unit start-up procedure as
given in the Operation section of this manual (see
lighting instruction plate on the access side of the
unit).
9. Check all gas control valves and pipe connections
for leaks.
10. 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.
11. Check lubrication instructions on power vent motor.
If oiling is required, add 1 or 2 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
1,500 hours of operation.
Never over oil the power vent motor
or premature failure may occur!
12. Check and test the operational functions of all safety
devices supplied with your unit.