Sterling ME - Manual (Page 16)

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To remove the main burner drawer assembly (also refer
to Indoor Duct Furnace Installation and Service Manual)
for servicing the burners, proceed as follows:
1. Shut off the gas supply at the gas shutoff valve and
electrical power to the unit.
2. Break the union upstream of duct furnace gas valve
and loosen the union external to the furnace; swing
downward the piping to clear drawer.
3. Disconnect duct furnace gas valve wiring taking note
of all wire locations. Disconnect ignitor and fl ame
sensing probe wires at ignition control module and
any other wires.
4. Remove the locking screws holding the burner drawer
assembly in position.
5. Slide the burner drawer out of the duct furnace.
6. Removal of burners is accomplished by sliding burner
towards manifold, compressing locating spring, until
the rear of the burner clears slot in back of burner
drawer.
7. With burner drawer removed from duct furnace,
inspect the inside surfaces of the heat exchanger.
Wire brush if necessary.
8. Remove any dirt, dust or other foreign matter from
the burners using a wire brush and/or compressed
air. Insure all parts of the burner are unobstructed.
Inspect and clean pilot burner if necessary.
9. Reassemble the duct furnace by replacing all parts
in order.
10. Light unit per the unit lighting instructions.
11. Check the burner adjustment. See the “Primary Air
Adjustment” section of this manual.
12. Check all gas control valves and pipe connections for
leaks.
Under no circumstance should
combustible material be located within the
specifi ed clearances. Failure to provide proper
clearance could result in personal injury or
property damage from fi re.
13. Check the operation of the duct furnace gas valve by
lowering the setting of the thermostat, stopping the
operation of the duct furnace. The duct furnace gas
valve should close, extinguishing the pilot and main
burner fl ames.
14. Inspect and service the blower section of the system.
15. Inspect and check the operational functions of all
safety devices equipped with your unit to ensure that
all devices are performing adequately.
HIGH LIMIT AND/OR SAFETY LIMIT MAINTENANCE
To service or replace high limit and/or safety limit:
1. Turnoff the manual gas valve and electrical power to
the MS unit.
2. To service the High Limit:
a. Remove the Mounting Cover located on the
access side of the unit toward the rear (Air Inlet)
of the furnace section. Remove the mounting
plate from the side panel of the heat exchanger.
The mounting plate is part of the High Limit;
making note of wire locations for reconnecting.
b. Remove all electrical connections from the High
Limit; making note of wire locations for reconnecting.
c. Reassemble the High Limit by replacing all parts
in order; making sure the High Limit is making
proper surface contact when installed.
3. To service the Safety Limit:
a. Remove Mounting Cover located on the access
side of the unit toward the front (Air Outlet) of the
furnace section.
b. Remove all electrical connections from the Safety
Limit; making note of wire locations for
reconnecting.
c. Reassemble the Safety Limit by replacing all parts
in order; making sure the Safety Limit is making
proper surface contact with the side of the heat
exchanger.
4. Complete appropriate start-up procedure as given in
the “Start-Up” section of the MAIM manual.
5. Check Burner Adjustment.
6. Check gas control valves and pipe connection for leaks.
Under no circumstance should
combustible material be located within the
specifi ed clearances. Failure to provide proper
clearance could result in personal injury or
property damage from fi re.
7. Check operation of auto gas valve.
8. Check operation of safety devices.
9. Inspect and service blower section of system.