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Limit Control Switch
The limit control switch(es) is factory-set and is not
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straight, or any combination of these directions. When
30/105 units are is installed in an inverted position, lou-
vers must be removed and rotated 180 degrees as shown
in the installation section.
Flame Rollout Switch
This normally closed switch opens on a temperature rise.
See the parts arrangement for location. These switches
are not adjustable.
Service
CAUTION
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any maintenance or service operations on this unit.
Remember to follow lighting instructions when putting
unit back into operation after service or maintenance.
The unit heater and vent system shall be inspected once
a year by a licensed professional service technician, or
equivalent.
BURNERS
1 -
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appearance during the heating season.
2 - Before each heating season examine the burners for
any deposits or blockage that may have occurred.
3 - Clean burners as follows:
a.
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b. Disconnect gas supply piping, high tension and
sensor leads. Remove gas manifold. Remove
burner box top. Remove burner cluster assembly.
c. Clean burners as necessary. Make sure that
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crossover. Check spark gap on electrode and
adjust if required. The gap should be between
0.110” and 0.140” (3mm to 4mm). The gap may
be checked with appropriately sized twist drills or
feeler gauges.
d. Reinstall burner cluster assembly, burner box
top, gas manifold, high tension and sensor leads.
Reconnect gas supply piping.
e. Restore electrical power and gas supply. Follow
lighting instructions to light unit. Check burner
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FLUE PASSAGEWAY AND FLUE BOX
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cleaned prior to each heating season. The sequence of
operation should be as follows:
1 -
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2 - Disconnect combustion air inducer wiring.
3 - Remove combustion air inducer assembly. Remove
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4 - Remove burners as described in “Burners” section.
5 - Clean tubes with a wire brush.
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gaskets should also be replaced during reassembly.
7 - Restore electrical power and gas supply. Follow
lighting instructions to light unit. Check operation of
unit.
COMBUSTION AIR INDUCER
Under normal operating conditions, the combustion air in-
ducer should be checked and cleaned prior to the heating
season with the power supply disconnected. Use a small
brush to clean inducer wheel.
ELECTRICAL
1 - Check all wiring for loose connections.
2 - Check for correct voltage at unit (unit operating).
3 - Check amperage draw.
FLUE AND CHIMNEY
Check all vent and vent connector joints for tightness. En-
sure that connections are sealed and that there are no
blockages.
FAILURE TO OPERATE
If unit fails to operate check the following:
1 - Is thermostat calling for heat?
2 - Is main disconnect closed?
3 - Is there a breaker tripped or a fuse blown?
4 - Is gas turned on at meter?
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6 - Is unit ignition system in lock out? If unit locks out
again, call service technician to inspect unit.
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passage and outlet.
SAFETY SHUT-OFF VALVE TEST
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1 -
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2 - Set the thermostat to call for heat.
3 - System begins normal sequence of operation.
4 - After approximately 30 seconds (pre purge period)
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powered.
Combustion Air Pressure Switch
This pressure switch checks for proper combustion air
inducer operation before allowing an ignition trial. The
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high altitude applications, see the Engineering Handbook.