315AAV
Check Safety Controls
The flame sensor, gas valve, and pressure switch were all checked in the
1.Check Main Limit Switch
This control shuts off combustion system and energizes
a.Run furnace for at least 5 minutes.
b.Gradually block off return air with a piece of card- board or sheet metal until the limit trips.
c.Unblock return air to permit normal circulation.
d.Burners will
2.Check draft safeguard switch. The purpose of this control is to cause the safe shutdown of the furnace during certain blocked vent conditions.
a.Verify vent pipe is cool to the touch.
b.Disconnect power to furnace and remove vent con- nector from furnace vent elbow.
c.Restore power to furnace and set room thermostat above room temperature.
d.After normal
e.Furnace should cycle off within 2 minutes. If gas does not shut off within 2 minutes, determine reason draft safeguard switch did not function properly and correct condition.
f.Remove blockage from furnace vent elbow.
g.Switch will
h.
NOTE: Should switch remain open longer than 3 minutes, furnace control board will lockout the furnace for 3 hours. To reset furnace control board, turn thermostat below room temperature or from HEAT to OFF and turn
3.Check Pressure Switch(es)
This control proves operation of the draft inducer blower.
a.Turn off
b.Disconnect inducer motor lead wires from wire har- ness.
c.Turn on
d.Set thermostat to “call for heat” and wait 1 minute. When pressure switch is functioning properly, hot sur- face igniter should NOT glow and control diagnostic light flashes a status code 32. If hot surface igniter glows when inducer motor is disconnected, shut down furnace immediately.
e.Determine reason pressure switch did not function properly and correct condition.
f.Turn off
g.Reconnect inducer motor wires, replace outer door, and turn on
h.Blower will run for 90 seconds before beginning the call for heat again.
i.Furnace should ignite normally.
Checklist
1.Put away tools and instruments. Clean up debris.
2.Verify that switches
3.Verify that blower and burner access doors are properly in- stalled.
4.Cycle test furnace with room thermostat.
5.Check operation of accessories per manufacturer’s instruc- tions.
6.Review User’s Guide with owner.
7.Attach literature packet to furnace.
SERVICE AND MAINTENANCE
PROCEDURES
!WARNING
FIRE, INJURY OR DEATH HAZARD
Failure to follow this warning could result in personal injury, death and/or property damage.
The ability to properly perform maintenance on this equipment requires certain knowledge, mechanical skills, tools, and equipment. If you do not possess these, do not attempt to perform any maintenance on this equipment other than those procedures recommended in the User’s Manual.
!CAUTION
ENVIRONMENTAL HAZARD
Failure to follow this caution may result in environmental pollution.
Remove and recycle all components or materials (i.e. oil, refrigerant, control board, etc.) before unit final disposal.
!WARNING
ELECTRICAL SHOCK, FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury or death, or property damage.
Before installing, modifying, or servicing system, main electrical disconnect switch must be in the OFF position and install a lockout tag. There may be more than one disconnect switch. Lock out and tag switch with a suitable warning label. Verify proper operation after servicing.
!CAUTION
ELECTRICAL OPERATION HAZARD
Failure to follow this caution may result in improper furnace operation or failure of furnace.
Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous operation.
General
These instructions are written as if the furnace is installed in an upflow application. An upflow furnace application is where the blower is located below the combustion and controls section of
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