Bryant 315AAV Service And Maintenance Procedures, Check Safety Controls, Checklist, General

315AAV

Check Safety Controls

The flame sensor, gas valve, and pressure switch were all checked in the Start-up procedure section as part of normal operation.

1.Check Main Limit Switch

This control shuts off combustion system and energizes air-circulating blower motor, if furnace overheats. By us- ing this method to check limit control, it can be established that limit is functioning properly and will operate if there is a restricted return-air supply or motor failure. If limit control does not function during this test, cause must be determined and corrected.

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 re-light when furnace cools down.

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 start-up, allow furnace to operate for 2 minutes, then block vent elbow in furnace 80 percent of vent area with a piece of flat sheet metal.

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 auto-reset when it cools.

h.Re-install vent connector.

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 115-v power OFF, then back ON.

3.Check Pressure Switch(es)

This control proves operation of the draft inducer blower.

a.Turn off 115-v power to furnace.

b.Disconnect inducer motor lead wires from wire har- ness.

c.Turn on 115-v power to furnace.

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 115-v power to furnace.

g.Reconnect inducer motor wires, replace outer door, and turn on 115-v power.

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 SW1-1 and SW1-6 are OFF and oth- er setup switches are set as desired. Verify that switches

SW1-7 and SW1-8 for the blower OFF DELAY are set as desired per Table 10.

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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