Jack BIG BJ90, Owner'S Manual

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SERVICE HINTS & TROUBLESHOOTING
Main blower vibrating when in use...
POSSIBLE CAUSE
Loose allen screw on squirrel cage
Defective motor or blower bearings
Weight on squirrel cage wheel moved in shipment
Main blower or blowers continue to run...
POSSIBLE CAUSE
Fan and limit control on unit is set too low
Defective fan and limit control
Improper wiring
Main blower or blowers won’t turn on...
POSSIBLE CAUSE
Improper wiring
Defective fan and limit control
Draft inducer motor staying on...
POSSIBLE CAUSE
Thermostat set higher than room temperature.
Short in thermostat wire
Home is not getting heat needed to satisfy wall thermostat
Draft inducer motor not turning on...
POSSIBLE CAUSE
Defective wall thermostat;
check by turning it above room temperature, draft blower
should turn on.
Smell an odor from the first fire in the home...
POSSIBLE CAUSE
New steel, small amounts of residue on steel
SOLUTION
Tighten the allen screw, be sure squirrel cage did not
move to one side or the other.
Return motor or blower for a replacement.
Try to adjust it or return blower for replacement.
SOLUTION
Remove cover on fan limit control and set dials to the
proper settings. Recommended temps: 160º on — 130º
off. NOTE: Never adjust fan and limit control by turning
dial itself (picture of fan limit dials.)
Check by turning one pointer down to where blower
should turn off, if they don’t, they need to be replaced.
Check wiring diagram.
SOLUTION
Check wiring diagram.
Replace fan and limit control.
SOLUTION
Set thermostat to setting lower than room temperature.
Check all wiring or replace thermostat
Furnace may be undersized for the size of your home.
SOLUTION
Replace thermostat or draft inducer motor.
SOLUTION
This will disappear in a matter of hours.
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