The following troubleshooting chart is
provided to serve as an aid for
identifying the cause of any system
malfunctions that may occur. Within
each chart are three columns: (1) the
Symptom column describes the
behavior the unit is exhibiting; (2) the
Probable Cause column identifies the
most likely sources of the malfunction;
and (3) the Recommended Action
column describes the suggested
action for correcting the problem.
Note: Use this troubleshooting chart
only as a guide for determining the
cause of mechanical failure or
malfunction. When mechanical
problems do occur, the Trane
Company recommends that qualified
service personnel be contacted to
help ensure proper diagnosis and
repair of the unit.
WARNING!
To avoid injury or death due to
electrical shock or entanglement
with moving parts, never open
access panel(s) to inspect or
service unit without first opening
unit disconnect switch.
Trouble Analysis
Symptom
Probable Cause
Recommended Action
Thermostat calls for heat, but unit
does not function.
Blown Fuse
Replace fuse; see Table 2 for proper
size. Determine cause for blown fuse.
Incorrect wiring
Check wiring connnections against
wiring diagram.
Thermal cutout open, causing heater
element and control circuit to
de-energize.
Check for the following:
a. Correct supply volts and phase.
b. Correct control wiring (i.e. heater
control must be thru thermostat
control wiring section only).
c. Power interruption to heater during
heater operation.
d. Restriction of air around heater.
e. 1 to 5-minute fan purge after
thermostat is satisfied (off).
Fan motor runs “hot”.
Dust or dirt accumulation on fan motor.
Clean fan motor and casing.
Dirt accumulation on louvers and
heating elements.
Clean louvers and between heating
elements.
Motor needs lubrication.
See Maintenance section of this
manual.
Fan motor runs, but there is no heat.
Element contactor is not operating
correctly.
Check wiring for open circuits.
Replace contactor if defective.
Element fuse blown.
Determine cause of blown fuse and
replace fuse. See Table 2 for fuse
sizes.
UHEC-IM-7A
17
