TTJ-0198 (10/97) (Page 33 of 64)
Unit does not heat
adequately.
Outdoor thermostat does not cut off
compressor at the preselected tem-
perature and bring on heating element.
Fresh air or exhaust door open.
Dirty filter.
Unit undersized.
Defective thermostat - replace.
Check if operating properly. Instruct customer
on proper use of control.
Clean as recommended in Owner’s Manual.
Check heat rise across coil. Refer to perfor-
mance data sheet on heat rise at various
outdoor ambients. If heat rise is satisfactory,
check if insulation can be added to attic or
walls.
PROBLEM POSSIBLE CAUSE TO CORRECT
PROBLEM POSSIBLE CAUSE TO CORRECT
Heating capillary tube partially re-
stricted.
Check valve leaking internally.
Reversing valve failing to shift com-
pletely – bypassing hot gas.
Cooling adequate –
heating insufficient.
Check for partially starved outer coil. Replace
heating capillary tube.
Switch unit several times from heating to
cooling. Check temperature rise across coil.
Refer to specification sheet for correct tempera-
ture rise.
De-energise solenoid coil, raise head pressure,
energize solenoid to break loose. If valve fails
to make complete shift, replace valve.
PROBLEM POSSIBLE CAUSE TO CORRECT
Compressor will not
turn off and operate
on heating element
only during low
outside ambients.
Outdoor thermostat.
(Applicable models.)
Refer to the heating data on applicable models
for the preselected temperature the compressor
shuts off and the electric element is energized.
Check fuse link for continuity. If defective,
replace.
Check amperage draw of element. If no amper-
age, replace.
Check voltage to element. If voltage is okay,
check wiring.
Defective coil. Test coil for continuity.
Compressor shuts
off on outdoor
thermostat but
element does not
heat.
Fuse link.
Heating element shorted.
Incorrect wiring.
Heat relay or heater contactor coil
open.
PROBLEM POSSIBLE CAUSE TO CORRECT
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