4-9
D
YES
B
Check contactors K7 thru K10. Check
wiring for loose connections. Check
continuity between the grey lead on
each contactor and the grey lead to the
HEATING light.
Replace the
defective heating
elements
NO
YES
Check heating
elements as
described in 4.3.
Are they good?
YES
Replace the fuse(s)
and determine the
cause for blowing.
NO
Are heating
element fuses
blown?
YES
C
Replace the
temperature
probe.
YES
Replace the module.
Test the
temperature control
module as described
in 4.5. Is the module
defective?
NO
Replace the
potentiometer.
NO
Test the temperature
set potentiometer
as described in 4.4. Is
the potentionmeter
defective?
YES
NO
Test the temperature
probe as described in 4.6.
Is the temperature probe
defective?
NO
Does HEATING
light go out when
thermostat is set above
oil temperature?
Verify continuity of the leads
which provide 24 VAC power,
and the potentiometer and probe
signals to the module.
YES