www.desatech.com
115423-01A
7
TROUBLESHOOTING
Continued
7. Replace removed plug in hole. Perform a trial
operation.
8. If repeated resetting of the thermal limit switch
is required, have the product serviced by an
authorized service center.
OBSERVED FAULT
Tubular heating element heats up but
no rush of warm air is felt at outlet vents
Rotate fan by hand to determine if fan
rotates easily
Fan is difficult
Fan rotates easily
to rotate
by hand
1 Fan or motor
3 Open motor coil
obstructed
2 Dry motor bearing
Test Procedure
1. Fan or Motor Obstructed
Remove obstruction. Clean heater.
2. Dry Motor Bearing
If the fan is difficult to turn, then motor bearings
are defective. Bearings are permanently lubricated,
therefore motor should be replaced.
3. Open Motor Coil
Disconnect motor wires (black and white). Attach
the ohmmeter leads to the motor wire terminals.
Using the 0 to 200 ohm scale, measure the resis-
tance of the motor coil. If the resistance is not
approximately 6.0 to 6.4 ohms at 73° F, the motor
is defective and should be replaced.
Note:
Resistances may vary due to motor
temperature.
Figure 6 - Testing Motor
OBSERVED FAULT
Motor starts and runs but cool air is felt
Does tubular heating element heat up?
No
Yes
WARNING:
WARNING:
Hot Surface!
Hot Surface!
1 Look for defective 3 Check for blocked
tubular heating
air intake openings
element
2 Open tubular heating
element
Test Procedure
1. Look for Defective Tubular Heating
Element
After approximately 2 minutes the tubular heat-
ing element should glow a dull red when placed
in a dark area.
2. Open Tubular Heating Element
Disconnect element wires (black and white).
Attach the ohmmeter leads to the element wire
terminals. Using the 0 to 200 ohm scale, measure
the resistance of the element. If the resistance is
not 8.5 to 11 ohms at 73° F the element is defective
and should be replaced.
Note:
Resistances may
vary due to element temperature.
3. Check for Blocked Air Intake Openings
Check for blockages around vent openings at bot-
tom of heater (see Figure 5, page 6).
Figure 7 - Testing Heating Element
