JOHNSON CONTROLS
14
FORM ET130.13-NOM3 (708)
TROUBLESHOOTING GUIDELINES
PROBLEM POSSIBLE CAUSE CORRECTIVE ACTION
Motor Fails to Start
Blown fuse or open circuit breaker
Replace fuse or reset circuit breaker; verify and correct
source of overload.
Shipping Cardboard insert in fan wheel Remove insert and restart.
Improper wiring connections Check wiring with diagram supplied on unit.
Improper current supply
Compare actual supply power with motor nameplate
recommendations. Contact power company for adjust-
ments.
Mechanical failure Check motor and confi rm rotates freely.
Motor Overheats
Overloaded motor Reduce load or replace with a larger motor (refer factory).
Motor fan is clogged with dirt preventing
proper ventilation
Remove fan cover, clean fan and replace cover. May be
necessary to replace motor.
Lack of required external static pressure Add required external static pressure.
Excessive Motor
Noise
Motor mounting bolts loose Tighten motor mounting bolts.
Fan wheel rubbing on fan housing Align wheel in housing.
Loose fan wheel Align and tighten.
SCR set too low
Select lower tap to Reduce motor speed and re-adjust
fan SCR.
Low Coil Capacity
Incorrect airfl ow Check fan’s operating conditions.
Incorrect GPM Check water pumps, valves and lines for obstructions.
Dirty coil fi ns Clean coil Fins.
Dirty fi lter (where applicable) Replace fi lter.
Incorrect water temperature Provide proper water temperature.
Heater Does Not
Operate
No Power Check Disconnect.
No Control Voltage
Check transformer and transformer fusing (if applicable)
replace if necessary.
Blown Fuse Replace fuse.
Open Limit (primary or secondary)
Replace limits or reset as applicable.
Check for continuity across limit to determine if open,
replace as necessary.
Airfl ow Incorrect Direction
Check sensing tube, red tube = high and black tube =
low, rotate if needed.
Low External Static Pressure
Increase airfl ow to obtain a minimum of .1 in. w.c. exter-
nal static.
Damaged elements
Check for open or damaged elements and replace as
necessary.
Low or High Tem-
perature Rise
Incompatible Thermostat or Controller
Check Wiring.
Check for compatibility.
Problems with Additional Stages
Check location of thermostat; might be installed in a
“too hot” or “too cold” location. Check heat outputs on
controller.
Check contactors for open coil.
Check for damaged elements.
Incorrect CFM Check for blocked duct or location of heater.
Heater with SSR
Does Not Operate
Incorrect Signal Applied Verify signal input.
Interface Board Fuse Blown Replace fuse.
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