Sterlco Royal Series Compact Temperature Control Unit User Manual
Page 47

Royal Series Water Temperature Control Units
Page 47
Condition Possible
cause Solution
Defective heater contactor.
Visually inspect coil and 
contacts; repair/replace 
defective contactors. 
Defective immersion heater.
Check resistance on all three (3) 
legs of the heater with an ohm 
meter. If not all equal, contact 
factory for replacement heater. 
Controller heat output open.
Check the heater output with an 
ohm meter to ground. It should 
read in the mega-ohm range. 
Infinite or zero readings indicate 
a defective output. 
Heater contactor is not 
energizing, but 
HEAT
LED is on.
Set process temperature to 
maximum and check for control 
voltage at heater contactor. 
Immersion heater elements 
dirty. 
Remove heater and clean 
elements. 
Check heater tank for 
scorched/discolored paint. 
Check resistance on all three (3) 
legs of the heater with an ohm 
meter. Replace heater as 
required. 
Immersion heater element is 
burned out. 
Check for balanced amp draws, 
and supply voltage. If not 
present replace immersion 
heater. 
OUT1
indicator is on, but no
voltage on heater contact.
Replace relay board on 
controller. 
Cooling valve is leaking.
Dismantle valve and clean out.
Solenoid valve is not operating, 
but 
COOL
LED is on.
Set process temperature to 
minimum and check for 
magnetism on top of solenoid 
coil. 
Magnetism on coil.
Clean coil.
Unit does not heat/cannot 
achieve set point. 
Faulty/dirty solenoid valve.
Press
VENT
button several times
to flush the valve.
