User guide
Watlow EZ-ZONE
®
 RMH Module  • 147 •  Appendix
Troubleshooting Alarms, Errors and Module Issues
Indication Description Possible Cause(s) Corrective Action
Alarm won’t clear or 
reset
Alarm will not clear or reset 
with keypad or digital input 
• Alarm latching is active  
• Alarm set to incorrect output  
• Alarm is set to incorrect source  
• Sensor input is out of alarm set point 
range 
• Alarm set point is incorrect  
• Alarm is set to incorrect type  
• Digital input function is incorrect 
• Reset alarm when process is within 
range or disable latching 
• Set output to correct alarm source 
instance 
• Set alarm source to correct input in-
stance 
• Correct cause of sensor input out of 
alarm range 
• Set alarm set point to correct trip 
point 
• Set alarm to correct type: process, de-
viation or power 
• Set digital input function and source 
instance 
Alarm won’t occur Alarm will not activate output  • Alarm silencing is active 
• Alarm blocking is active 
• Alarm is set to incorrect output  
• Alarm is set to incorrect source  
• Alarm set point is incorrect  
• Alarm is set to incorrect type
• Disable alarm silencing, if required 
• Disable alarm blocking, if required 
• Set output to correct alarm source 
instance 
• Set alarm source to correct input in-
stance 
• Set alarm set point to correct trip 
point 
• Set alarm to correct type: process, de-
viation or power
Alarm Error
[AL;E1] [AL;E2] 
[AL;E3] [AL;E4] 
[AL;E5] [AL;E6] 
[AL;E7] [AL;E8]
[AL;E9] [AL;10] 
[AL;11] [AL;12] 
[AL;13] [AL;14] 
[AL;15] [AL;16]
[AL;17] [AL;18] 
[AL;19] [AL;20] 
[AL;21] [AL;22] 
[AL;23] [AL;24]
Alarm state cannot be deter-
mined due to lack of sensor 
input 
• Sensor improperly wired or open 
• Incorrect setting of sensor type 
• Calibration corrupt 
• Correct wiring or replace sensor 
• Match setting to sensor used 
• Check calibration of controller 
Alarm Low
[AL;L1] [AL;L2] 
[AL;L3] [AL;L4] 
[AL;L5] [AL;L6] 
[AL;L7] [AL;L8]
[AL;L9] [AL;10] 
[AL;11] [AL;12] 
[AL;13] [AL;14] 
[AL;15] [AL;16]
[AL;17] [AL;18] 
[AL;19] [AL;20] 
[AL;21] [AL;22] 
[AL;23] [AL;24]
Sensor input below low alarm 
set point 
• Temperature is less than alarm set 
point 
• Alarm is set to latching and an alarm 
occurred in the past 
• Incorrect alarm set point 
• Incorrect alarm source
• Check cause of under temperature  
• Clear latched alarm 
• Establish correct alarm set point 
• Set alarm source to proper setting
Alarm High
[AL;h1} [AL;h2] 
[AL;h3] [AL;h4] 
[AL;h5} [AL;h6] 
[AL;h7] [AL;h8]
[AL;h9] [AL;10] 
[AL;11] [AL;12] 
[AL;13] [AL;14] 
[AL;15] [AL;16]
[AL;17] [AL;18] 
[AL;19] [AL;20] 
[AL;21] [AL;22] 
[AL;23] [AL;24]
Sensor input above high 
alarm set point 
• Temperature is greater than alarm 
set point 
• Alarm is set to latching and an alarm 
occurred in the past 
• Incorrect alarm set point 
• Incorrect alarm source 
• Check cause of over temperature  
• Clear latched alarm  
• Establish correct alarm set point 
• Set alarm source to proper setting 










