Troubleshooting - PENN Controls - A421ABD - A421AED - Electronic Temperature Control - A421 Off‐Cycle Defrost Model

A421 Series Electronic Temperature Controls with Off-Cycle Defrost Installation Guide

Product name
A421 Off‐Cycle Defrost Model
Document type
Installation Guide
Document revision
E
Revision date
2022-08-25

A421 Series Controls display fault codes on the LCD as described in Table 1.

Table 1. Fault codes
Fault code Definition System status Solution
SF flashing alternately with OP Open temperature sensor or sensor wiring Output functions according to the selected SF mode See Troubleshooting procedure. Cycle power to reset the control.
SF flashing alternately with SH Shorted temperature sensor or sensor wiring Output functions according to the selected SF mode See Troubleshooting procedure. Cycle power to reset the control.
EE Program failure Output is off To reset the control, press MENU. If problems persist, replace the control.