Which Carel controller is on your walk-in — and what do its codes mean?
Carel controllers are fitted by walk-in and refrigeration OEMs worldwide — most commonly the ir33 / ir33+ family and the smaller PJ Easy (PJEZ), the compact digital thermostats you'll find running boxes from many different builders. Their code language is compact: E-codes are probe faults (E0 room probe, E1 defrost probe, E2 condenser probe), HI and LO are the temperature alarms, dor/dOr the door alarm, Ed/Ed1 means a defrost timed out before clearing the coil, and the condenser pair — lowercase cht as the dirty-condenser early warning, uppercase CHt as the hard alarm — is the difference between a cleaning reminder and a compressor at risk. A code that fools everyone: dEF or dF isn't a fault at all, just the display's way of saying a defrost is running.
Carel controllers on HACCP-equipped installs also log HA/HF temperature-excursion events. Find your exact code below for the documented meaning, safe checks, and the technician threshold.
Which Carel controller do you have?
| Controller | Alarm codes covered | Page |
|---|---|---|
| Carel ir33 / ir33+ Compact panel display; the code shows in place of the temperature with a bell icon. | 24 alarm codes: rE, E0, E1, E2, E3, HI, LO, IA, dA, dor and 14 more | Full list → |
| Carel PJ Easy (PJEZ) Small Carel thermostat; E0/E1/E2, dOr and cht/CHt alternate with the temperature. | 14 alarm codes: E0, E1, E2, IA, dOr, LO, HI, EE, EF, Ed and 4 more | Full list → |
Carel ir33 / ir33+
The Carel ir33 and ir33+ are among the most widely used electronic refrigeration controllers in the world, fitted by walk-in box and case OEMs and installed by contractors as replacement controls on coolers and freezers of every brand. The display normally shows temperature; a fault alternates a short code with the reading — E-codes for probe failures, HI/LO for temperature alarms, dor for the door, cht/CHt for the condenser, HA/HF for HACCP excursion logs. Practical tip: lowercase and uppercase matter — cht is an early dirty-condenser warning you can act on with a coil cleaning, while CHt is the escalated manual-reset alarm that means the warning stage was missed.
All 34 Carel ir33 / ir33+ codes — meanings, checks, diagnosis and parts →
Carel PJ Easy (PJEZ)
The Carel PJ Easy (PJEZ) is a small, low-cost panel-mount controller that box and case OEMs fit widely to coolers, freezers, and walk-in panels, and that contractors commonly install as a replacement thermostat. It uses short two- or three-character codes that alternate with the temperature reading: E0/E1/E2 for failed probes, HI/LO for temperature alarms, dOr for the door, cht/CHt for a dirty condenser, EE/EF for parameter memory errors. Practical tip: dF flashing on the display just means a defrost is running — it's normal status, not a fault, so wait out the cycle before assuming something is wrong.
All 15 Carel PJ Easy (PJEZ) codes — meanings, checks, diagnosis and parts →
Every Carel code, by controller
Carel ir33 / ir33+:
Carel PJ Easy (PJEZ):