What does Carel E1 mean?

The E1 alarm indicates that probe S2 (the defrost/evaporator probe) has failed or lost contact with the Carel ir33 controller.

What does Carel IA mean?

The IA alarm is an immediate external alarm triggered when a digital input configured for external alarm contact opens.

What does Carel LO mean?

The LO alarm activates when the temperature measured by probe S1 (the room/cabinet probe) drops below the configured low-temperature alarm threshold for longer than the allowed delay period.

What does alarm 'E0' mean on a Carel IR33 controller?

E0 on the Carel IR33 is not a standard alarm — the display shows 'E0' during initial power-up while the controller runs its self-check. If E0 persists, it may indicate a EEPROM fault (corrupt configuration). Perform a factory reset by holding SET+UP+DOWN together for 10 seconds, then reprogram the controller from scratch.

How do I access the Carel pCO5 supervisor from a laptop?

Connect to the Carel pCO5 via Ethernet (LAN port on the pCO5+ board). Open the pCO web server at the pCO's IP address using a web browser. For older pCO3 units, use the RS485 port with Carel's 'pCOterm' software or a MODBUS TCP gateway. The default IP is 192.168.1.100 unless changed during commissioning.

How do I set up the Carel heaterCOMPACT humidifier?

The Carel heaterCOMPACT is configured via its built-in display. Key settings: target humidity setpoint, dead band (proportional band), probe type (0-1V, 0-10V, or NTC), and cylinder type (set when changing the steam cylinder). Run the 'flush' procedure when installing a new cylinder to prime the water pump and check for leaks before enabling automatic operation.

How do I update firmware on a Carel pCO controller?

Carel pCO firmware updates require a USB memory stick formatted to FAT32 with the firmware file placed in the root directory. Power off the pCO, insert the USB stick, power on while holding the USER button until the LED flashes. The controller copies the firmware automatically. Do not power off during the update. After the update, verify the firmware version in the pCO Service menu.

Refrigeration

Carel error codes, decoded.

Look up any Carel fault code below. Each one is grounded in Carel's own service documentation — the meaning, the symptoms, the causes, and the steps to clear it.

Quick answer

Carel controllers display family-specific fault codes. On ir33 / SmartCella / UltraCella refrigeration controllers, E1–E14 flag NTC and serial probe faults, HI / LO mark high and low temperature alarms, and EE signals an EEPROM error. On µChiller and pCO chiller controllers, AL01–AL77 cover compressor overloads, HP / LP pressure trips, and probe B1–B8 faults.

By Nichita Herput

Co-founder & CEO · Reviewed May 2026

Working on a Carel unit? The complete Carel code pack in your inbox — free.

Carel sits in our Refrigeration coverage. Every page here is transcribed from the manufacturer's manuals, not scraped from forums.

What error codes does Carel display?

Tap a code for the full breakdown — meaning, symptoms, causes, and fix steps.

not active ON probe 2 error= defrost automatic d0= 0 /1 / 4,F0= 1 E2 not active

active ON external alarm automatic [A4 = 1] [+A7] √ √ dOr active ON open door al

active ON low temperature alarm automatic [AL] [Ad] √ HI active ONhigh temperatu

not active ON unit parameter error not possible not active ON operating paramete

Probe S2 fault OFF OFF automatic unchanged unchanged unchanged changed un- YES N

Probe S3 fault OFF OFF automatic unchanged unchanged unchanged changed YES NO ch

E11

Serial probe S11 OFF OFF automatic duty seting (c4)unchanged unchanged un- YES N

E12

Serial probe S12 not updated OFF OFF automatic duty setting (c4) unchanged uncha

E13

Serial probe S13 not updated OFF OFF automatic duty setting (c4) unchanged uncha

E14

Serial probe S14 OFF OFF automatic duty setting (c4)unchanged unchanged un- YES

High temperature A ON ON automatic unchanged unchanged unchanged un- YES NO LO2

(rated current not reached) DRAIN ALARM E5 3 FILL ALARM 卡 MAINTENANCE WARNING (p

Get the complete Carel error-code pack by email

Every Carel code, meaning and first checks in one document you can save, print or forward. Free.

Common questions about Carel equipment

Other Refrigeration brands we cover

AskWhiz documents error codes for these manufacturers in the same vertical:

3M Accurex AHT Cooling Systems AKO Alco Controls Alfa Laval Arneg Aspera BAC Bitzer Bock Carrier Commercial Refrigeration