What do Carel PJ Easy (PJEZ) alarm codes mean?
Part of the Carel walk-in controller codes hub. Same brand, different controller: Carel ir33 / ir33+.
Short answer: when a PJ Easy alarms, the code flashes alternating with the temperature and — where fitted and enabled — the buzzer and alarm relay switch on. E0, E1 and E2 are probe errors (control, defrost, condenser/product), HI/LO temperature alarms, dOr the door, IA an external alarm, cht/CHt a dirty condenser, Ed a defrost that ended on time, EE/EF parameter errors and EtC the clock. Every alarm clears itself once its cause is gone except CHt, which needs a manual reset.
Which machines use it?
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.
How do you read and clear the display?
Press SET to mute the buzzer; the code and the alarm relay only go off when the cause has been resolved. To reset CHt, switch the controller off and on with the UP button (hold it 3 seconds) or disconnect the power — after cleaning the condenser. dF on the display just means a defrost is running.
How do you enter the parameter menu?
Like the ir33, the easy / PJEZ splits its parameters into type F (frequent) and type C (configuration, password-protected, default password 22). The set point itself is one press away: hold SET for 1 second, change it with UP/DOWN, press SET.
Type F parameters:
- Hold SET for more than 3 seconds (mute the buzzer first if an alarm is sounding). The display shows PS.
- Use UP and DOWN to scroll the parameters; the LED for the parameter's category lights.
- Press SET to see a value, UP/DOWN to change it, SET to store it temporarily and show the parameter again.
- Hold SET for more than 3 seconds to save permanently and exit.
Type C parameters: at the PS prompt press SET to open the password field, scroll to 22 with UP/DOWN, press SET to confirm, then work through the list exactly as above and hold SET 3 seconds to save. Two traps from the manual: if no button is pressed for 60 seconds, everything you changed is discarded and the old settings come back; and if power is cut before the 3-second SET save, the changes are lost.
Every Carel PJ Easy (PJEZ) code at a glance
| Code | What it means |
|---|---|
| E0 | Probe 1 (control) error |
| E1 | Probe 2 (defrost) error |
| E2 | Probe 3 (condenser) error |
| IA | External alarm |
| dOr | Open door alarm |
| LO | Low temperature alarm |
| HI | High temperature alarm |
| EE | Unit parameter error |
| EF | Operating parameter error |
| Ed | Defrost ended by timeout |
| dF | Defrost running (status, not a fault) |
| cht | Dirty condenser pre-alarm |
| CHt | Dirty condenser alarm |
| EtC | Clock alarm |
| SrC | Maintenance request (easy split only): the maintenance interval set in parameter HMP has passed; cleared by setting HMr = 1 information |
14 codes link to a full section below. The other 1 are listed as the manufacturer's manual gives them. Every row comes from the manual cited at the end of this page.
What does each code mean — and what should you do?
E0 — Probe 1 (control) error
The control/ambient probe has failed or is disconnected. The buzzer and alarm relay activate and the controller can no longer regulate on real air temperature.
What causes it:
- The control/ambient probe has failed or is disconnected — buzzer and alarm relay activate
- Ice buildup or physical damage at the air probe
- Product buried against the sensor
Can staff fix it? The quick checks are: see whether the display shows a plausible temperature, clear product away from the sensor, look for ice or damage, and power-cycle once. A probe that stays failed is a part.
What to check, in order:
- Check whether the display shows a plausible temperature or an error
- Look at the air probe inside the unit for ice buildup or physical damage (visual only)
- Power-cycle the unit once at the breaker or plug
- Move product away from the sensor if it's buried
Why it takes a technician: The controller can no longer regulate on real air temperature — probe testing and replacement is live electrical work, and the box is effectively blind until it's done.
Source: Carel — easy / easy compact / easy split (PJEZ) electronic digital thermostats — user manual (+030220791 rel. 3.4, 28.04.2021)
E1 — Probe 2 (defrost) error
The defrost/evaporator probe has failed or is disconnected. Defrosts will end on time instead of coil temperature.
What causes it:
- The defrost/evaporator probe has failed or is disconnected
- Defrosts now end on time instead of coil temperature — excess coil ice is the symptom to watch
Can staff fix it? Watch the next defrost: does the coil come fully clear? Power-cycle once; if E1 returns, stop. The probe swap is a service call.
What to check, in order:
- Look at the evaporator coil for excess ice
- Watch the next defrost — does the coil come fully clear?
- Power-cycle once; if E1 returns, stop
Why it takes a technician: Replacing the defrost probe means working in the live control circuit, and a coil that never fully clears will ice over and choke the evaporator until the box can't hold temperature.
Source: Carel — easy / easy compact / easy split (PJEZ) electronic digital thermostats — user manual (+030220791 rel. 3.4, 28.04.2021)
E2 — Probe 3 (condenser) error
On PJEZ models with a third probe, the condenser probe has failed or is disconnected, so high-condenser-temperature protection is compromised.
What causes it:
- On PJEZ models with a third probe, the condenser probe has failed or is disconnected
- Damage to the small sensor wire at the condensing unit
- High-condenser-temperature protection is compromised while it's down
Can staff fix it? Look over the sensor wire (look only), clean obvious dust away from the condenser since the unit's own protection is offline, and power-cycle once. That's it for staff.
What to check, in order:
- Visually check the small sensor wire at the condensing unit for damage (look only)
- Clean obvious dust and debris away from the condenser while you're there
- Power-cycle once and see if E2 clears
Why it takes a technician: The probe needs live testing and replacement, and until then nothing is watching for a dust-matted condenser that can't reject heat — the exact condition this probe exists to catch.
Source: Carel — easy / easy compact / easy split (PJEZ) electronic digital thermostats — user manual (+030220791 rel. 3.4, 28.04.2021)
IA — External alarm
The digital input configured as an external alarm (parameter A4, with delay A7) has tripped — an external safety or monitoring contact opened.
What causes it:
- The digital input configured as an external alarm (parameter A4, delay A7) tripped — an external safety or monitoring contact opened
- A stopped condensing unit or tripped breaker
- Condenser airflow blockage tripping an external safety
Can staff fix it? Confirm the condensing unit runs, check the breaker, clear condenser airflow, find out from your installer what's wired to the input, and log occurrences. Diagnosing the device itself isn't DIY.
What to check, in order:
- Check the condensing unit is running and its breaker is on
- Check condenser airflow and clear blockages
- Find out from your installer what device is wired to the digital input
- Log when IA occurs for the service visit
Why it takes a technician: A repeating external alarm means a protective device keeps finding a reason to open — identifying and testing it takes someone who knows the installation, and if it's a pressure safety, certified refrigerant-side diagnosis.
Source: Carel — easy / easy compact / easy split (PJEZ) electronic digital thermostats — user manual (+030220791 rel. 3.4, 28.04.2021)
dOr — Open door alarm
The door switch wired to the digital input reports the door has been open too long. Temperature will rise and the coil will ice faster while it's open.
What causes it:
- The door switch reports the door open too long — open-door time raises temperature and ices the coil faster with humid air
- Something blocking the door, or a torn/iced gasket preventing a seal
- A misaligned door switch that doesn't actuate when the door shuts
Can staff fix it? Usually, yes. Close the door fully, remove obstructions, inspect the gasket, check the switch alignment, and confirm the alarm clears a few minutes after a proper close.
What to check, in order:
- Close the door fully and remove anything blocking it
- Inspect the gasket for tears, gaps, or ice preventing a seal
- Check the door switch alignment and that it actuates when the door shuts
- Confirm the alarm clears after the door has been closed a few minutes
Why it takes a technician: If the alarm stays on with the door verifiably closed, the switch or its wiring is at fault — live circuit testing at the controller.
Source: Carel — easy / easy compact / easy split (PJEZ) electronic digital thermostats — user manual (+030220791 rel. 3.4, 28.04.2021)
LO — Low temperature alarm
Temperature has fallen below the low alarm threshold (AL) for longer than the delay (Ad). Buzzer and alarm relay activate; it clears automatically when temperature recovers.
What causes it:
- Temperature below the AL threshold longer than the Ad delay — buzzer and relay active until it recovers
- A drifting probe giving a false cold reading
- Product stacked against the sensor
- A compressor that never cycles off
Can staff fix it? Verify with an independent thermometer first — a drifting probe is a common false alarm. Clear the sensor and watch whether the compressor ever cycles off. The alarm clears itself when temperature recovers.
What to check, in order:
- Verify with an independent thermometer — rule out a drifting probe
- Make sure product isn't stacked against the sensor
- Watch whether the compressor ever cycles off
Why it takes a technician: A unit genuinely running below setpoint continuously has a control or refrigeration fault that needs live diagnosis — and the cost of waiting is freeze-damaged product.
Source: Carel — easy / easy compact / easy split (PJEZ) electronic digital thermostats — user manual (+030220791 rel. 3.4, 28.04.2021)
HI — High temperature alarm
Temperature has exceeded the high alarm threshold (AH) for longer than the delay (Ad). The most common walk-in alarm; often door- or defrost-related rather than a mechanical failure.
What causes it:
- Door open or gasket not sealing — the most common walk-in alarm is usually door- or defrost-related, not mechanical
- Warm product loaded or heavy door traffic — recovery takes time
- A defrost that just finished
- A dust-blocked condenser coil, dead condenser fan, or tripped breaker
Can staff fix it? Often, yes. Door, gasket, loading, post-defrost recovery, condenser airflow, and the breaker are all staff checks — give the box a couple of hours to recover with the door shut.
What to check, in order:
- Check the door is closed and the gasket seals; look for product blocking it
- Consider recent loading of warm product or heavy door traffic — allow recovery time
- Check whether a defrost just finished
- Check the condensing unit: fan running, coil clear of dust and debris, breaker on
Why it takes a technician: If temperature keeps rising or won't recover in that window, the fault is in the sealed system — gauge diagnosis requiring EPA Section 608 certification, with product warming the whole time.
Source: Carel — easy / easy compact / easy split (PJEZ) electronic digital thermostats — user manual (+030220791 rel. 3.4, 28.04.2021)
EE — Unit parameter error
The controller detected an error in its stored unit parameters (internal memory). Configuration data may be corrupted.
What causes it:
- The controller detected an error in its stored unit parameters — internal memory
- Configuration data possibly corrupted
Can staff fix it? Power-cycle once, press SET for a second to confirm the setpoint still reads what it should, and monitor the box with an independent thermometer. No parameter tinkering.
What to check, in order:
- Power-cycle the controller once
- Check the setpoint still reads what it should (press SET for 1 second)
- Monitor the box with an independent thermometer until resolved
Why it takes a technician: A persistent memory error means the program has to be reloaded or the controller replaced by a tech — until then the box may be running on corrupted settings.
Source: Carel — easy / easy compact / easy split (PJEZ) electronic digital thermostats — user manual (+030220791 rel. 3.4, 28.04.2021)
EF — Operating parameter error
Error in the controller's stored operating parameters (working settings and setpoints). Settings may have reverted or corrupted.
What causes it:
- An error in the stored operating parameters — working settings and setpoints
- Settings may have reverted or corrupted
Can staff fix it? Power-cycle once, compare the setpoint against what's posted for the unit, and watch box temperature independently. If EF returns or settings look wrong, stop there.
What to check, in order:
- Power-cycle once and check whether EF clears
- Verify the setpoint and compare against what's posted for the unit
- Watch box temperature independently in the meantime
Why it takes a technician: The parameter set needs reloading from records by someone who has them — running on reverted setpoints can quietly hold the box at the wrong temperature in either direction.
Source: Carel — easy / easy compact / easy split (PJEZ) electronic digital thermostats — user manual (+030220791 rel. 3.4, 28.04.2021)
Ed — Defrost ended by timeout
The defrost ended because it hit the maximum duration (dP) rather than reaching the end-defrost temperature (dt). Usually means more ice on the coil than the defrost can clear.
What causes it:
- The defrost hit its maximum duration (dP) before reaching the end-defrost temperature (dt) — more ice on the coil than the defrost can clear
- Humid-air leaks at the door gasket icing the coil between defrosts
- Ice or overflow in the drain pan
- A weak defrost heater, bad probe, or undersized defrost schedule
Can staff fix it? The diagnosis help is: look at the coil right after a defrost — remaining ice confirms it — check the door gasket, eyeball the drain pan, and note whether Ed shows after every defrost.
What to check, in order:
- Look at the evaporator coil right after a defrost — remaining ice confirms the problem
- Check the door gasket and closure for humid-air leaks
- Check the drain pan for ice or overflow (visual only)
- Note whether Ed shows after every defrost
Why it takes a technician: A repeating Ed means the defrost heater, probe, or schedule needs service — heater testing is live electrical work — and an uncorrected coil eventually blocks solid and stops the box cooling.
Source: Carel — easy / easy compact / easy split (PJEZ) electronic digital thermostats — user manual (+030220791 rel. 3.4, 28.04.2021)
dF — Defrost running (status, not a fault)
dF flashes on the display while a defrost is in progress (when parameter d6 = 0). This is normal operation, not an error code.
What causes it:
- A defrost is in progress and the display flashes dF (when parameter d6 = 0) — normal operation, not an error
- During defrost the fans may be off and the box may warm slightly — also normal
Can staff fix it? Yes — wait it out and avoid opening the door during defrost. Only if dF never clears well beyond the normal defrost time should it be treated as a fault.
What to check, in order:
- Wait for the defrost to finish; fans may be off and the box may warm slightly — normal
- Avoid opening the door during defrost
- If dF never clears well beyond the normal defrost time, treat it as a fault
Why it takes a technician: A unit that appears stuck in defrost, or won't pull back down afterward, has a defrost termination or control fault — probe and heater diagnosis is a live-electrical service job.
Source: Carel — easy / easy compact / easy split (PJEZ) electronic digital thermostats — user manual (+030220791 rel. 3.4, 28.04.2021)
cht — Dirty condenser pre-alarm
Condenser temperature has passed the pre-alarm level — an early warning that the condenser coil is dirty or starved of airflow.
What causes it:
- Condenser temperature past the pre-alarm level — an early warning the coil is dirty or starved of airflow
- Dust, lint, or grease blocking the fins so the coil can't reject heat
- Items stored against or on top of the condensing unit
- A condenser fan not running with the compressor
Can staff fix it? Yes — this warning exists so staff can act before it escalates. Clear the airflow, check the fan, and get the dirt off the coil while it's still a pre-alarm.
What to check, in order:
- Look at the condenser coil for dust, lint, or grease blocking the fins
- Remove anything stored against or on top of the condensing unit
- Confirm the condenser fan runs with the compressor
Why it takes a technician: If it keeps returning after the airflow is cleared, the coil needs a professional cleaning — a condenser running hot is quietly loading the compressor every hour it runs.
Source: Carel — easy / easy compact / easy split (PJEZ) electronic digital thermostats — user manual (+030220791 rel. 3.4, 28.04.2021)
CHt — Dirty condenser alarm
Condenser temperature has exceeded the alarm threshold (parameter Ac) — the escalated version of cht, with buzzer and alarm relay active. Continued running risks safety trips and compressor stress.
What causes it:
- Condenser temperature over the Ac alarm threshold — the escalated version of cht, with buzzer and alarm relay active
- A stopped condenser fan
- A heavily matted coil or blocked airflow that the pre-alarm stage didn't get fixed
Can staff fix it? Check the fan and clear visible blockages, but don't keep silencing the alarm to force operation — that's how a dirty-coil warning turns into a dead compressor.
What to check, in order:
- Check the condenser fan is turning
- Clear all visible blockages and check for a heavily matted coil
- Don't keep silencing the alarm to force operation
Why it takes a technician: Continued running against a hard high-condenser alarm risks safety trips and compressor damage — a tech needs to clean the coil properly and verify the unit before it's trusted again.
Source: Carel — easy / easy compact / easy split (PJEZ) electronic digital thermostats — user manual (+030220791 rel. 3.4, 28.04.2021)
EtC — Clock alarm
On PJEZ models with a real-time clock, the clock has failed or lost its setting, so time-of-day defrost bands won't run correctly.
What causes it:
- On PJEZ models with a real-time clock, the clock failed or lost its setting — often after a power outage
- Time-of-day defrost bands won't run correctly until it's reset
Can staff fix it? Sometimes. After an outage, a trained operator re-setting the clock parameters may resolve it. Verify scheduled defrosts still occur at their normal times.
What to check, in order:
- Check for a recent power outage
- Verify scheduled defrosts are still occurring at normal times
- Have your trained operator re-set the clock parameters if applicable
Why it takes a technician: A clock that won't hold time points to failed hardware — the controller may need replacement, and until then the defrost schedule the box depends on isn't running when it should.
Source: Carel — easy / easy compact / easy split (PJEZ) electronic digital thermostats — user manual (+030220791 rel. 3.4, 28.04.2021)
How do you diagnose a Carel PJ Easy (PJEZ) alarm, step by step?
- Note the code and the real temperature. Read the box on a separate thermometer before you change anything.
- Mute, don't clear. SET silences the buzzer; the code and relay stay on until the cause is fixed.
- E0, E1, E2 are probe 1 (control), probe 2 (defrost) and probe 3 (condenser/product). PJ Easy and easy compact models take Carel NTC probes (10 kΩ at 25 °C) or PTC probes (985 Ω at 25 °C), depending on the model's order code; easy split models use NTC or high-temperature NTC probes (50 kΩ). A replacement probe must match what the controller is set up for. Thermistor probes have no polarity.
- dOr is the door switch. If the pre-alarm times A7 and d8 are both zero the alarm is immediate. It resets when the door is closed, or when the controller is switched off with UP for 3 seconds.
- Ed means a defrost ended on time, not temperature. It clears after the next defrost that ends correctly — look at the coil for ice before then.
- cht, then CHt. cht is the dirty-condenser pre-alarm; CHt is the full alarm and the only one that needs a manual reset. Clean the condenser coil with the power off, then reset.
- EtC clears by setting the time. EE/EF are parameter-memory errors — a technician job if a power cycle doesn't clear them.
Which parts are usually involved?
| Part | Codes that point to it | Note |
|---|---|---|
| Probe 1 — control / room probe (NTC or PTC) | E0, HI, LO | |
| Probe 2 — defrost probe on the evaporator | E1, Ed | |
| Probe 3 — condenser or product probe | E2, cht, CHt | |
| Condenser coil and fan | cht, CHt | |
| Door switch | dOr | |
| Device on the multifunction input | IA | |
| Defrost heater and defrost termination | Ed, dF | |
| The controller (parameter memory, clock) | EE, EF, EtC |
What refrigeration is behind these codes?
Every code here is the controller reporting a reading from the refrigeration system. The background is explained once, for every controller on this site: how a controller holds temperature — and how its sensors are tested; how defrost works and what goes wrong; why the condenser matters.
If it does come to a service call and you're in Nashville, TN or Birmingham, AL, we maintain independently compiled lists of local companies that service walk-in coolers — real businesses with verified contact information, none of whom paid to be listed.