What do Dixell (Emerson) XR06CX and XR60CX alarm codes mean?
Short answer: Dixell's XR controllers flash a short message on the display. P-codes are probe failures, HA/LA are high and low temperature alarms, HA2/LA2 are condenser temperature alarms (XR60CX with a condenser probe), dA is the door, EA an external alarm, and CA is the serious one — a critical input that switches every output off. OF (XR06CX) or PoF (XR60CX) just means the keypad is locked.
Which machines use it?
Dixell's XR series (now under Emerson/Copeland) is probably the most widely installed walk-in thermostat family there is. The small panel-mount XR06CX and XR60CX ship as the standard controller on boxes from Norlake, Kolpak, and many other walk-in manufacturers, and they're a favorite replacement control when an original thermostat dies. The display normally shows box temperature; when something's wrong, a short two- or three-character code flashes or alternates with the temperature — P-codes for failed probes, HA/LA for temperature alarms, dA for the door, CA for a shutdown-level fault. Practical tip: most alarms silence when you press any key but keep displaying until the condition clears — so a code still showing means the problem is still live.
These codes are specific to the Dixell XR60CX, the bigger sibling in the XR series (Emerson/Copeland) with defrost, fan control, and support for up to four probes. Like the rest of the XR family it ships on walk-in boxes from Norlake, Kolpak, and many other manufacturers, and is a common field replacement controller. The extra probes are what create these codes: P3 and P4 flag the optional third and fourth probes, while HA2 and LA2 are condenser-temperature alarms that only exist when a condenser probe is fitted. Refrigeration usually continues while these show. Practical tip: HA2 is the controller telling you the condenser is running hot — nine times out of ten that's a dirty coil or blocked airflow you can see with your own eyes.
How do you read and clear the display?
How each alarm recovers is fixed by the manual. Probe alarms start a few seconds after a probe fails and stop a few seconds after it reads normally again. HA, LA, HA2 and LA2 stop as soon as the temperature is back to normal. EA and CA (serious-alarm mode) recover as soon as the digital input is released — but CA in pressure-switch mode (XR60CX) only recovers by switching the controller off and on. To unlock the keypad, hold the up and down keys together for more than 3 seconds until on (XR06CX) or Pon (XR60CX) appears.
How do you enter the parameter menu?
Dixell XR controllers keep two parameter levels: Pr1, the user level, and Pr2, the hidden menu that holds every parameter in the instrument (the XR06CX manual labels the same two levels L1 and L2). Both manuals give the same key procedure; the XR60CX manual names the keys explicitly as SET plus the DOWN arrow.
Set point: hold SET for more than 2 seconds, change it with the arrows, press SET.
Programming mode (Pr1):
- Hold SET and DOWN together for 3 seconds; the °C or °F LED starts blinking.
- Select a parameter with the arrows and press SET to show its value.
- Change it with UP/DOWN, then press SET to store it and move to the next parameter.
- Exit with SET + UP, or wait 15 seconds without pressing a key. Note the manual's warning: a value is stored even if you leave by letting the time-out expire.
Hidden menu (Pr2): enter programming mode as above, release the keys, then hold SET + DOWN again for more than 7 seconds. The display shows Pr2 (or L2) followed by the first parameter, Hy. If nothing is in the user level, noP shows after 3 seconds — keep holding until Pr2 appears. Any parameter can be moved between the hidden menu and the user level with SET + DOWN while it is displayed; a parameter that is also in Pr1 shows a decimal point.
Keypad lock: hold UP + DOWN for more than 3 seconds; POF shows and only the set point and max/min temperatures can be viewed. The same hold unlocks it (Pon on the XR60CX, on on the XR06CX).
Every Dixell XR06CX / XR60CX code at a glance
| Code | What it means | Applies to | What the controller does |
|---|---|---|---|
| P1 | Room (thermostat) probe failure | XR06CX & XR60CX | Compressor runs on a timer (Cy/Cn; Con/COF on XR60CX) |
| P2 | Evaporator (defrost) probe failure | XR06CX & XR60CX | Defrost ends on time |
| HA | Maximum (high) temperature alarm | XR06CX & XR60CX | Outputs unchanged |
| LA | Minimum (low) temperature alarm | XR06CX & XR60CX | Outputs unchanged |
| dA | Door open alarm | XR06CX & XR60CX | Compressor and fans restart |
| EA | External alarm | XR06CX & XR60CX | Outputs unchanged |
| CA | Serious external alarm / pressure switch alarm — all outputs off | XR06CX & XR60CX | All outputs off |
| OF / PoF | Keyboard locked (not a fault) | XR06CX & XR60CX | — |
| P3 | Third probe failure | XR60CX only | Outputs unchanged |
| P4 | Fourth probe failure | XR60CX only | Outputs unchanged |
| HA2 | Condenser high temperature alarm | XR60CX only | Depends on parameter Ac2 |
| LA2 | Condenser low temperature alarm | XR60CX only | Depends on parameter bLL |
| on / Pon | Keypad unlocked message | XR06CX & XR60CX | — |
| noA | No alarm recorded message | XR60CX only | — |
| noP | The selected probe is not enabled (in programming mode: no parameter present in Pr1) message | XR60CX only | — |
12 codes link to a full section below. The other 3 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?
P1 — Room (thermostat) probe failure
Applies to: XR06CX & XR60CX
The room air temperature probe has failed open or shorted. The controller falls back to timed compressor cycling using the Cy/Cn (COn/COF) parameters, so the box keeps running on a timer instead of actual temperature. The alarm clears automatically a few seconds after the probe reads normally again.
What causes it:
- The room air probe failed open or shorted
- A probe or wire damaged, wet, or iced over inside the box
- A transient fault — the alarm clears itself seconds after the probe reads normally again
Can staff fix it? Partially. The controller has already protected the box by cycling the compressor on a timer, so cooling continues. Staff can verify box temperature with a separate thermometer, look for obvious probe damage, and power-cycle once.
What to check, in order:
- Record the alarm and check box temperature with a separate thermometer
- Look inside the box for a damaged, wet, or iced-over probe and wire
- Power-cycle the unit at the breaker once to rule out a transient fault
Why it takes a technician: The manual specifically says check the probe connections before replacing the probe — meter work at the controller terminals. Timed fallback cycling holds the box roughly, not precisely, so don't leave it that way for weeks.
Source: Dixell (Copeland) — XR06CX digital controller with defrost and fans management — manual (1592020160 XR06CX GB r1.2, 27.07.2015)
P2 — Evaporator (defrost) probe failure
Applies to: XR06CX & XR60CX
The evaporator coil probe has failed, so defrost cycles now end on time instead of coil temperature. Cooling continues, but the coil can ice up if defrosts terminate improperly. Clears automatically when the probe reads normally.
What causes it:
- The evaporator coil probe failed, so defrosts now end on time instead of coil temperature
- Improperly terminated defrosts letting the coil ice up
- A visibly damaged probe wire at the evaporator
Can staff fix it? No real fix on-site. Staff can check the coil for ice, look for obvious wire damage, and watch box temperature until the probe is replaced — cooling does continue meanwhile.
What to check, in order:
- Check the evaporator coil for ice buildup
- Look for a visibly damaged probe wire at the evaporator
- Monitor box temperature until the probe is replaced
Why it takes a technician: Checking connections and replacing the evaporator probe is technician work, and it gets urgent the moment ice starts building on the coil, because an iced coil eventually stops cooling the box.
Source: Dixell (Copeland) — XR06CX digital controller with defrost and fans management — manual (1592020160 XR06CX GB r1.2, 27.07.2015)
HA — Maximum (high) temperature alarm
Applies to: XR06CX & XR60CX
Room temperature reached the maximum temperature alarm setpoint (AU/ALU parameter) and stayed there past the alarm delay. Outputs are unchanged — the unit keeps trying to cool — and the alarm stops automatically once temperature returns to normal.
What causes it:
- Door not fully closed or gasket not sealing
- Ice on the evaporator coil or fans not moving air
- Condensing unit off, tripped breaker, or a dirty condenser coil with blocked airflow
- Warm product loaded before the box recovered
Can staff fix it? Often. The unit keeps trying to cool (outputs are unchanged) and the alarm silences itself once temperature recovers — so working the door/coil/condenser checklist is genuinely the fix in most cases.
What to check, in order:
- Make sure the door is fully closed and the gasket is sealing
- Check the evaporator coil for visible ice and the fans for movement
- Check the condensing unit: is it running, and is its coil clean with clear airflow?
- Verify the breaker for the condensing unit hasn't tripped
- Avoid loading warm product until temperature recovers
Why it takes a technician: If temperature isn't dropping within an hour of closing the door and clearing airflow, what remains is refrigerant-side — low charge, a failing compressor — which is gauge work requiring EPA Section 608 certification, with product warming as you wait.
Source: Dixell (Copeland) — XR06CX digital controller with defrost and fans management — manual (1592020160 XR06CX GB r1.2, 27.07.2015)
LA — Minimum (low) temperature alarm
Applies to: XR06CX & XR60CX
Room temperature dropped to the minimum temperature alarm setpoint (AL/ALL parameter) past the alarm delay. Outputs are unchanged, and the alarm stops automatically when temperature returns to normal.
What causes it:
- Setpoint recently changed lower than intended
- A stuck contactor or control problem keeping the compressor running past setpoint
- Freeze-sensitive product parked in the evaporator discharge air
Can staff fix it? Partially. Verify actual temperature with a separate thermometer, check the setpoint, and move freeze-sensitive product away from the discharge air. The alarm clears itself when temperature normalizes.
What to check, in order:
- Verify actual box temperature with a separate thermometer
- Check whether the setpoint was recently changed
- Move freeze-sensitive product away from the evaporator discharge if the box is overcooling
Why it takes a technician: A box that keeps running colder than setpoint points at a stuck contactor or control fault — live electrical diagnosis. In a cooler, every extra hour of overcooling is frozen, ruined product.
Source: Dixell (Copeland) — XR06CX digital controller with defrost and fans management — manual (1592020160 XR06CX GB r1.2, 27.07.2015)
dA — Door open alarm
Applies to: XR06CX & XR60CX
The door switch input shows the door has been open longer than the digital-input delay (di/did parameter). Depending on configuration, the compressor and/or fans may have been stopped while the door is open; they restart per the rd/rrd setting. The alarm stops as soon as the door switch closes.
What causes it:
- Door open longer than the digital-input delay
- A sagging door or damaged gasket/hinges holding the switch open
- The plunger or magnetic door switch stuck, iced, or knocked out of alignment
Can staff fix it? Usually. Close and latch the door, check gasket and hinges, and free or realign a stuck or iced switch — the alarm stops the moment the switch closes. Note the compressor and fans may have been paused while the door read open.
What to check, in order:
- Close the door fully and confirm it latches
- Check the door gasket and hinges — a sagging door can hold the switch open
- Check that the door switch (usually a plunger or magnetic switch) isn't stuck, iced, or knocked out of alignment
Why it takes a technician: If dA stays on with the door verifiably closed, the switch or its wiring has failed and needs testing and replacement — a quick technician visit, but meter work all the same.
Source: Dixell (Copeland) — XR06CX digital controller with defrost and fans management — manual (1592020160 XR06CX GB r1.2, 27.07.2015)
EA — External alarm
Applies to: XR06CX & XR60CX
A device wired to the digital input (configured as external alarm, iF/i1F=EA/EAL) has tripped. Refrigeration outputs do not change, and the alarm stops when the external device resets.
What causes it:
- Whatever device the installer wired to the digital input has tripped — commonly a condensate overflow switch or a high-pressure switch indicator
- Refrigeration outputs are unchanged; the controller is only relaying the signal
- Clears when the external device resets
Can staff fix it? Depends entirely on what's wired in, which varies by installer. Staff can check the obvious suspects — condensate overflow, pressure switch indicator — and confirm cooling is still normal.
What to check, in order:
- Identify what device is wired to the alarm input on your unit (varies by installer)
- Check the obvious suspects: condensate overflow switch, high-pressure switch indicator
- Note when the alarm started and whether cooling is still normal
Why it takes a technician: If nobody on site can identify or reset the device behind the alarm, a technician has to trace the input wiring. An EA that keeps returning means the external device keeps finding a real problem.
Source: Dixell (Copeland) — XR06CX digital controller with defrost and fans management — manual (1592020160 XR06CX GB r1.2, 27.07.2015)
CA — Serious external alarm / pressure switch alarm — all outputs off
Applies to: XR06CX & XR60CX
A digital input configured as serious alarm (bA/bAL) or pressure switch alarm (PAL on XR60CX) has tripped, and the controller has switched ALL outputs off — refrigeration is stopped. A serious-alarm CA clears when the input resets; a pressure-switch CA (after the set number of trips) recovers only by switching the instrument off and on.
What causes it:
- A digital input configured as serious alarm has tripped and the controller switched ALL outputs off
- On the XR60CX, the pressure switch alarm reached its set number of trips — that variant only recovers via a power off/on
- Blocked condenser airflow or a tripped breaker upstream of the pressure switch
Can staff fix it? No — and it's urgent, because refrigeration is stopped. Staff can check for obvious condenser blockage or a tripped breaker and move product if help is far off. Do not keep resetting power to force it to run.
What to check, in order:
- Treat this as urgent: the system is off and box temperature will rise
- Check the condensing unit for obvious issues — blocked condenser airflow, tripped breaker
- Move product if a tech cannot arrive quickly
- Do not repeatedly reset power to force it to run
Why it takes a technician: Repeated pressure-switch trips are the system reporting a real refrigeration-side fault; forcing restarts just hammers the compressor. Diagnosis needs gauges and EPA Section 608 certification, and with all outputs off, product loss is on the clock.
Source: Dixell (Copeland) — XR60CX digital controller with defrost and fans management — manual (1592020060 XR60CX GB r1.1, 27.04.2015)
OF / PoF — Keyboard locked (not a fault)
Applies to: XR06CX & XR60CX
"OF" (XR06CX) or "PoF" (XR60CX) appears when a key is pressed while the keypad is locked. It is not an alarm — the lock prevents accidental setpoint changes. Unlock by holding the UP and DOWN arrow keys together for more than 3 seconds until "on"/"Pon" is displayed.
What causes it:
- The keypad is locked and someone pressed a key — this is a status message, not a fault
- The lock exists precisely to stop accidental setpoint changes
Can staff fix it? Completely. Hold the UP and DOWN arrows together for more than 3 seconds until the display shows "on" (XR06CX) or "Pon" (XR60CX) — unlocked. Nothing about refrigeration has changed.
What to check, in order:
- Hold the UP and DOWN arrow keys together for over 3 seconds to unlock
- The display shows "on" (XR06CX) or "Pon" (XR60CX) when unlocked
Why it takes a technician: The only scenario needing service is a keypad that refuses to unlock after the correct hold, which points to a failed keypad or controller.
Source: Dixell (Copeland) — XR60CX digital controller with defrost and fans management — manual (1592020060 XR60CX GB r1.1, 27.04.2015)
P3 — Third probe failure
Applies to: XR60CX only
The optional third probe (often used for condenser temperature monitoring on the XR60CX) has failed. Refrigeration outputs are unchanged; the alarm clears automatically when the probe reads normally again.
What causes it:
- The optional third probe — often used for condenser temperature monitoring — failed
- Refrigeration outputs unchanged; the box should still be cooling normally
- Auto-clears when the probe reads normally again
Can staff fix it? Nothing needs fixing today: cooling is unaffected. Verify box temperature with a separate thermometer and report the code to your service company.
What to check, in order:
- Note the alarm; the box should still be cooling normally
- Verify box temperature with a separate thermometer
- Report the code to your service company
Why it takes a technician: The probe connection needs checking and the probe replacing at the next service visit — while it's out, the controller has lost its condenser high-temperature protection (HA2), which is worth restoring before summer.
Source: Dixell (Copeland) — XR60CX digital controller with defrost and fans management — manual (1592020060 XR60CX GB r1.1, 27.04.2015)
P4 — Fourth probe failure
Applies to: XR60CX only
The optional fourth probe (connected via the Hot Key plug on the XR60CX) has failed. Outputs are unchanged and the alarm auto-clears when the probe recovers.
What causes it:
- The optional fourth probe (connected via the Hot Key plug) failed
- Outputs unchanged, cooling continues, and the alarm auto-clears if the probe recovers
Can staff fix it? Nothing urgent — cooling continues normally. Verify box temperature with a separate thermometer and log the code.
What to check, in order:
- Note the alarm; cooling continues normally
- Verify box temperature with a separate thermometer
Why it takes a technician: A technician checks the Hot Key probe connection and replaces the probe at the next scheduled visit; this is a monitoring loss, not a refrigeration fault.
Source: Dixell (Copeland) — XR60CX digital controller with defrost and fans management — manual (1592020060 XR60CX GB r1.1, 27.04.2015)
HA2 — Condenser high temperature alarm
Applies to: XR60CX only
The condenser probe reads above the Au2 high-limit. Depending on the AC2 parameter the compressor may be switched off to protect it. High condenser temperature usually means a dirty condenser coil, blocked airflow, or a failed condenser fan.
What causes it:
- Dirty condenser coil — dust, lint, or kitchen grease insulating it
- Stored boxes or debris blocking airflow around the condensing unit
- A failed condenser fan
- Refrigerant-side problems driving head pressure up — the non-DIY tail of the list
Can staff fix it? Frequently, yes — this is the most staff-fixable alarm on the controller. With the disconnect off, brush or vacuum the coil (never pressure-wash into the fins), clear the stored junk, and confirm the fan spins. Note the compressor may have been switched off to protect itself.
What to check, in order:
- With the unit's disconnect off, look at the condenser coil for dust, lint, or grease buildup
- Clear anything stored around the condensing unit blocking airflow
- Gently brush or vacuum the coil surface (no pressure washing toward the fins)
- Confirm the condenser fan spins when the unit runs
Why it takes a technician: If HA2 returns after a genuinely clean coil and free airflow, high head pressure is coming from the refrigerant side — overcharge, non-condensables — and that diagnosis takes gauges and EPA Section 608 certification.
Source: Dixell (Copeland) — XR60CX digital controller with defrost and fans management — manual (1592020060 XR60CX GB r1.1, 27.04.2015)
LA2 — Condenser low temperature alarm
Applies to: XR60CX only
The condenser probe reads below the AL2 low-limit. Depending on the bLL parameter the compressor may be switched off while the alarm is present. Often seen with very low ambient temperatures at the condensing unit.
What causes it:
- Very low ambient temperature at the condensing unit — the usual winter cause
- Head-pressure (low-ambient) controls not doing their job
- Depending on the bLL parameter, the compressor may be off while the alarm is active
Can staff fix it? Not really. Note the outdoor temperature and whether the unit is still cooling — that's the useful staff contribution.
What to check, in order:
- Note outdoor/ambient temperature at the condensing unit
- Record the alarm and whether the unit is still cooling
Why it takes a technician: Low-ambient operation depends on head-pressure controls (fan cycling, flooding valves) that a technician checks with gauges. If the compressor is being held off in cold weather, the box can still drift warm — don't ignore it because it's winter.
Source: Dixell (Copeland) — XR60CX digital controller with defrost and fans management — manual (1592020060 XR60CX GB r1.1, 27.04.2015)
How do you diagnose a Dixell XR06CX / XR60CX alarm, step by step?
- Note the message and the actual box temperature. A probe alarm means the display itself can't be trusted.
- P1 means the box is cooling on a timer. With the room probe failed, the compressor runs by time — on for Cy minutes, off for Cn (Con/COF on the XR60CX). With Cy at 0 the compressor stays off; with Cn at 0 it runs continuously. Check what yours is set to before assuming the box is safe.
- P2 means defrost ends on time. With the evaporator probe failed, defrost stops at the maximum length (Md) instead of on temperature — so the coil can come out of defrost with ice left on it, or stay in defrost longer than it needs to.
- Check connections before replacing a probe — Dixell's own instruction. Probes are NTC (XR06CX: up to two; XR60CX: up to four, NTC or PTC). The read-only parameters d1 and d2 (XR06CX) show what the thermostat and evaporator probes are reading.
- Probe placement matters. Mount probes bulb-up so liquid can't get in; keep the thermostat probe out of air streams; put the defrost-termination probe among the evaporator fins in the coldest spot, where most ice forms and away from heaters — otherwise defrosts end early.
- dA: with the door open, HA and LA are disabled. The door alarm comes on after the delay set in parameter di, and what the compressor and fans do while the door is open is set by parameter dC.
- CA: find what's on the digital input. In serious-alarm mode (i1F = bAL) or pressure-switch mode (i1F = PAL) every output goes off. A tripped pressure switch is a refrigeration problem for a technician.
Which parts are usually involved?
| Part | Codes that point to it | Note |
|---|---|---|
| Thermostat (room) probe P1 — NTC | P1, HA, LA | |
| Evaporator (defrost) probe P2 | P2 | |
| Third and fourth probes (XR60CX) | P3, P4, HA2, LA2 | |
| Condenser coil (with a condenser probe fitted) | HA2 | |
| Door switch on the digital input | dA | |
| External alarm device or pressure switch on the digital input | EA, CA | |
| Defrost heater and termination | P2 |
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.