Industrial Chiller Fault and Alarm Codes

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A chiller alarm code tells you what the controller has detected, not what has failed. The same fault can show a different code on every make, because the code comes from the controller, not the chiller.

This library covers the controllers our engineers meet most often on UK industrial sites, in plain English rather than manual-speak.

Quick answer

Chiller alarm codes are generated by the unit’s controller, so the same code means different things on different machines. Find the controller make and model first, usually printed on the front of the display or inside the panel door, then look up the code for that controller. If the chiller trips again after one reset, leave it off and call an engineer: repeated resets on a pressure or compressor fault can cause real damage.

Find Your Controller, Not Your Chiller Badge

Alarm codes come from the controller inside the chiller, not from the manufacturer whose name is on the cabinet. One controller is fitted by many different manufacturers, and manufacturers change controller between model years, between sizes within a range, and sometimes between batches. Two chillers of the same make bought two years apart can show completely different codes.

So the reliable route is the controller, which is why these guides are organised that way.

Not Sure Which Controller You Have?

Send us a photo and we will identify it for you.

Take a picture of the controller display and the data plate on the unit, then email it to info@evolution-cooling.com or call us on 0121 820 8946. We will tell you which controller it is, what the code means and whether it needs an engineer. No charge for that.

To identify it yourself: look at the front of the display, where Dixell iCHILL controllers are marked IC100CX, IC121CX, IC200CX or IC208CX, and others carry a Carel, Eliwell or manufacturer badge. The label on the back of the controller, the manual, or the electrical drawing will also tell you.

Alarm Code Guides by Controller

  • Dixell iCHILL (IC100CX, IC121CX, IC200CX, IC208CX): codes such as AEFL, b1HP and C1tr. Fitted to the MTA iC range, CF Chillers and others.
  • MTA TAEevo (IC121C): the A-code series, A01, A02, A07, A08 and the rest. Fitted across the TAEevo range, including units badged ICS.
  • Climaveneta W3000: numbered codes such as 003, 211 and 261. Fitted to Climaveneta and Mitsubishi Electric chillers.
  • Carel µC²SE: codes such as HP1, LP1, A1, FL and the EVD driver alarms. Fitted to Galletti, some MTA TAEevo variants and many other makes.
  • Eliwell SMP55: codes Er01 to Er19, covering flow, pressure, compressor, pump, antifreeze, tank level and filter alarms, plus how to reset the flow alarm yourself.
  • Carrier Pro-Dialog Plus: numbered codes 1 to 84 plus the CPM compressor codes 01 to 17. Fitted to Carrier 30GX and 30HXC screw chillers.

More guides are being added as we work through the controllers we service most.

Before You Reset Anything

  • Write the code down, and photograph the display. Codes clear when the fault resets, and the code is the fastest route to a diagnosis.
  • Check the alarm log if the controller has one. A fault that has tripped repeatedly is a different problem from one that has tripped once.
  • One reset is reasonable. If it trips again, leave it off. Repeated resets on high-pressure, low-pressure or compressor faults are a common way to turn a repairable fault into a compressor replacement.
  • Never reset an alarm to get a machine through a shift if it is tripping on a safety device. The safety device is doing its job.
  • Refrigerant work is F-Gas regulated. Pressure faults usually need a certified engineer, not a reset.

Common Faults Behind the Codes

Whatever the controller calls them, most chiller alarms come down to a handful of causes:

  • Flow: blocked strainers, failing pumps, air in the circuit, closed valves, or glycol that has thickened in cold weather. See chiller flow issues.
  • High pressure: dirty or blocked condensers, failed fans, high ambient temperature, or overcharge. See high vs low pressure faults.
  • Low pressure: refrigerant loss, expansion valve or solenoid faults, icing, or low flow. See low-pressure problems.
  • Antifreeze: fluid approaching freezing at the evaporator, often flow or glycol related. See our glycol concentration guide.
  • Electrical and sensor: phase loss, contactor failure, probe faults and parameters altered on site.

Code You Cannot Find, or a Chiller That Will Not Run?

Send us a photo of the controller display and the data plate. Our engineers see these machines every day and can usually tell you what it means, and whether it needs an engineer, before anyone travels.

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