In short: Icing is a symptom, not a cause. Persistent icing is usually down to moisture getting in, a wrong defrost setting or a fault. Melting the ice without finding the cause only puts the problem off for a few days.
Why does icing matter?
When the gaps between the evaporator fins fill with ice, the air pushed by the fan can't pass through the coil. The room can't reach setpoint, the compressor runs non-stop and product temperature fluctuates. In the long run this raises both energy use and the risk of product loss.
The 5 most common causes
01
Door gaskets and door habitsWarm, moist air coming through a door left open or with a damaged gasket turns into ice on the evaporator. Ice around the door and a sudden rise in room humidity are typical signs. Checking the gaskets, a door-open alarm and strip curtains are the first steps.
02
Wrong defrost settingIf defrost is too infrequent or too short, ice builds up. A termination sensor in the wrong position also makes defrost end too early. Defrost interval and termination temperature should be set to match how the room is used.
03
Defrost heater or drain faultA burnt-out heater or a frozen drain line makes the melted water freeze again. Heater resistance should be measured and the drain line heater checked.
04
Fan failure or blocked airflowA fan motor that has stopped, or product stacked in front of the evaporator, cuts off the airflow. Fans should be checked regularly and stacking rules made clear.
05
Low refrigerant charge or expansion valve problemWhen the charge drops or the expansion valve misbehaves, icing concentrates on only part of the coil. Superheat measurement, a leak check and valve adjustment are needed.
How can you spot icing early?
Icing doesn't happen all at once; it leaves traces in the data days in advance:
- Defrost takes longer: In the same room, defrost takes a little longer to finish every day.
- The room recovers slowly after defrost: It takes longer to get back to setpoint.
- Compressor duty cycle goes up: The system runs more for the same heat load.
Smart monitoring tracks these three signals continuously. When the trend starts to deteriorate, our team steps in before an alarm is raised, so icing is solved before it turns into product loss.
Having icing problems in your cold rooms?Let's look at the system and find the real cause; if needed, we'll reset the defrost and control settings.