What Are The Causes Of Ice Buildup In A Walk-In Cooler?

Frost buildup inside a walk-in cooler can directly affect its performance and, if not fixed soon, it can result in damage to the vital components. So, you need a commercial appliances repair expert to inspect your walk-in cooler and determine why it’s freezing up. Here are some causes of ice buildup in walk-in coolers that will help you fix yours.

Causes Of Your Walk-In Cooler Freezing Up

Human Error

A common reason for walk-in coolers freezing up is the door is left open for too long. Why is this a problem? One of the things that triggers ice buildup inside a walk-in cooler is warm, humid air. When humid air enters the walk-in cooler, the refrigerator works harder to cool down the interior. In this attempt, the humid air turns to ice.

So, if the door of the walk-in cooler is open even for only 10 minutes, it will cause ice buildup. However, this does depend on the region where your facility is. If the air in your region is humid, icing will occur with only a few minutes of the door left open.

Usually, staff members follow the rules and keep the door closed and when they open it, they do it for a very short interval. However, during stocking the refrigerator, staff members might forget to keep the door closed or have to keep it open to bring many batches of food items inside the refrigerator.

So, instruct your staff to keep the door closed when stocking the food and bring all the food inside the walk-in cooler at once and then place it on shelves after that.

Moreover, to prevent the staff from leaving the refrigerator door open accidentally, install self-closing hinges or a door closer. Additionally, to keep the door from being open for too long in normal operations other than food stocking, instruct the employees to be sure of the items they need to take from the refrigerator or put inside it so they take less time when opening the refrigerator and performing the task.

Damaged Gasket

A walk-in cooler has gaskets in different places to keep two separate parts sealed. For example, the door has a gasket installed all over its ends so that when the door is closed, the gasket ensures that warm air doesn’t go inside or cold air doesn’t escape from the refrigerator.

Over time, these gaskets become loose, worn, or damaged. Due to this, even when the door is closed, the worn gasket doesn’t create a perfect seal. Warm, humid air keeps entering the walk-in cooler. This air turns into ice in any part of the interior and causes problems.

Faulty Door Mechanism

Gaskets wear with time, but sometimes, the door mechanism may be the culprit of ice buildup inside your commercial walk-in cooler. In some cases, the hinges become misaligned with time and allow some space that proves to be an entering point for warm air.

To check if the hinges are the cause of the problem, look for spaces near the top and bottom of the door.

Aging Or Damaged Insulation Panels

The inside walls of a walk-in cooler are covered with insulation panels. They keep the refrigerator cold by acting as a shield between the warm air outside and the cold air inside. These are sturdy panels, but they are not immune to damage and general wear and tear.

As these panels age more than 10 years, they start losing their insulation properties. This means they can’t keep the warm air outside as effectively as they did before. So, warm air keeps entering the walk-in cooler and turning into ice.

Moreover, due to improper maintenance or carelessness, these panels can be damaged during cleaning, stocking food items, or removing items. This also makes them considerably ineffective.

So, whenever, there is an ice buildup issue, have the insulation panels checked as well. Take note that when the insulation panels of your walk-in cooler are worn, your appliance is probably really old and you should consider replacing the appliance.

Issues With The Evaporator Coil

The evaporator coil is the component that makes your walk-in cooler or any refrigerator cold. The most common issue with evaporator coils is the icing up of the coils due to the issues mentioned above. When warm air enters the walk-in cooler, it can also reach the evaporator coils and its fans. And with time, it can freeze the evaporator coil or the fans.

In some cases, dust and debris buildup can lead to ice buildup in the evaporator coils because these coils make warm air cold. When they can’t due to dirty coils, condensation occurs more than usual leading to frozen coils.

Furthermore, the same will happen if the evaporator coils or their fans are faulty. Sometimes, the fans become faulty due to ice buildup that is because of the inflow of warm air inside the walk-in cooler. This warm air becomes ice. If this is formed on the fans, they won’t rotate, causing the evaporator coils to freeze which will lead to ineffective cooling of the walk-in cooler. This can spoil the inventory stored in the refrigerator.

Keep in mind that the evaporator coil fans can malfunction on their own as well and they will cause the same problem.

Thermostat Issues

In some other cases, evaporator coils become frozen due to thermostat issues. It could be that the thermostat is set to a temperature lower than the recommended settings which will lead to icing up of the evaporator coils.

Apart from that, if the thermostat is faulty, it might not sense the temperature correctly and may not signal the compressor to stop functioning at the right time. The walk-in cooler might start freezing everything or in the opposite case, the walk-in cooler might become too warm.

Malfunctioning Auto-Defrost Cycle

The defrost cycle removes ice from evaporator coils. These cycles are timed and occur periodically. When a defrost cycle is triggered, the compressor is turned off. Evaporator coils are installed with a small heater or heating element that begins functioning and removes ice formed on the coils. Keep in mind that a normal amount of ice formation on evaporator coils is fine and for removing it, the auto-defrost feature is installed.

However, if the defrost cycle doesn’t work or the heating element becomes faulty, the evaporator coils will remain iced up and lead to various problems like cooling issues.

Clogged Drain Line

It was mentioned in the last point that evaporator coils are defrosted. This means the ice on the coils becomes water. This water flows outside the refrigerator through the condensate or drain line. It can become clogged due to a lack of maintenance or something else obstructing the line.

Due to this, melted water from the evaporator coils and other parts of the walk-in cooler won’t be drained out. So, it will pool near the drain line. This water can freeze up.

If you see ice near the drain line only, then the drain line is either clogged or obstructed. So, clean the drain line.


Icing up of the interior of a walk-in cooler is not normal. It’s dangerous and can damage the evaporator coils, evaporator fans, and even the compressor. So, if you notice ice buildup in your commercial walk-in cooler, get assistance from a walk in cooler repair Fairfax technician.



Why Is My Walk-In Cooler Not Cooling?

Walk-in coolers are essential machines for restaurants, cafeterias, and food businesses. However, they are usually not noticeable until they develop problems. If your walk-in refrigerator is not cooling, it can spoil the inventory stored in it so you must act fast and consult commercial refrigerator services.

If you’re curious why your walk-in refrigerator is not cooling, here are the causes.

Incorrect Temperature Settings

This is a simple and easy-to-fix cause of a walk-in freezer not cooling. Check the temperature settings of your appliance and make sure they are correct. This is because a commercial facility is a busy place and many workers and staff members use a walk-in cooler.

Sometimes, the settings can be changed accidentally or someone changes the settings intentionally but fails to input the correct temperature.

Thermostat Problems

Most walk-in coolers and commercial refrigerators have an electromechanical thermostat. It includes a temperature sensor and an electric contractor. It works similarly to other thermostats. When the temperature rises to the set degree, the thermostat signals the compressor to start functioning. When the temperature is lowered to set the number, the compressor is turned off.

If your walk-in cooler is not cooling, the issue can be with the settings of the thermostat or the sensor or the thermostat itself is malfunctioning.

We discussed earlier incorrect temperature settings. But revisiting is essential keeping an electromechanical thermostat in mind. They have cut-in and cut-out settings.

Cut-in means the settings when the compressor should turn on and cut-on denotes the settings or temperature when the compressor is sent a signal to turn off. The temperature differential should be optimal. If it’s not, the compressor may turn off too early or keep working for too long. It can lead to temperature inconsistencies and damage to the components of the unit.

Have the settings checked by an expert who can ensure that they are correct. If the settings are fine, then the issue could be with the sensor or the thermostat. Only a technician should replace a temperature sensor or thermostat of a walk-in refrigerator.

The Door Gasket Is Worn

Another simple issue is the door not closing properly. Usually, the doors of the walk-in cooler shut perfectly but if the unit is older or if the upkeep is poor, the gasket will not seal the door. In turn, warm air from the outside with get into the unit, and the cool air will escape from the tiny spaces left by the worn gasket.

So, the unit will either not appear cool enough or the compressor will work longer to cool the unit. In the first case, you have a sign of a problem right away, but in the second case, the problem will not be easy to detect. However, the overworking of the compressor will lead to damage to the compressor and other components.

Let an appliance repair technician inspect the door gasket and suggest a fix. Sometimes, the door gasket is fixable, but a long-term solution is the replacement of the gasket.

Blocked Condenser

Walk-in coolers have a condenser on the roof or above the unit. A condenser turns the refrigerant from gas to liquid. In this process, the heat absorbed by the refrigerant is released outside. So, the condenser enables the refrigerant to throw heat outside. If the condenser is blocked, the heat won’t be released properly and the unit won’t work properly.

So, if your walk-in cooler is not cooling, check out the condenser and make sure it’s not obstructed by anything – not even a wall. Moreover, clean the condenser as well because dust and debris can cause invisible obstructions as well.

Condenser And Evaporator Fan

The condenser fan aids in dissipating heat from the condenser coils and keeping the compressor cool. If the condenser fan is not working, check the fan for obstructions that may be stopping it from rotating and clean the fan. If it’s still not working, the fan motor may be faulty.

An evaporator fan helps in blowing cold air into the cooler. If it’s not working, you should check it as well. First, for obstructions, and then inspect the motor. However, this inspection should be carried out by an expert who can not only check out the said components but also inspect other parts as well to fix the issue.

Damaged Insulation Panels

Walk-in coolers have insulation panels on the walls of the unit that aid in maintaining the temperature inside the unit. But these panels don’t last the entire life of the walk-in cooler so you need to check them if your commercial refrigerator is not cooling.

There are multiple types of insulation panels for walk-in coolers and the lifespan of each depends on the mean temperature of the unit, moisture, and ice.

You should take note of the condition of the insulation panels if they have been on for 10 years. A sign of damaged insulation panels is leaking. But if you want to be sure, hire an expert to check out the panels and if they are past their lifespan, replace them.

Water Leaks

We have already mentioned that insulation damage can lead to leaks, but there are other causes of leaks also that may be the reason your walk-in cool won’t cool. Worn gaskets lead to puddles of water near the unit as well. Moreover, improper installation can cause leaks too.

Plus, check the drain lines of the unit because a blocked drain line will leave no escape for the water so it will stay on the floor of the cooler or leak through the door if the door is opened frequently.

Bear in mind that water leaks not only indicate that something is wrong that you should fix, but they also give way to mold and mildew growth. You don’t want a health inspector to see this. So, find the cause of the leaks and fix it and then properly clean the unit as well.

Frozen Evaporator Coils

Firstly, mild frost on the evaporator coils is considered normal for walk-in coolers but not for residential refrigerators. However, if the buildup layer of ice is thick, it shows that the defrost cycle is not functioning or any other problem is causing this.

The freezing of the coils will restrict the heat transfer process. The compressor is overworked to produce more pressure for a better heat transfer rate. Moreover, if the ice buildup is extreme, the compressor might run all the time.

In this process, the walk-in cooler will consume more power, and the risk of damage to any components increases.

Older Unit

A walk-in cooler that is too old will break down often. For instance; if you replaced the insulation panels and thought that the unit won’t need any other repair in some time, you will notice leaks in the unit. So, you will need to have it repaired again.

Therefore, if your walk-in cooler is struggling to cool and it’s older than 15 years, then you should consider the replacement of the entire unit instead of a repair.


The common causes of a walk-in cooler not cooling are incorrect settings, damaged gasket, thermostat issues, obstructed compressor, fan motor malfunctions, and old age of the unit. Hire a walk in cooler repair Fairfax technician to fix this problem.