A Guide for Diagnosing Issues in Walk-In Refrigeration

Walk-in coolers or freezers, over time, are not immune from issues and problems that will cost you time and money. Awareness about these issues will prevent you from spending a lot of money in dealing with them. The following are some tips and solutions on how to identify and resolve those issues.

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The Evaporator is not Performing its Usual Function.

Remember that the evaporator system is important because it is the one responsible for cooling the air inside the unit. If it does not do its function, the cooler or freezer loses its use.


Here are Some Common Causes Why your Evaporator may not be Functioning Properly.


1.      Ice Keeps on Building Up.

Ice build-up is typically made by the presence of warm air inside the unit. This warm air will cause extra moisture to the unit that can lead to ice buildup. Lack of airflow and a broken defrost system are other causes of the ice build-up inside your walk-in freezer.

Ice Build-up


2.      Defective or Malfunctioning Evaporator Fans.

Once the evaporator fans of the system are broken or malfunctioning, the air inside the cooler or freezer will not be able to circulate.


3.      Malfunctioning or Out-of-standard Thermostat.

If the thermostat is not functioning properly, the temperature is not accurate which will then cause ice to build up.



Condenser Issues or Problems

An area with good ventilation is needed for a condenser to perform best. A well-ventilated area with a controlled temperature will enable the condenser to easily remove heat. For enclosed spaces, fans are necessary for air to circulate because closed spaces need openings for cold air to enter and exit. If the heat of the condenser is not needed, it should be expelled directly outside.

Condenser Fan


The Following are Some Reasons Why a Condenser Malfunctions.


1.      Insufficient Ventilation.

Sufficient ventilation or circulation of air is needed for a condenser to do its purpose properly. If there is no proper ventilation, the condenser may malfunction.


2.      Dirt and Dust

Dirt and dust, when not removed regularly will accumulate resulting in the condenser coil not functioning properly. If it malfunctions, the unit will not cool properly.

Dust and Dirt Build-up



Compressor Malfunction:

The compressor is the heart of the refrigeration system, once this component fails the whole system will break down. The compressor’s main function Is to compress gas that handles the raising of temperature and converting it into high temperature.

Compressor Walk-in Cooler


Here are Some Common Signs that Indicate your Compressor may not be Working Properly.


1.      Insufficient Cooling:

Your walk-in cooler or freezer does not meet the desired temperature.


2.      Strange Noise

Strange noise coming from the compressor might be a sign of internal damage.


3.      Overheating

This indicates that the compressor is not in its optimal condition. It is working harder to meet the desired output.


4.      Unable to Start.

The reason can be broken down into an insufficient power supply, a defective or malfunctioning start capacitor, or a broken motor.

Broken Compressor Motor


5.      Warm Air is Coming Out from the Vents.

The compressor unit cannot cool down the unit because it cannot release the needed level of refrigerant.


6.      Leaking Refrigerant

Refrigerant leaks will damage the compressor especially if it cycles between on and off repeatedly.


The following is the Step-by-Step Procedure for Diagnosing Compressor Issues.


Step 1: Check the Outlet to Which the Cooling Unit is Connected. 

Power output is essential for a compressor to function properly. Check if the output of the power is the same as the operating requirement of the compressor unit.

Checking the Power Output


Step 2: Locate and Check the Capacitors Used in the System

Start and run capacitors are two of the most important components of a compressor. The former helps the motor start while the latter maintains the motor’s power for it to function. These should be regularly checked and maintained to ensure the compressors’ smooth operation.


Step 3: Check the Compressor Motor.

One reason why a motor is malfunctioning is because it may not have sufficient power and one of the components helping the motor turn is the motor capacitor. Check and measure the reading to ensure they are within standards, if not, replace.


Step 4:. Inspect the Compressor Valves. 

Do a thorough inspection of the compressor valves. Compressor valves help the motor work efficiently and effectively. Check for any damages like leaks or wearing out of valves.


Step 5: Monitor the Level of Refrigerant.

If the level of refrigerant is low, it can be because of a leak. When there are leaks in the refrigerant system, repair the leak first before adding more refrigerant. Since refrigerants are hazardous to the health and environment, ask a licensed technician to replace them for you.



Placement of the Products and Shell Issues

There are instances wherein the placement of the products affects the temperature of the walk-in cooler or freezer. Observe proper placement and spacing for the unit to work in good condition. In some instances, issues in the shell of the walk-in may also affect the performance of the walk-ins.

Placement and spacing of the products inside the walk in cooler or freezer


Here are Some Factors to Consider as to Why your Walk-ins may not Function Well.


 Cracks, Leaks, and Loose Panels

Cracks, leaks, and loose panels will also prevent your walk-in cooler or freezer from working properly. The cold air that is supposed to be inside is escaping, which will lead to frost build-up. 


 Doors are not Sealed.

Always check the door if it’s properly closed and examine for possible cracks in the door gaskets to prevent the warm air from entering. Have a professional repair of major defects or cracks.

Walk-in Cooler Doors


 Too Many Items

Avoid overfilling your walk-in freezer and only store the required amount of items. Too many items can cause insufficient airflow.

Stored items on the walk-in cooler


Items are Placed in Front of the Evaporator.

Keep your evaporator fan from any blockage, in this way, the cold air will circulate freely and avoid malfunctioning of the evaporator.



Other Problems you may Encounter and their Possible Cause and Solutions:


Musty or Moldy Smell

Foul and moldy smells from your walk-in freezer could indicate the presence of germs and bacteria that have built up over time. The unpleasant odor is usually caused by hidden spills that go undetected or unaddressed for a while. Allowing such bacteria to remain in your freezer can lead to contamination and ultimately result in a waste of money.

Molds, germs, and bacteria


Clean up your walk-in freezer regularly by using mild soap and water, adding vinegar or baking soda will also help to eliminate the musty smell.


Unusual Sound

Unusual or strange sounds from your walk-in cooler or freezer may indicate that something is wrong. When the condensing fan or evaporator’s fan is full of dirt, debris, or ice buildup, it can cause noise and difficult operation.


To identify the root cause of the unusual noise or sound, it is advisable to seek professional help in troubleshooting. The licensed technician will assist you in finding the best solution to ensure your walk-in freezer is working properly.


Water Leaked Inside.

Broken drain pans, old insulation, broken seals, and clogged drain holes are the most common causes of water leaking inside your walk-in freezer. These may lead to a serious problem if it is left unsolved.


Troubleshoot what causes the leak first. For simple leaks, you may repair it by yourself but if it is a major leak, you may require professional assistance depending on the leakage case. Attempting a fix on your own may not always suffice.


Power is on, but the Control Board does not Show Anything.

Troubleshoot the problem by checking if there is a power output, if yes, check if the output power is sufficient to support the operation of the unit. If there are no issues with the power supply, check the control board as it may be the one that is malfunctioning or defective.


Temperature Control Board


Reset and restart the main breaker. If there are no issues, the problem may be the control board. Troubleshoot and check for defects and replace or repair them if possible.


The Compressor does not Function, but the Control Board Shows a Display.

The start relay’s main function is to power the compressor. If the compressor does not function, check this component because it is responsible for starting and ensuring that the compressor runs correctly. If the relay is in good condition, the compressor may be defective.

Start Relay


Unplug the walk-in freezer. Open the compartment at the back, unplug the start relay on the compressor, and shake it. If you hear unusual sounds like broken tiny pieces, your start relay must be replaced. Contact a professional to troubleshoot and repair other defective components.


High Discharge Pressure during Operation

Accumulated dirt on the condenser, insufficient airflow, or refrigerant overcharge are the three common causes of high discharge. They all prevent the condenser from working in its optimal condition.


Clean the condenser regularly, place it in a well-ventilated area, and adjust the refrigerant charge. Frequent and regular cleaning should be done on the unit’s components while also observing the standard operating procedures.


Low Discharge Pressure is Observed

There could be a refrigerant leak or a clogged filter. These two results in a decreased cooling of the unit.


Troubleshoot the problem by checking for leaks. Replace dirty and damaged filters. If the damage on the filter is minor, you may repair it but get the services of a professional when dealing with refrigerant as it is a hazardous substance.


The Actual Cold Storage Temperature and Control Temperature Panels are not the Same.

There may be an issue with the thermostat if your walk-in cooler or freezer is not maintaining the desired temperature. The thermostat sends a signal to the compressor to activate the refrigeration cycle when the temperature rises above the desired range. Once the desired temperature is achieved, the thermostat signals the compressor to shut off to maintain the desired temperature.


Troubleshoot the problem by checking the condition of the thermostat. See to it that it is calibrated, if not, have it repaired and calibrated. Check the thermostat regularly and use a reliable thermometer inside your walk-in cooler or freezer for accurate temperature measurement.


Excessive Frost on the Evaporator Coil

Most of the time, the common cause of this problem is the following: a dirty evaporator coil, damaged fans, low levels of refrigerant, or poor insulation. All of these may result in ice build-up on the coil.

Ice Build up on the coil


Clean the coils regularly, if the fans are damaged, repair or replace them immediately depending on the severity of the damage. If the cause is the refrigerant, check for leaks, monitor the freon levels, and refill as needed. The most important part to keep in mind is that good insulation will ensure that frost and ice build-up will be avoided.


High-Temperature Reading

The unit exceeded the standard temperature limit. This may be caused by leaving the door open for a prolonged period.

High Temperature


Find the problem by troubleshooting what causes the high reading. It is important to monitor the temperature and ensure the door is closed properly. If necessary, a self-closing door should be used. Frequent and regular monitoring of temperature is important while also ensuring that doors are properly closed when the unit is not in use. Repair small cracks and holes as they may affect the temperature inside the unit.


The Coil does not Clear Off Frost During the Defrost Cycle.

Either the defrost cycle ended too soon or the heater isn’t working.


If the defrost cycle ends too soon, it could be due to issues with the terminating components. As a temporary fix, leave the temperature switch disconnected and contact a professional to troubleshoot the root cause of the problem.



Tips on How to Avoid these Problems:


1.      Schedule Regular Maintenance

Schedule regular preventive maintenance on the unit to do a thorough check of all components. Ask the help of professionals to conduct the maintenance to prevent damage to the unit. Components for repair will also be identified if regular maintenance is done.

Technicians are needed for regular maintenance


2.      Make Sure to Keep your Door Closed at All Times and Secure.

Doors should always be airtight and always closed when not in use. Do this to avoid excessive condensation that results in ice build-up.


3.      Check the Temperature Regularly

Regular temperature checking is essential to ensure that the unit meets the standard temperature requirement. By regularly doing this, problems with temperature can be identified easily.

Temperature Setting


4.      The Defrost Cycle Should be in Good Condition.

Regularly check the defrost heater if it is in good working condition. This is important because this helps eliminate the build-up of ice on the unit’s components.


5.      Sufficient Airflow

Proper ventilation and spacing help in maintaining the efficiency of the walk-in unit. Food or objects that are stacked together can affect the cooling performance.




Identifying the issues and problems regarding walk-in coolers or freezers is just one part of the solution. We need to be able to solve these issues to prevent excessive damage to our business and cost us time and money. By taking preventive measures, we will be able to prolong the lifespan of our units. Hire professionals for help, especially for complex issues. This will prolong the life and usefulness of our freezer or coolers.


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