Why Your Walk-In Cooler Keeps Freezing Up (and What to Do About It)

A walk-in cooler that keeps freezing up isn’t just annoying — it’s a warning sign. For restaurants, hotels, and commercial kitchens, this is one of the most common commercial refrigeration repair calls we see — and it’s usually preventable. Ice buildup can damage equipment, ruin inventory, drive up energy costs, and eventually lead to a full breakdown at the worst possible time.

If your walk-in cooler is icing over, here’s what’s actually causing it — and what you can do before it turns into an emergency service call.

The Most Common Reasons Walk-In Coolers Freeze Up

1. Poor Airflow Inside the Cooler

Walk-in coolers rely on constant, even airflow to maintain proper temperatures. When airflow is restricted, cold air settles in one spot and freezes moisture in the air.

Common airflow issues include:

• Overstocked shelves blocking evaporator fans

• Product stacked too close to walls or vents

• Damaged or non-functioning evaporator fans

What to do:

• Keep at least 4–6 inches of clearance around vents and walls

• Don’t stack boxes directly in front of the evaporator unit

• Listen for fan noise — silence is a red flag

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2. Damaged or Worn Door Gaskets

A failing door gasket lets warm, humid air sneak into the cooler. When that warm air hits cold surfaces, moisture freezes — fast.

Signs your gasket is the culprit:

• Visible cracks, tears, or flattening

• Condensation or ice around the door frame

• The door doesn’t seal tightly when closed

What to do:

• Inspect gaskets weekly

• Clean them regularly to prevent stiffness

• Replace damaged gaskets promptly — they’re cheaper than a compressor

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3. Door Left Open Too Often (or Too Long)

Busy kitchens are tough on walk-in coolers. Frequent door openings introduce warm air and moisture, which accelerates ice buildup.

What to do:

• Train staff to open the door only when needed

• Make sure doors close automatically and completely

• Consider strip curtains if traffic is heavy

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4. Faulty Defrost System

Your walk-in cooler has a built-in defrost cycle designed to melt ice off the evaporator coils. When this system fails, ice just keeps building.

Defrost problems can include:

• Failed defrost heaters

• Malfunctioning defrost timers

• Bad termination switches or sensors

What to do:

• If ice keeps returning after manual removal, call for service

• Defrost issues usually require professional diagnosis

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5. Low Refrigerant Levels

Low refrigerant pressure can cause coils to run colder than designed, leading to excessive ice formation.

Important note: Low refrigerant doesn’t mean “top it off.” It usually means there’s a leak — and ignoring it can destroy your system.

What to do:

• Call a licensed technician

• Do not attempt DIY refrigerant fixes

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6. Dirty Evaporator Coils

Dust, grease, and grime act like insulation on coils, preventing proper heat transfer and causing uneven cooling.

What to do:

• Schedule routine coil cleaning

• Keep kitchen grease and debris away from the evaporator area

What Not to Do

• ❌ Don’t chip ice off with sharp tools — you can puncture coils

• ❌ Don’t ignore recurring ice buildup

• ❌ Don’t crank the thermostat lower to “fix” cooling problems

These shortcuts often lead to bigger, more expensive failures.

When to Call a Professional

If your walk-in cooler:

• Freezes up repeatedly

• Has ice on the evaporator coils

• Struggles to maintain temperature

• Shows water pooling or leaks after defrosting

…it’s time for a professional inspection.

Catching the issue early can mean the difference between a minor repair and a full system replacement.

Preventative Maintenance Saves Money

Recurring ice buildup is often a sign that your walk-in cooler needs professional attention. A routine walk-in cooler maintenance visit can identify airflow issues, failing door gaskets, defrost system problems, and refrigerant concerns before they lead to food loss or emergency downtime.

If you operate a restaurant, hotel, bar, or commercial kitchen, scheduling regular commercial refrigeration service is one of the simplest ways to extend the life of your equipment.

Final Thought

A freezing walk-in cooler isn’t random — it’s your system asking for attention. Regular inspections, good loading habits, and fast response to small issues can keep your cooler running efficiently and your business protected.

If you’re dealing with recurring ice buildup or need reliable walk-in cooler repair, Repair Pros Services Inc. provides professional commercial refrigeration repair for restaurants and hospitality businesses in Chattanooga and the surrounding areas.

Because downtime isn’t an option.

Contact Us