Search guides

Fix a commercial refrigerator that will not cool

We'll confirm the symptom, rule out power and thermostat setting, then check the door seal, condenser coils, vents, evaporator fan, and defrost system—or tell you when to call a pro.

Troubleshooting · Home appliances
15–60 min
What you'll need
  • Thermometer (to check fridge temps)
  • Vacuum with brush attachment (for condenser coils)
  • Screwdriver set (for grilles and access panels)
  • Towels (if thawing frost)
Step 1 of 11

Quick triage — pick your path

Quick triage — pick your path

Choose the option that matches what you see. You can jump straight to that section.

Show full guide

Steps

Goal: Confirm the symptom, rule out power and thermostat, then isolate the cooling fault.

  • Confirm the compressor runs (hum from the back or bottom) and that fridge temps are too warm. Use a thermometer—commercial fridge should be 34–40°F (1–4°C) for food safety.
  • Good: The compressor runs but temps are above target—cooling fault. Proceed to Check power and thermostat.
  • Bad: The compressor does not run—check power first. See When to get help.

Check power and thermostat

Goal: Rule out power loss and incorrect thermostat setting before opening the fridge.

  • Verify the refrigerator is plugged in and the circuit breaker has not tripped. Commercial units often use dedicated circuits.
  • Check the thermostat dial or digital setting—it may have been turned too warm. Set the control to the middle or recommended setting. Wait 24 hours and recheck temps.
  • Good: Power is on and the thermostat is set to a cold setting. Proceed to Door seal and coils.
  • Bad: Breaker trips when the fridge runs—call a pro.

Door seal and coils

Goal: Check the door seal and condenser coils—common causes of poor cooling in commercial units.

  • Inspect the door seal (gasket) around the door or doors. Commercial units see heavy use—seals wear faster. Look for cracks, tears, or gaps. Close the door on a dollar bill—if you can pull it out easily, the seal is weak. Clean with soap and water; replace if damaged.
  • Unplug the refrigerator. Locate the condenser coils—behind the unit, underneath, or behind a grille. Commercial kitchens produce grease and dust; coils clog faster. Vacuum dust and lint with a brush attachment. Plug back in and wait 24 hours.
  • Good: Seal is snug and coils are clean. Proceed to Vents and evaporator fan.
  • Bad: Seal was damaged or coils were very dirty—fix those first and retest.

Vents and evaporator fan

Goal: Confirm vents are clear and the evaporator fan circulates cold air.

  • Check that pans, containers, or food are not blocking the vents. Commercial units are often packed—blocked vents are common. Rearrange items so air can circulate.
  • When the compressor runs, you should hear the evaporator fan. If the fan does not run, frost may be blocking it—see Frost and defrost. If the fan is dead, replace it per your model.
  • Good: Vents are clear and the fan runs. Proceed to Frost and defrost.
  • Bad: Fan is dead or vents were blocked—fix and retest.

Frost and defrost

Goal: Address heavy frost that blocks the evaporator fan. Defrost system failure requires a pro.

  • If frost is thick in the evaporator area, unplug the refrigerator and leave the door open 24 hours to thaw. Place towels to catch water.
  • Plug back in and test. If frost returns quickly (within days), the defrost heater, thermostat, or timer has failed—call a pro.
  • Good: No heavy frost, or frost does not return quickly. The fridge should cool.
  • Bad: Frost returns quickly—defrost system failure. Call a technician.

When to get help

Call an appliance technician if:

  • The compressor does not run or makes knocking or grinding noise (sealed system failure).
  • Frost returns quickly after thawing (defrost system failure).
  • You have cleaned coils and checked the seal and it still does not cool.
  • You are not comfortable working with electrical parts.

Do not attempt to repair the sealed system or refrigerant lines yourself.

Verification

  • Fridge temperature is 34–40°F (1–4°C) for food safety.
  • The compressor runs in cycles and the evaporator fan circulates air.
  • No heavy frost buildup in the evaporator area.
  • Door seal is snug with no gaps.

Escalation ladder

Work from the device outward. Stop when the problem is fixed.

  1. Confirm symptom Verify the compressor runs but temps are too warm; rule out a different problem.
  2. Power and thermostat Check circuit breaker and thermostat setting.
  3. Door seal and condenser coils Inspect the door seal and clean the condenser coils.
  4. Vents and evaporator fan Clear blocked vents and confirm the evaporator fan runs.
  5. Frost and defrost Thaw heavy frost; if it returns quickly, defrost system has failed.
  6. Call a pro Compressor or sealed-system failure, defrost failure, or not comfortable—call an appliance technician.

What to capture if you need help

Before calling support or posting for help, have these ready. It speeds everything up.

  • Whether the compressor runs
  • Fridge temperature
  • Door seal condition
  • Condenser coil condition (dirty or clean)
  • Whether vents are blocked
  • Whether evaporator fan runs
  • Steps already tried

Does the compressor run but the fridge is not cold enough?

Check that you hear a hum from the back or bottom and that fridge temps are too warm. Use a thermometer—commercial fridge should be 34–40°F for food safety.

Confirm the compressor runs (hum from the back or bottom) and temps are too warm. Good: compressor runs but temps above target—cooling fault. Bad: compressor does not run—check power first or call a pro.

Yes No

You can change your answer later.

Is power on and the thermostat set correctly?

Circuit breaker and thermostat setting can prevent cooling. Commercial units often use dedicated circuits.

Verify the fridge is plugged in and the circuit breaker has not tripped. Check the thermostat—set to middle or recommended. Wait 24 hours. Good: power on and thermostat set cold. Bad: breaker trips or thermostat was too warm—fix those first.

Yes No

You can change your answer later.

Is the door seal tight with no gaps?

Commercial units see heavy use—seals wear faster. Close the door on a dollar bill—if it pulls out easily, the seal is weak.

Inspect the door seal. Look for cracks or gaps. Close the door on a dollar bill—if you can pull it out easily, the seal is weak. Clean or replace. Good: seal snug. Bad: seal damaged—replace it.

Yes No

You can change your answer later.

Clean or replace door seal and test

Clean the seal with soap and water. If cracked or torn, replace with a matching part. Wait 24 hours and check temps. If still not cooling, proceed to condenser coils.

Done

Are the condenser coils clean?

Dirty condenser coils block heat transfer. Commercial kitchens produce grease and dust; coils clog faster.

Unplug the fridge. Locate the condenser coils. Vacuum dust and lint. Plug back in and wait 24 hours. Good: coils clean. Bad: coils were very dirty—cleaning often fixes cooling.

Yes No

You can change your answer later.

Clean coils and test

Vacuum the condenser coils. Plug back in. Wait 24 hours. The fridge should cool better. If not, proceed to check vents and evaporator fan.

Done

Are the vents inside clear and is the evaporator fan running?

Blocked vents or a dead evaporator fan prevent cold air from reaching all areas.

Check that pans and food are not blocking vents. Listen for the evaporator fan when the compressor runs. If the fan does not run, frost may block it—thaw and retest. If the fan is dead, replace it. Good: vents clear and fan runs. Bad: fan dead or vents blocked—fix and retest.

Yes No

You can change your answer later.

Clear vents or replace evaporator fan and test

Clear blocked vents. If the fan is dead, replace it per your model. Thaw first if frost is blocking the fan. Retest. If still not cooling, check for frost buildup.

Done

Is there heavy frost in the evaporator area?

Heavy frost can block the evaporator fan. If frost returns quickly after thawing, the defrost system has failed.

If frost is thick, unplug and thaw 24 hours. Plug back in. Frost returns quickly: defrost system failed—call a pro. No frost or frost slow to return: thermostat or sensor may be faulty—call a pro if you are not comfortable. Good: no heavy frost. Bad: frost returns quickly—defrost failure.

Yes No

You can change your answer later.

Thaw and test or call a pro

Thaw 24 hours. If frost returns quickly, the defrost heater, thermostat, or timer has failed—call a technician. Do not attempt defrost system repair.

Done

Call a technician

Call an appliance technician if: the compressor does not run or makes knocking or grinding noise (sealed-system failure); frost returns quickly after thawing (defrost failure); you have cleaned coils and checked the seal and it still does not cool; or you are not comfortable working with electrical parts. Do not attempt sealed-system or refrigerant repair yourself.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why would a commercial refrigerator run but not cool?
Common causes: thermostat set too warm, bad door seal (heavy use wears seals faster), dirty condenser coils, blocked vents inside, failed evaporator fan, or defrost system stuck. Less often: faulty thermostat or sealed-system failure. Check the easy items first.
Can I fix a commercial refrigerator that will not cool myself?
Yes, for many causes. You can clean condenser coils, replace a door seal, clear blocked vents, and sometimes replace the evaporator fan. Compressor or refrigerant issues require a professional—do not open the sealed system.
When should I call a technician for a commercial refrigerator that will not cool?
Call a pro if the compressor does not run or makes unusual noise, if frost returns quickly after thawing (defrost failure), if you have cleaned coils and checked the seal and it still does not cool, or if you are not comfortable working with electrical parts.

Rate this guide

Was this helpful?

Continue to