Right now

A warming walk-in is a refrigeration call, and the food clock is already running

The FDA Food Code holds cold food at 41 F or below, and the FDA says a closed refrigerator keeps food cold for about 4 hours. Past that you are throwing stock away.

Put a thermometer in the box now and write down the reading and the time. Keep the door shut.

What is probably happening

Ice on the evaporator coil from a failed defrost, so air cannot pass and the box creeps up.
A dirty or blocked condenser, often on the roof or in a hot back room, or its fan has stopped.
A refrigerant leak, a failed compressor, or a door gasket that no longer seals.
This is commercial refrigeration, not the same trade as your rooftop unit. Many commercial HVAC-R companies do both, but ask.

Do this in the next five minutes

Keep the door closed. A full freezer holds for about 48 hours, a half-full one about 24 hours, a refrigerator about 4 hours, if unopened.
Log the box temperature every 30 minutes with the time. Your health inspector will ask.
If the box is above 41 F, start the 4 hour clock on time/temperature control for safety food (meat, dairy, cut produce, cooked rice). Serve or discard within 4 hours.
Move the highest value product to another cold unit or to ice if you have it.
Call a commercial refrigeration contractor and say it is a walk-in with product at risk. Ask for the earliest slot.

Do not

Do not prop the door open to 'check'. Every opening costs you cold you cannot get back.
Do not chip ice off the evaporator with anything hard. The coil is thin aluminum and copper.
Do not guess whether food is safe. If it was above 41 F and you do not know for how long, it goes.

Who to call

A commercial refrigeration contractor (HVAC-R), not a comfort cooling technician

Walk-ins run different refrigerants, defrost controls and pressures from a rooftop unit. Ask whether the company services commercial refrigeration before they roll a truck.

Get a free shortlist The seven questions for this trade

BestHonestPro is a free comparison resource, not a contractor. There is nothing to sign up for and we do not sell your details. When we begin connecting callers to contractors, we will be paid a referral fee by the contractor, never by you, and this line will say so.

What it should cost

$100 to $300 for a thermostat or fan motor, $500 to $1,500 for compressor or evaporator work, over $2,500 for a full system

Walk-in cooler repair, industry vendor guide (Coolrite, May 2026), not neutral research

Source: Coolrite EMS, Ultimate Guide to Commercial Walk-In Cooler Repair, May 2026 (vendor). View source

National published range, not a quote for your job. The full cost table for this trade is on the commercial hvac page.

Ask this contractor, on the phone, before anyone comes out

Tap each one as you ask it.

Do you service walk-in coolers and freezers, and how soon can someone be here?
What is your EPA Section 608 certification type for the technician coming?
Will you check defrost, condenser, gaskets and refrigerant charge, and write down which failed?
If it is a leak, where is it, and can you repair it rather than recharge?
Can you leave a written temperature log entry for my health inspector?

End the call if

A recharge with no leak search on a box that lost cooling slowly.
A tech who is not sure what refrigerant the box uses.

Insurance. Spoiled stock is sometimes covered under a food spoilage or equipment breakdown endorsement on a business policy. Check with your insurer before you throw product away, and photograph and log what goes.

Where this comes from

Not my problem, tap through instead Every commercial hvac answer