Ice on a walk-in floor or ceiling is water that left its intended path and froze. The usual sources are a blocked or frozen drain, defrost meltwater overflowing or spraying, damp air leaking through the door, or moisture reaching a panel seam. Find where the ice starts and follow it back, because chipping it away leaves the leak in place.
Ice on the floor is a slip hazard, and ice on the ceiling can drip or fall onto food and people. It also hides a moisture problem that keeps adding to it. The location of the ice is the best clue.
Read the pattern
| Where the ice is | Likely source |
|---|---|
| Directly below the evaporator | Drain blocked or frozen, pan cracked, defrost water overflowing |
| A stripe from the coil toward the drain point | Drain line partly frozen or sloped wrong |
| At the door threshold and just inside | Door gasket or sweep leak, or wet carts and mop water |
| Along a wall base or panel seam | Seam leak, outside water entering, or condensation running down the wall |
| On the ceiling near the evaporator housing | Fans blowing moisture during or right after defrost, frost building in the housing |
| Ceiling ice far from the coil | Humid air leaking in high on the box, or a roof leak |
| Ice on shelves and walls near the door | Door left open or a poor seal |
How ice ends up on the ceiling
Warm, damp air rises, and any leak near the top of the box lets moisture in that freezes on the cold ceiling. After defrost, fans that start before the coil has drained can blow droplets onto the ceiling and walls, where they freeze in a fine spray. A failed fan-delay switch is a common cause. The defrost cycle page covers that side.
How ice ends up on the floor
Floor ice is usually water that never reached the drain, or water carried in. A drain blocked with slime or frozen by a failed heater sends meltwater across the floor, where it freezes. A door that does not seal draws in humid air that condenses and freezes near the entrance. Wet boots, carts and mop water do the same at the doorway.
What to do
- Make it safe. Put down mats or sand-free traction, warn staff, and keep food out of the drip path.
- Do not chip near the coil or the drain. Tubing and drain lines crack easily.
- Melt it gently. Warm water away from electrical parts, with the drain clear, is safer than tools.
- Follow it back. Note where fresh ice appears first the next day.
- Check the door and the drain. The two most common sources.
- Call if it returns quickly. A heater, switch or seal likely needs replacing.
What a technician checks
- The drain line, trap and, in a freezer, the drain heater.
- The defrost heaters, timer and termination switch.
- The fan delay after defrost.
- The door seal, sweep and threshold.
- Panel seams, the roof and outside walls for water coming in.
Related pages: freezing up and defrost repair, water leaking inside a walk-in, and door, gasket and hinge repair.
Questions about ice on floors and ceilings
Is ice on the floor a food-safety problem?
It is a safety hazard for staff, and it may signal moisture problems that affect food. Keep food off the floor and clean the area after the cause is fixed.
Can I use salt to melt it?
Not inside a food area, and salt corrodes floors and metal. Warm water and a squeegee are safer, with the drain clear.
Why does it come back every week?
The source has not been fixed. A slow-working drain, a marginal gasket or a defrost that does not fully clear the coil are common repeat causes.