Refrigeration Water Leaks: Water or Ice on the Floor

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Water on the floor of a walk-in, a puddle under a prep table, or a sheet of ice spreading from a freezer door is more than a cleanup job. It is a slip hazard for your staff, it can drip onto food and packaging, and it is usually the first visible sign of a drain, heater, defrost or door problem that will get worse. This page helps you find where the water is coming from, what staff can safely do, and what a technician fixes. It is part of our Commercial Refrigeration Help Center.

First, find where the water comes from

Where the water shows up is the best clue to its cause. Dry the area, then watch it for an hour or through a defrost cycle.

• Inside a walk-in, under the evaporator (the fan coil near the ceiling): drain pan, drain line or defrost problem.
• Outside a walk-in, at the base of the door: door heater, gasket, sweep, or water tracking out from inside.
• Frost or drips around the door frame or ceiling: warm, humid air getting in.
• Under a reach-in, undercounter or prep table: condensate pan, drain tube or a unit that is not level.
• Under an ice machine: bin drain, water fittings or the floor sink.
• At the floor sink: a clogged floor sink or drain backing up.

The usual causes

Clogged or frozen evaporator drain

Every evaporator collects water as frost melts or moisture condenses on the coil. That water runs into a pan and out through a drain line. When the line clogs with sludge, or freezes, the pan overflows onto the floor, and in a freezer the overflow turns into ice. Turbo Air's walk-in troubleshooting table lists "Ice accumulating in drain panel" with these causes: "Defective heater", "Drain line plugged", "Defective drain line heater" and a "Defective timer or defrost thermostat" (Turbo Air). Freezer drain lines carry a heater cable to keep them open; when that heater fails, the line freezes a little more each defrost until it blocks.

Defrost that does not finish

If a defrost ends before the coil is clear, Turbo Air explains, "a partial defrost results and the residual water and slush will re-freeze into ice during the next cycle" (Turbo Air). The ice builds on the coil and in the pan, and on air defrost systems Turbo Air lists "water spitting out of the fans or coil" as a symptom of ice forming in the coil. Failed defrost heaters, a defrost termination thermostat, the timer or controller settings, or too few defrosts for the load are the usual causes. Our walk-in freezer ice buildup page covers ice problems in detail.

Door heaters, gaskets and doors left open

Warm, humid kitchen air that gets into a cooler or freezer condenses on the coldest surfaces. Kolpak's walk-in manual says "Frost or condensation appearing around the door jamb or heated pressure relief vent indicates that the electric heater is inoperable, or excessive moisture is present," and that the door gasket should seal "around the entire door perimeter" (Kolpak). Norlake warns against leaving entry doors open for more than five minutes, "which can cause a film of ice or moisture to form on floor, ceiling and wall surfaces," and suggests vinyl strip curtains to reduce warm air coming in (Norlake). Propped doors during deliveries, torn gaskets, a door sweep that no longer touches the floor, and a door closer that does not pull the door fully shut all feed the problem.

Reach-ins, undercounters and prep tables

Most self-contained units send defrost water to a pan near the compressor, where heat from a heater or a hot refrigerant line evaporates it. If the evaporating heater fails, the drain tube cracks or comes loose, the unit is not level, or the pan is overloaded because a door is not sealing, water ends up under the unit. A drain tube clogged with food debris sends water into the cabinet instead.

Condensate pumps and floor sinks

Where there is no gravity drain, a small condensate pump lifts the water away. A stuck float or a failed pump means overflow. California's code requires walk-ins, ice machines and ice bins to drain through indirect waste pipes and an air gap into a floor sink (CalCode 114193), so a clogged floor sink can look like a refrigeration leak. Check it before assuming the equipment is at fault.

Ice machines

Bin drains, water supply fittings, distribution tubes and an overfull bin are the usual sources. Our ice machine problems page has the checks.

Why an inspector cares

CalCode requires that equipment be "kept clean, fully operative, and in good repair" (CalCode 114175), and water dripping from a coil onto food or packaging is a contamination risk as well as a housekeeping one. Standing water, ice on a walk-in floor, mold on door frames, and drain lines that do not run to an air gap at a floor sink are all things an inspector can write up. Our health inspection refrigeration checklist lists what else they look at.

Safe checks your staff can make

1. Make the floor safe: signs, mop, and move product away from any drip.
2. Check the unit's thermometer and write down the temperature and time. A leak plus rising temperature means call now.
3. Look at the door: does it close by itself and seal all the way around? Are strip curtains in place? Is there frost on the frame?
4. Look up at the evaporator with a flashlight. Is the coil white with ice? Is water dripping from the pan or the fans?
5. Check the floor sink for standing water or debris.
6. For reach-ins and prep tables, check that the unit is level and that nothing is pinching the drain tube.
7. Take photos and note when the water appears, for example after defrost or after deliveries.

Leave drain heaters, defrost heaters and anything behind electrical covers to a technician. Pouring hot water down a frozen freezer drain can clear it briefly, but the ice comes back if the drain line heater has failed, and water near heater wiring is a shock hazard.

What a technician does

We clear and flush the drain line and pan, then test the drain line heater, defrost heaters and defrost termination control, and check the defrost schedule against the load and how often the door opens. We inspect the pan for cracks and the drain for correct slope and routing to the floor sink. At the door we test the frame and vent heaters, check gaskets, the sweep and the closer, and look at the strip curtains. On self-contained units we check the condensate evaporator heater or hot gas loop, and level the cabinet. If the coil is iced, we find out why before defrosting it, because an iced coil can also mean low refrigerant or a failed fan. Norlake recommends quarterly preventive maintenance by a certified technician that includes checking door gaskets and the door sweep, inspecting heated vent ports and cleaning the coils (Norlake).

Drain and door problems are some of the most common findings on our walk-in cooler repair calls, and they are among the signs a walk-in cooler is failing. Every repair carries our 1-year parts and labor warranty.

Preventing leaks

• Keep doors closed, keep strip curtains in good shape, and do not prop walk-in doors during deliveries.
• Clean gaskets regularly; Kolpak says gaskets and door sweeps "should be cleaned frequently with a mild detergent" (Kolpak). Replace any that are torn or flattened.
• Have drains flushed and drain line heaters tested as part of routine service.
• Keep floor sinks clear.
• Put drains, heaters and doors on a maintenance plan; our maintenance schedule shows how often each task comes around, and our post on preventive refrigeration maintenance explains why it pays.

Book a leak diagnosis

Frequently asked questions

Written and reviewed by Jim McKinny, owner of Cool Aid Air Conditioning & Refrigeration — California C-20 and C-38 licensed, EPA Universal certified, second generation of a family business serving the Bay Area since 1966. Every job we complete is backed by our 1-year parts & labor warranty.