Water inside a walk-in almost always comes from one of four places: a blocked or frozen drain, a defrost cycle that overflows the pan, condensation from warm damp air, or a leaking door seal. Find where the water is coming from before you mop it up, because it is a symptom of a fixable cause.
A puddle under the coil or a drip from the ceiling panel is more than a mess. Water on the floor is a slip hazard, water dripping on food is a food-safety problem, and water where it should not be is a sign the box is not managing moisture. In Hattiesburg's humid climate, moisture is the main enemy.
Follow the water
| Where you see it | Likely cause |
|---|---|
| Puddle directly under the evaporator | Blocked or frozen drain, cracked or tilted drain pan |
| Drips from the evaporator housing onto shelves | Overflowing drain pan, fans running during defrost, heavy frost melting fast |
| Wet ceiling panels away from the coil | Condensation from warm humid air, or a roof or wall leak above |
| Water at the door threshold | Door gasket or sweep leak, or melting ice carried in on carts |
| Water along the floor edge | Panel seam leak, floor drain problem, or water tracking from outside |
| Puddle near the drain line exit | Broken or disconnected line, trap issue or clogged discharge |
The drain
Every walk-in coil has a drain pan and a line that carries melted frost out of the box, often through a trap. Slime, food debris and dirt clog it. In a freezer the line runs through a cold area, so it usually has a heater to keep it from icing. If the heater fails or the line is clogged, water backs up and spills or freezes. A drain that ices over can build a block that lifts the pan or pushes water onto the floor.
The defrost cycle
Every defrost sends water to the drain. If a defrost cycle runs too long, if frost has built into a thick block, or if fans start before the coil has drained, water can overshoot the pan and spray. A failed fan delay or termination switch is a common cause. If water drips only around defrost times, that is your clue.
Condensation
Condensation forms when warm, damp air meets a cold surface, and it shows up as sweat on ceiling panels, shelves and lights. It is more likely when the door stays open, when the gasket is poor, when humid air enters after a delivery, or when the box is warmer than it should be. It drips onto food if left alone. Fixing the door seal and traffic usually reduces it more than any part replacement.
Leaks from outside
If the water is on the ceiling far from the coil and only appears after rain, check the roof over the box and the seams. Storm damage can open roof seals or flashing. Water reaching the insulation can travel and appear elsewhere.
What to do right now
- Protect food. Move product out of the drip path and cover what you cannot move.
- Make it safe to walk. Wipe up puddles and put a mat or sign down.
- Trace the source. Note whether it happens at defrost, after rain, or all the time.
- Check the drain visually. Look for standing water in the pan and ice on the line.
- Look at the door. Light around the gasket, frost near the edge.
- Call a technician if the source is not obvious or the leak returns.
Related pages: freezing up and defrost repair and door, gasket and hinge repair.
What a technician does
- Flushes the drain and checks the trap and discharge point.
- Tests the drain line heater on a freezer.
- Checks the defrost timer, heaters and termination and fan-delay switches.
- Inspects the pan for cracks and tilt.
- Tests the door seal and looks for air leaks.
- Looks at the roof and panel seams if the water is not from the coil.
Water that returns after every defrost is covered in defrost cycle problems. For food kept under a drip, see the food-safety guide, and for a regular check of drains and gaskets, the maintenance checklist.
Questions about leaks and water
Is water on the floor a food-safety issue?
It can be. Water can carry contamination, and dripping water on food is a concern to inspectors. Fix the source, clean the area and protect stock.
Why does it leak only after the defrost cycle?
A large amount of melted frost is reaching the pan at once. The drain may be slow, the frost load is heavy, or fans are starting too early. Check the drain and the switches.
Can I use a wet vacuum to keep up?
Only as a temporary measure, and never near electrical parts. It treats the symptom while the cause continues.