Deal with what is underneath first
Before diagnosing anything, move whatever is sitting below the coil. Water dripping onto food, onto packaging that will be opened, or onto a shelf where it runs down onto product is a contamination issue that stands on its own regardless of how the refrigeration is performing. It is also the single most visible fault in a walk-in — an inspector walking into the box sees it immediately.
How the water is supposed to leave
Condensate forms on the evaporator fins, runs down them by gravity, falls into a sloped pan underneath, and exits through an outlet at the pan’s low point into the drain line. Four things have to be true: the fins have to shed the water, the pan has to catch it, the pan has to be sloped toward the outlet, and the outlet has to be clear.
Where it goes wrong
Pan outlet partially blocked
The most common. Grease, biofilm, dust and food debris accumulate at the outlet and restrict it. Water then fills the pan faster than it can leave, and spills over the front edge. The giveaway is dripping that is worst immediately after a defrost cycle and stops between cycles.
Pan corroded or cracked
Pans live permanently wet and get cleaned with chemicals that are hard on metal. They corrode at the seams and along the back edge, where you cannot see without removing the pan. A pinhole at the back produces a drip that appears to come from the coil but is actually running down behind it.
Pan out of level
Brackets loosen, corrode or get bent. A pan tilted away from its outlet pools at the wrong end and overflows there. This also happens after service work where the pan was removed and not properly reseated — worth asking if the drip started shortly after someone else worked on the unit.
Water blowing off the coil
If the box is running very humid, the coil carries more condensate than the fins can shed by gravity, and the fan airflow carries droplets past the pan entirely. The water never reaches the pan at all. This one points back at infiltration — a door, a seal, a panel joint — rather than at the pan, and fixing the pan will not help.
Drain line backed up
The pan is fine, the outlet is clear, and the line beyond it is blocked. Water backs up into the pan until it overflows. Check whether the line is draining at its far end before assuming the pan is at fault.
Telling them apart quickly
- Drip worst right after defrost, nothing in between — restriction at the outlet or in the line.
- Drip constant and slow — pan corrosion or a pan sitting out of level.
- Drip at one specific corner — level problem, and that corner is the low one.
- Fine spray or droplets further out in the box, not directly below the coil — water being carried off the coil by the fans, which means humidity.
- Drip from behind the coil rather than the front edge — pan back seam, which needs the pan dropped to see.
Why this is worth calling about early
Of all the faults on this index, this is one of the cheapest to fix and one of the most expensive to ignore. Clearing an outlet and reseating a pan is a short visit. Losing product to contamination, or having an inspector find water dripping onto food, costs considerably more than the call would have. And a pan that has corroded through has usually been dripping for a long time, which means whatever is beneath it has been getting wet for a long time too.
Questions we get asked
Can I just put a tray under it?
As a same-day measure while you arrange a repair, with product moved out from under the coil. Not as an ongoing arrangement. A tray collecting drip water in a cooler is itself a sanitation problem, and inspectors recognise it for exactly what it is.
Why would the pan be out of level?
Mounts loosen, brackets corrode, and pans get knocked during cleaning. It also happens after a coil has been serviced and the pan was not reseated properly. A pan a quarter of an inch off level will spill from the low corner.
Water drips only right after defrost. Is that normal?
A little water in the pan after defrost is normal. Water escaping the pan is not. A drip that is worst immediately after a cycle usually means the pan is filling faster than the outlet can clear it, which is a partial drain blockage rather than a full one.