The short answer
On a True Professional refrigerator, a refrigerator makes water on purpose — every defrost cycle produces it — so a leak is almost always a drainage problem rather than a plumbing one. Where the water appears tells you which: inside under the crispers means the drain, on the floor at the front means the drain has overflowed, and behind the cabinet means the supply. A commercial deck inside a built-in domestic cabinet means the sealed system is strong and the installation is the weak point, which inverts the usual ranking.
What you are actually seeing
- Water standing under the crisper drawers — Classic blocked defrost drain: the melt water has nowhere to go.
- A slab of ice at the back wall of the freezer section — The drain has frozen rather than merely silted up.
- NEAR MISS — the leak only appears when the dishwasher or the sink runs — Then the water is not coming from the refrigerator at all. Check what shares that floor.
Causes, most likely first on this refrigerator
- Defrost drain blocked or frozen, so melt water backs up inside the cabinet — Ranked first on True Professional: the drain is the only part of this system that is designed to carry water, so it is the first place to look when water is somewhere else. On this one, remember that the deck is commercial-grade inside a domestic cabinet, so the installation is the weak point rather than the machine.
- Condensation rather than a leak — humid air meeting cold surfaces — Second: it explains water with no plumbing involved, and a paper test settles it in ten minutes.
- The water supply line or its fitting is weeping behind the cabinet — Third: a built-in column is plumbed in at installation and then never moved, so the joint behind it is the one nobody has ever looked at.
- The water is reaching the tray and not staying there — Ranked last here, deliberately: it is the last stop in the water path, and a cabinet that has been moved recently is usually no longer sitting as it was.
Check in this order, and why
- First — look for water or ice under the crisper drawers and at the back of the compartment — Water pooling inside the cabinet is a drain fault until proven otherwise, and nothing else looks like it.
- Then — test the seal with a strip of paper all the way round the door — Free movement anywhere means room air is walking in at that point.
- Only then — check the cabinet is level with a slight backward tilt, and look at the tray — A forward tilt turns the whole drainage system round, and it is the cheapest thing on this page to correct, which is why it comes after everything above it.
What an owner can safely check
- Find the drain outlet at the back of the compartment and flush it — Take the drawers out, find the trough and its outlet, and ease warm water down it until it runs away freely.
Tools: warm water, turkey baster or syringeAbout 25 min
- Inspect the supply connection and dry it, then check again an hour later — Dry everything, put a sheet of paper under the joint and come back. A wet sheet names the joint without any tools.
Tools: torch, paper, clothAbout 20 min
- STOP at the first step that needs a meter on live terminals — That is where an owner check ends and a service visit begins, and nothing above this line needs one.
Before you open anything
Safety
Water and electricity share this space. Unplug the cabinet or switch its breaker off before you mop up anything under or behind it, and before any panel comes off. Do not run an extension lead across a wet floor to keep the unit going.
When it stops being an owner job
Call when the drain will not clear with warm water, when the leak is behind the cabinet at a plumbing joint you cannot reach or re-make, or when water keeps arriving after the ice maker has been off for a day. Call immediately if water is reaching an electrical connection, if the floor covering is lifting, or if there is water plus a rise in cabinet temperature — that pair means the defrost system, and it will not fix itself.
Nearest pages of this class
What this page does not cover
This page is written for the True Professional refrigerator as a class, not for one family or one model line. Where a family-specific page exists for your unit it is linked above and it is the more specific answer. Deliberately not here: part numbers, wiring colours, torque figures and any measured value, all of which differ by family.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
