The short answer
A refrigerator makes water on purpose — every defrost cycle produces it — so on the NPYXX line a leak is usually a drainage problem rather than a plumbing one. Where the water shows up is most of the diagnosis: inside under the drawers means the drain, at the front on the floor means the drain has already overflowed, and behind the cabinet with a dry interior means the supply. On this page the plumbing comes first, because a wet floor behind a dry cabinet has only one family of explanations.
What an owner actually observes on the NPYXX line
- A puddle at the front of the cabinet, on the floor — The internal trough has filled and is running out under the door. The source is inside even though the water is outside.
- Water under the crisper drawers — Classic blocked defrost drain: melt water backs up in the channel at the back of the compartment instead of leaving it.
- NEAR MISS — water plus a cabinet that is warming up — Deal with the cooling first. A failed defrost produces both at once, and the leak is the smaller half of that fault.
The ranking for the NPYXX line, likeliest first
- The water supply line or its fitting is weeping behind the cabinet — Ranked first on the NPYXX line because the tell is unambiguous: a dry interior with a wet floor behind the unit can only be the supply, and it is visible with a torch and two minutes.
- The filter housing is leaking, usually after a change — A cartridge seated crooked, or an O-ring dragged on installation, weeps under line pressure. It ranks here because it is quick to confirm and cheap to correct.
- The defrost drain is blocked or frozen, so melt water backs up — A silted or frozen drain channel sends every defrost cycle into the compartment instead of the drip tray. It ranks here because the checks above it are quicker, not because it is uncommon.
- The ice maker is overfilling, or the fill tube is spilling past the mould — Bottom of the list, which is the useful part: if there is no ice maker, or no ice outside the bin, this is off the list entirely.
The diagnostic order, and the reason for it
- First — pull the cabinet out and look at the supply joint with a torch — Dry the fitting, lay a sheet of paper under it and come back in an hour. A wet sheet names the joint with no tools and no guesswork.
- Then — look at the filter housing and ask when it was last changed — A leak that began within a day of a change is the cartridge seat. Re-seat it properly rather than tightening anything.
- Only then — find the drain outlet at the back of the compartment and flush it — Take the drawers out, find the trough and ease warm water down the outlet until it runs away freely. Nothing sharp: the channel is soft and a punctured one leaks permanently.
- STOP here if the next check needs a panel off or a meter on live terminals — Everything above can be done with nothing dismantled; past it the checks need test equipment.
Read this before any panel comes off
Safety
Water and electricity share this space. Unplug the appliance or switch off its breaker before mopping under or behind it and before any panel comes off — a capacitor can hold a charge after the power is off. Do not run an extension lead across a wet floor to keep the cabinet going, and turn the water supply off at the shut-off before disturbing any fitting.
When it stops being an owner job
Call when the drain will not clear with warm water, when the leak is at a plumbing joint you cannot reach or re-make, or when water keeps arriving a day after the ice maker was switched off. On the NPYXX line, call rather than continue if the drain channel has to be reached from behind the evaporator cover. Call immediately if water is reaching an electrical connection, if the flooring is lifting, or if there is water plus a warming cabinet — that pair is the defrost system and it will not settle on its own.
Other faults covered for the NPYXX line
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
