Two minutes with the bin pulled out tells you more than an hour of guessing.
The most common cause by a distance
Water restriction. In domestic refrigerators the failure order is nearly always: water filter, then fill valve, then fill tube.
Start with the filter, because it is the cheapest and it is the one people forget. Most manufacturers want it changed roughly every six months. A filter left in for three years chokes down flow enough to produce exactly the small-and-hollow-cube symptom, and people conclude the ice maker has failed.
A note for our North Shore customers specifically: if you are on hard water — much of Essex County is, unlike MWRA-supplied Boston — scale in the fill valve orifice and the fill tube is a genuine and recurring cause here. An inline scale filter on the fridge feed is a cheap preventative that we recommend constantly north of Lynn and almost never inside Route 128.
The frozen fill tube
A specific, extremely common fault worth knowing about. The little tube that delivers water into the mould can freeze solid, usually because the valve seeps slightly and a dribble of water freezes in the tube between cycles. You get no ice, and if you look up the tube with a torch you can see the plug of ice.
Thawing it with a hairdryer restores ice for a few weeks and then it comes back — because the leaking valve is the actual cause. If your ice maker has been "fixed" with a hairdryer more than once, the valve is the part that needs replacing.
The harvest side
If the mould is full of good ice that never ejects, the water side is fine and the fault is in the harvest cycle: the mould heater that releases the ice from the tray, the ejector motor and gearcase, or the mould thermostat that decides when to run it. On a modular domestic ice maker these are frequently replaced as one assembly, which is annoying but usually less expensive than the labour of doing it piecemeal.
Undercounter and commercial machines are a different animal
An undercounter ice maker in a Seaport condo or behind a bar is a proper refrigeration appliance with a condenser, a water pump, a cleaning cycle and a drain. Two things dominate:
- Cleaning. These want a descale and sanitise cycle on the manufacturer's schedule. A machine that has never been cleaned makes cloudy, slow, off-tasting ice and eventually stops.
- Drainage. Most need a gravity drain with the right fall, and a lot of them are installed into cabinetry with a drain line that has a belly in it. Standing water in the line means a bin that will not empty and an appliance that ices up internally.
Commercial machines — Hoshizaki, Manitowoc, Scotsman, Ice-O-Matic and the like — have prescribed cleaning intervals that are also a health-inspection matter, not merely a performance one.
Before you call
Confirm the machine is switched on. Almost every ice maker has its own on/off, either a wire bail arm you can lift or a switch in the menu, and it gets knocked into the off position by a bin being pushed back in.
Then check the filter date, look up the fill tube, and look at what shape the ice is. Tell us those three things on the phone and we will usually arrive with the right part.
