An ice maker is a small machine with three jobs: get water, freeze it, and let go of it. Nearly every "no ice" call resolves to one of those three, and you can work out which one before anyone comes out.
Start with the arm or the switch
Absurdly common and worth ruling out first. Most ice makers have a wire bail arm that rides on top of the ice in the bucket; when the bucket is full the arm lifts and production stops. Something shifted in the freezer, or a bag of peas leaned against it, and the arm has been held up for a month.
Newer units use an optical or infrared sensor across the bucket instead. A frosted-over emitter, or a box sitting in the beam, does the same thing. Wipe the little windows on each side wall of the ice compartment.
Then the water
If the arm is down and the machine still makes nothing, follow the water.
Is the dispenser producing water? On a unit with a water dispenser in the door, press it. Good flow means the supply, valve and filter are broadly fine and the fault is downstream. No flow or a trickle means you have found it.
The filter. A filter left in past its life restricts flow enough that the fill valve cannot deliver a full charge in the seconds it is open. The ice maker then produces small, hollow or partial cubes before stopping entirely. Six months is the interval; nobody hits it. If your ice went small before it went away, replace the filter first — it is an inexpensive part and it accounts for about half of these calls.
The saddle valve. In older Boston housing — anything with a fridge fitted into a kitchen that predates plumbed refrigerators, which is most of the brownstone and triple-decker stock — the water line was very often teed off a nearby pipe with a saddle valve. These were never good and they close themselves over the years as the seat corrodes. If your ice slowed gradually over a couple of years, look under the sink or in the basement for one of these before condemning anything inside the appliance.
The fill tube, frozen. A partial fill leaves water sitting in the fill tube, which then freezes and blocks the next fill. You get an ice plug you can see at the back of the ice maker. Clearing it fixes the symptom for a week; the reason it under-filled is the actual fault.
The inlet valve. Electrically operated, it fails open or closed and it clogs. This is a routine repair.
Then the temperature
Ice makers do not run on a timer. They wait for the mould to reach a specific temperature — typically around 15°F at the thermostat — before they harvest. A freezer that is holding 20°F is keeping your food perfectly frozen and will never make ice.
So: put a thermometer in the freezer, not on the display. You want 0 to 5°F. If it is warmer than about 10°F, the ice maker is not broken, the freezer is not cold enough, and that is a completely different repair.
This is the diagnosis behind a large share of winter calls in this region, and it comes from a specific local habit.
The garage and basement problem, which is a real Boston pattern
A great many households here keep a second refrigerator in an unheated basement, a back porch, a mudroom or a detached garage — triple-deckers in Dorchester and Somerville, single-families in West Roxbury, Milton and Belmont, and essentially every house on the North Shore with a barn or an outbuilding.
Below about 38 to 40°F ambient, a conventional single-compressor refrigerator stops calling for cooling at all. The fresh-food compartment is already cold enough, so the thermostat never closes, so the compressor never runs, so the freezer slowly climbs — and the ice maker, which needs 15°F at the mould, stops first. It is the earliest warning that this is happening.
The machine reports nothing wrong because nothing is wrong with it. It is being asked to work outside its rated ambient range. A garage-ready model with a dual-thermostat or heater arrangement solves it. A new ice maker does not, and we will tell you that rather than fit one.
Then the harvest
If water arrives and the freezer is genuinely cold, the fault is mechanical or electrical in the ice maker itself: the mould heater that releases the cubes, the ejector motor and gears, the thermostat, or the module.
The signs are distinctive. Cubes formed but stuck fast in the mould is the mould heater. A grinding noise with no ejection is the gear train. A full mould of water that never freezes with a genuinely cold freezer points at the thermostat or module.
Modular ice makers are usually replaced as an assembly rather than repaired component by component, because the assembly is not expensive and the labour to rebuild one exceeds its value.
The water question, which differs across our footprint
Inside the MWRA area — most of Greater Boston, plus Cambridge on its own Fresh Pond supply — the water is soft, around one to two grains. Scale in an ice maker is therefore rarely the problem, whatever the internet says. What we find instead is fine sediment from century-old iron mains and building risers, sitting in the inlet screen.
On the North Shore and in the well-supplied towns at the edge of the footprint — Wellesley, Dover, Canton, Westwood, Dedham, Needham, and most of Essex County — the water is genuinely harder, and there scale is a real finding. Descaling on a routine, keeping the filter current and setting the machine's hardness option if it has one all pay for themselves.
Ice that tastes wrong
Not a fault, usually. Ice absorbs odours, and old ice absorbs a lot of them. Dump the bucket, wash it, and let it refill. If the taste returns within a week, replace the filter. If it persists after both, the problem is what is in the freezer, not what is making the ice.