Why is my dehumidifier not collecting water?

A dehumidifier that is running but not collecting water is usually not broken. It is sitting in a room that is outside the condition its own capacity label was measured at. Here is the order the checks belong in, the two that look like a fault and are not, and the one figure no maker publishes.

One machine, three temperatures, one axis

There are three different temperatures in play, and all three are published. They are just not on the same page. One is the point the capacity label is measured at. One is the window the unit is said to run in. One is the point below which the same maker guidance says the performance you get is not the performance you paid for.

This is why the same machine can be "not working" in one house and fine in the next. The capacity cells themselves come from the sizing table, which is covered on the dehumidifier calculator and the basement sizing page; this page is about what to check when a unit you already own is not delivering them.

The order the checks belong in

Almost every troubleshooting list is a flat set of steps, which is why so many of them send people to the wrong part. "It is not collecting water" is three different claims, and each one has a different first check. Start with the row that matches what you are actually seeing, not the row at the top of somebody's list. The order is the same whatever the badge on the front — a GE unit or any other portable is measured to the same federal test condition.

The rest of this page takes the rows in the order a machine normally fails them: the coil first, because it is the one that looks like a breakdown, then the setting, then the water you cannot see, then the time it takes.

Frost on the coil is the one that looks like a fault

When the evaporator coil runs below freezing, moisture in the air freezes onto it instead of draining into the tank. The coil then ices over, air cannot pass through it, and the machine produces nothing while the fan keeps turning. It reads exactly like a dead compressor.

This is not a theory invented to explain a fault. It is written into the US test procedure itself, in the discussion of why the test is set up the way it is.

The practical reading is that frost is a symptom of the room, not of the machine. It is the same finding as the temperature chart above, arriving from the other direction.

That makes the type of machine a branch in the decision rather than a footnote to it. Above the rating temperature a condensing unit is the right tool and the pint figure is the axis that matters. Below it the pint figure is the wrong axis altogether, because the problem is the coil rather than the size of it — and the published guidance points to a unit specified for low temperatures instead. The capacity page covers the same split from the sizing side.

The setting, and why "no water" can mean "no work to do"

A dehumidifier with a humidistat is a thermostat for moisture. Set it at or above the reading the room already has and the compressor will not run, because the room is already at or below the target. Nothing is broken; the machine has been told not to work.

The published default settings are worth knowing, because they are lower than most people expect. One maker's support guidance describes a typical set as a bedroom setting of 55%, a basement setting of 45%, and a continuous mode that removes moisture above roughly 15%. It then states the consequence plainly: if the relative humidity is below or close to the minimum setting, water will not collect in the bucket or the drain hose.

So the cheapest check on this page is a hygrometer reading taken with the unit switched off, compared against the number on the unit's dial. If the room reads 48% and the dial is set at 50%, the machine is doing precisely what it was told. Turn it to continuous and the picture changes within the hour.

When the water is leaving and you cannot see it

A gravity drain hose is the most common reason a working machine looks like a dead one. The water goes down the hose instead of into the bucket, and an empty bucket is exactly what a correctly draining unit is supposed to look like.

The failure modes are all mechanical and all visible. A hose with a kink in it, or one that runs uphill before it drops, holds water in the line and backs the unit up. Published guidance is specific about the fall: a hose used as a gravity drain has to drop from the back of the unit down into a proper drain. Where a unit has an internal pump, the same guidance says to disable the pump until the machine's operation is confirmed on its own.

The check that settles it is the one the guidance recommends: take the hose off and let the unit use its own bucket for an hour. If water appears, the machine was never the problem. If it does not, you have eliminated the hose in one step and the rows above are where to look next.

How long before water should appear

This is the row that produces the most false alarms, and it is the one almost no product page puts a number on. A dehumidifier does not produce a visible amount of water in the first few minutes. It has to bring the coil down to temperature, and then the water has to condense and drip.

The published figure, from the same maker support guidance quoted above, is that depending on the conditions it may take an hour before moisture starts to collect, and that a brand new unit set up for the first time may take considerably longer. The same guidance gives the reset procedure: unplug the unit for three minutes, plug it back in, and set it to the lowest setting or continuous before judging it. The three-minute delay is not arbitrary — maker manuals state that the compressor circuit has an automatic three-minute delayed start if the unit is switched off and on quickly, to protect it.

What "collecting water" should look like in gallons

Pints per day is a rate, and a rate is hard to hold against a bucket. Eight US pints make a US gallon, so the published cells convert into a daily volume you can picture. The cells are the chart's; the division is ours.

A 50-pint unit is therefore a six-and-a-quarter-gallon-a-day machine at the rating condition — a bucket you would notice filling. But that figure is fixed at 65 °F and 60% relative humidity, and this is where the published material stops being useful: the maker guidance says performance is reduced below 65 °F, and the test procedure says units in service may meet anything from about 55 °F to 80 °F, but none of the documents we read puts a number on how much output is lost per degree. There is no published curve. So there is no honest way to say "a 50-pint unit is a 30-pint unit at 55 °F", and we are not going to invent one. What can be said is the direction, and the direction is down.

What this page does not cover

• A unit that never powers on at all. That is a power or switch fault rather than a water one, and the checks above will not find it. The four states this complaint can be, and which one you are in, are sorted on dehumidifier not working.
• A compressor that has failed or lost its refrigerant. The signature is the same — fan turning, no water — and the answer is service, not troubleshooting. The three-minute compressor delay described above is also easy to mistake for a dead compressor if you switch the unit off and straight back on.
• Sizing the unit in the first place. That is a different question with its own published table, covered on the calculator and on the pints page.
• Water arriving through a wall or a floor. No setting and no size of portable unit wins that argument. A machine that runs continuously and never catches up is describing a drainage problem, not a capacity one.

Questions this page answers

Why is my dehumidifier not collecting water?

Most often because the room is outside the condition the capacity label was measured at. Capacity is water removed per 24 hours at a fixed test ambient, and for a portable unit that ambient is 65 degrees Fahrenheit and 60 percent relative humidity. Published maker guidance gives the operating window as above 41 degrees and below 96 degrees and puts best performance above 65 degrees, so a room below that is inside the window the unit is sold for and outside the condition its number describes.

What temperature does a dehumidifier stop collecting water?

Published maker guidance gives the window as above 41 degrees Fahrenheit and below 96 degrees, with best performance above 65 degrees, and states that below the ideal figure the unit still runs and the amount of moisture pulled from the air is reduced. The same guidance says not to run the appliance while the room is outside the required range at all. So there is a floor below which it should not be run, and above that floor a band in which it runs and collects less than its label.

My dehumidifier runs but the bucket is empty. Is it broken?

Not necessarily, and there are four ordinary explanations before a fault. The room may be below the condition the label was measured at; the humidistat may be set at or below the room's own reading, which leaves the unit no work; the unit may be in a defrost cycle, which switches the compressor off; or a drain hose may be taking the water where you cannot see it. The check that separates the last one from the rest is to remove the hose and let the unit use its own bucket for an hour.

Why does my dehumidifier keep going into defrost?

Because the evaporator coil is cold enough for moisture to freeze onto it. The US test procedure's own discussion describes frost build-up on the evaporator coils as reducing performance and as triggering periods of defrost during which the compressor shuts off, and it concludes that defrost operation is uncharacteristic of typical operation at the 65 degree test condition. In other words, repeated defrost is a sign that the space is running below the condition the unit was rated at, not a sign that the unit has failed.

What should I set my dehumidifier to?

The published defaults are lower than most people expect. One maker's support guidance describes a typical set as a bedroom setting of 55 percent, a basement setting of 45 percent, and a continuous mode that removes moisture above roughly 15 percent. It states the consequence directly: if the relative humidity is below or close to the minimum setting, water will not collect in the bucket or the drain hose. Read the room with a hygrometer, unit off, and compare it with the dial before concluding anything.

How long does a new dehumidifier take to start collecting water?

Longer than a first impression suggests. Published maker guidance is that depending on the conditions it may take an hour before moisture starts to collect, and that a new unit set up for the first time may take considerably longer. The same guidance gives the reset procedure: unplug the unit for three minutes, plug it back in, and set it to the lowest setting or continuous before judging it.

Which kind of dehumidifier should I get for my basement?

It depends on the temperature the basement runs at, because the failure described on this page is a property of the condensing coil. A basement that stays above roughly 65 degrees takes a standard refrigerant unit and the published sizing cells apply. A basement that runs cold is where frost and defrost cycles start, and the published guidance for a cold space is a model specified for low temperatures rather than a larger pint figure. Size it from the cells on the calculator, then check the temperature before you choose the type.

How much water should a dehumidifier collect in a day?

At the rating condition, the published cells convert to a volume you can picture. Eight US pints make a US gallon, so 20 to 30 pints a day is 2.5 to 3.75 gallons, 25 to 40 pints is 3.13 to 5 gallons, and 30 to 50 pints is 3.75 to 6.25 gallons. The division is ours; the pint cells are the published sizing table's. Below 65 degrees the maker guidance says output is reduced, and none of the documents we read puts a figure on how much is lost per degree.

Why is my dehumidifier collecting less water than it used to?

Because the number on the box is fixed to one condition and the room is not. Capacity is measured at 65 degrees Fahrenheit and 60 percent relative humidity, and published maker guidance says output is reduced below 65 degrees. A space that has cooled since the summer gives up less moisture to the same machine, and repeated defrost cycles cut it further. The unit has not necessarily lost capacity; the condition it is measured at has changed.

Does a dehumidifier collect water in a cold basement?

It runs, but it collects less, and below the floor it should not be run at all. Published maker guidance gives the operating window as above 41 degrees Fahrenheit and below 96 degrees, with best performance above 65 degrees. Between 41 and 65 the unit still runs and pulls less than its label. In a cold space the coil is also where frost starts, which triggers defrost and cuts output again. For a basement that stays cold, the published guidance is a model specified for low temperatures rather than a larger pint figure.

Why is my dehumidifier not collecting water on continuous mode?

Continuous mode does not mean it collects from any air. It removes moisture above roughly 15 percent relative humidity, which is the floor of the setting range, not a guarantee of output. Published maker guidance states that if the room's relative humidity is below or close to the minimum setting, water will not collect in the bucket or the drain hose. A room that is already dry, or cold enough that the coil frosts, leaves continuous mode running with nothing to show.

Where these numbers come from

The fixed test ambient of 65 °F dry-bulb and 60% relative humidity for a portable unit, the 55 °F to 80 °F range a unit may meet in service, the 62 °F pre-stabilisation floor, and the description of frost on the evaporator coil cutting performance and triggering defrost are all from the US Department of Energy's dehumidifier test procedure and the rulemaking discussion published with it; the underlying procedure is 10 CFR 430 Appendix X1. The operating window of above 41 °F and below 96 °F, the note that performance is reduced below 65 °F, the typical humidistat defaults, the drain-hose requirements, the reset procedure and the settling time are from published maker support and manual documentation, read from two separate manufacturers whose figures agree. The capacity cells in the gallons table are the published ENERGY STAR sizing table, on the current rating basis. The single-axis arrangement of the three temperatures, the ordering of the checks, the conversion from pints to gallons, and the note that no published loss curve exists are our own working and are labelled as such. Nothing on this page is a test result, and no number here was estimated.