A dehumidifier will stop collecting water if the coils are dirty or corroded. A faulty compressor or capacitor, damaged motor, low refrigerant, or loose screws can also stop your dehumidifier from collecting water. In low humidity (less than 30% RH), it’s completely normal for dehumidifiers to not collect water.
Like all appliances, dehumidifiers stop working after a while. In most cases, this means your dehumidifier will stop collecting or draining water.
This article is a one-stop guide on how to figure out the root cause of your dehumidifier not collecting water, and how to fix it.
11 Reasons Why Your Dehumidifier Is Not Collecting Water
Dehumidifiers start collecting water as soon as they’re turned on. Although it can take up to 12 hours to make a noticeable difference in humidity levels.
If the dehumidifier is too small, it can take days to dehumidify a room sufficiently.
Now, tank sizes range from 1 to 70 pint, but most tanks should fill in around 6-7 hours (except of course if you have a continuously draining model).
If your dehumidifier isn’t collecting water, the following reasons are all the possible environmental problems or system errors that could be causing it.
Which problem will apply to you will also depend on which type of dehumidifier you have in terms of compressor or desiccant. Where possible we’ve pointed out which problem applies to which type of dehumidifier (otherwise it’s all types!).
1. Low Humidity Or Temperature
This might seem obvious but we need to cover it. The relative humidity (RH) levels in the room need to ideally remain within 30 to 50% and between 40 and 90°F.
If the relative humidity is too low (below 30%) or it’s too cold (below 40°F), then most dehumidifiers won’t work. At the very least they won’t collect water, and in some cases will even switch off.
Unfortunately, there is no real solution to this problem. It’s best to clean and store your unit until the humidity and temperature rises.
Note: Some models don’t operate below 60 degrees so check your user manual (if you can) to see if your unit is okay to run.
2. Deflective Capacitor
If the RH is in the ideal range (30 to 50%) and the ambient temperature is not below 40 deg Fahrenheit (the point at which moisture will freeze on the cooling coil, damaging the unit), then your dehumidifier may be acting up because of a faulty capacitor.
It’s part of the compressor unit, and the dehumidifier needs it to properly circulate the refrigerant. Without it, it can’t absorb moisture.
You can use a multimeter on the Capacitance Measurement mode to detect if the capacitor is working or not.
Solution
Although you can get the capacitor checked with a technician to see if there is a chance of repair, it might not be productive in the long run. The deflection, i.e hard starting and shutting off after a while, will often happen again and stop the dehumidifier from working properly.
In this case, it’ better to replace the blown capacitor with a new, functioning one – or a new dehumidifier (which ever is cheaper)
3. Low Refrigerant
Refrigerant is a chemical substance used in condenser dehumidifiers. It absorbs the hot surrounding air and takes it over the cooling coil.
If the refrigerant levels are low, the warm moist air cannot condensate, which leaves the room humid and the dehumidifier unable to collect water.
To see if this is your problem, turn the dehumidifier off and disassemble it to locate the cooling coil. Normally, the coils are too cold to touch because of the refrigerant, but if there isn’t enough refrigerant, the coils won’t be cold.
Although it is normal for refrigerant levels to drop after use, this is usually a very small change.
It’s more likely for it to leak through the system. If you notice an abnormally fast or large drop in refrigerant, look over the unit to see if you can find the point of the leak.
Solution
To refill refrigerant in the dehumidifier:
- Take the valve cover off the machine and attach a filler pipe to the appliance.
- Fill in the refrigerant in small thrusts through the pipe.
- To protect the compressor from damage, it is essential that you ensure no excess air gets in the pipe or the system.
- After completion of the process, remove the pipe and place the outer case back.
If the refrigerant is leaking out of the dehumidifier, getting the unit fixed can get expensive. So in this scenario, it’s often better to invest in a new dehumidifier.
4. Faulty Humidistat
Dehumidifiers come with a built-in humidistat to measure the moisture levels in the air. This is important as it helps regulate the process and makes sure the humidity levels are kept within the set range.
If the sensor in the humidistat starts acting up, it won’t register the correct reading, and will stop the dehumidifier from working correctly. The easiest way to detect a faulty humidistat is using a multimeter.
Turn the dehumidifier off, and then connect the multimeter probe to the humidistat. The multimeter should display zero. Plug in the appliance and increase the humidistat setting until you get a clicking sound (which happens at the highest setting).
If the multimeter registers 24 volts, it means your humidistat is working fine. If the needle stays at 0V or deflects only slightly (not close to 24V), it means that you have a faulty humidistat.
Solution
Replace the sensor with a functional, new one to fix this problem. Although, if you only have a small portable unit it’s often easier to just get a whole new dehumidifier.
5. Dirty or Corroded Coils
A condenser dehumidifier has two separate sets of coils:
- Cooling coils, and
- Reheating coils.
The first set cools the air down and plays an important role in condensation, while the reheating coils help send the warm, dry air into the room.
These coils naturally corrode over time. Dirt and debris from the environment can also deposit on them. If the coils aren’t cleaned fairly regularly, corrosion and dust can prevent the condensation process from working efficiently, which stops the dehumidifier from collecting water.
Solution
- Disassemble the system and inspect the coils.
- If you have a dirty coil, use a handheld vacuum to clean off dust from the surface.
- Use a soft bristle brush for hardened deposits.
- Replace any corroded coils.
- Do not pour hot water over the coils.
Ideally, your dehumidifier coils should be cleaned at least every 3 weeks to keep them from getting dirty or corroded.
6. Frozen Coils
Frozen coils are particularly problematic for compressor dehumidifiers since they are designed for high ambient temperatures (i.e 60°F or higher). When compressor dehumidifiers are used in cold climates (i.e low temperatures), the condensed water cools down on the coils leading to frost.
The problem is usually made worse by issues in the fan or motor that prevent effective airflow.
Ice build-up can not only stop the dehumidifier from working, but it can also damage the motor, sensors, or other parts of the system.
Frost issues are easy to notice as the ice is visible from the outside. With this issue, the dehumidifier may also start blowing out cold air – If this is the case read this article on how to fix it.
Solution
- Turn the dehumidifier off and let the ice melt before using it again. It’s important to check over the whole unit to find and fix any possible damage.
- Clean the coil as outlined above, i.e., using a vacuum and a soft brush.
- Once the ice melts completely, plug the dehumidifier in, and check if all the other parts i.e motor, sensor, humidistat, fan, etc. are working fine.
If the temperature in your area is less than 60°F for most of the year then it’s better to use a desiccant dehumidifier as it’s better-suited to cold climates.
7. Broken Compressor
The compressor is important as it works with the refrigerant, pressurizes it, and converts it into vapors.
So, if the compressor breaks down, the refrigerant is unable to soak in enough moisture, and damp, cold air will be blown back into the room.
This problem is easy to identify as your room will feel colder than usual, and your dehumidifier will often make a clicking sound when turned on.
Solution
The only solution is to replace the compressor. That can be costly, so you might want to consider buying a new dehumidifier.
8. Blocked Fan
The fan rotates to draw in air. If anything blocks the rotation path, the fan won’t move, and the unit won’t have any air to dehumidify.
To check, unplug the dehumidifier and open it up. Gently try moving the fan manually with your hand. If it doesn’t turn freely and properly, then it’s blocked and needs maintenance for the dehumidifier to collect water.
If it moves smoothly, then there’s no blockage, and the problem is in some other part of the system (so keep reading!).
Solution
Fan blockages are usually because of dust or debris.
Clean the fan with a dry, soft cloth and move it manually to confirm that the blockage is removed. Do the same for the wheel if you have a desiccant dehumidifiers.
9. Faulty Fan Motor
The motor is a complicated component, and several things can go wrong with it. In a dehumidifier, a faulty motor will prevent the fan from rotating, and the unit will fail to draw the air in.
If there is a defect, the motor can also overheat. This causes the whole unit to heat up. So if the outside of the dehumidifier feels unusually hot when you touch it, it probably means you have a dysfunctional motor.
Solution
Replacing the motor is the only solution. Since purchasing a new motor is usually expensive and sometimes impossible as they aren’t easily available, do a cost-benefit analysis to see if it’s better to buy a new dehumidifier instead.
10. Loose Screws
If you notice a rattling noise coming from your dehumidifier every time it runs, the mounting screws may be loose.
If the screws are missing or loose, the fan’s rotation is limited, and the dehumidifier won’t draw in enough air to collect water.
Solution
Since each model of dehumidifier is built differently, you’ll need to check your user manual for an exact guide on where the screws are located.
Check every screw in the system and tighten them if loose.
11. Problem in the Circuit Board
What people often tend to overlook is an issue with the circuit board. A dehumidifier is an electrical device, and an uninterrupted current flow is always needed.
Every dehumidifier comes with a circuit board that connects each of its parts. If the power supply to all or just some parts of the system is damaged, it will impact the entire process – this includes the dehumidifier collecting water.
Solution
Control boards can be fixed, and replacing them is also easy on the pocket. These can usually be purchased from the manufacturer, so it’s best to contact your brand’s customer support to arrange the part or a technician.
Helpful Tips
Always empty your dehumifier
If the dehumidifier has an automatic drainage system, it will remove the water from the hose and continue to operate normally. However, if manual removal is required, the unit should automatically shut off once the bucket is full because of the float system – this is to prevent overflow.
Empty the bucket every 6-8 hours, or when the automatic shutoff kicks in.
Choosing your disposal method
The water from your dehumidifier can be emptied down the drain or in the toilet, but it’s more environmentally friendly to recycle the water in the garden.
Remember it’s important to empty the water regularly to help prevent rust or corrosion in the dehumidifier.
Dehumidifier water can contain contaminants and is not safe for drinking. But it’s a great alternative to tap water for gardening as it doesn’t contain chlorine so it’s suitable for plants.
So if you want to recycle the dehumidifier water, use it for gardening but refrain from using it as a potable source.
Plentiful Air has a complete guide to dehumidifiers that don’t need to be manually emptied available here.
