How to Safely Use Dehumidifier?

China dehumidifier factory

Content Category

When you own a dehumidifier, should know what to pay attention to when using it, and what to do when there is a problem.

Probably the following knowledge will help you.

How to Use Dehumidifier Safely?

1. Read the instruction manual carefully

Operate according to the regulations, and don’t press the buttons on the remote control and the display panel randomly.

2. Use dedicated power supply

Meanwhile, pay attention to the voltage of the power supply and the machine are consistent. Don’t be afraid of trouble after usage, try to unplug the power supply.

3. Fix the dehumidifier in a flat place

To ensure smooth airflow, should be no obstacles surroundings, so as not to affect the air circulation.

4. Use dehumidifier in well-sealed premises

Such as doors and windows should be closed, and no indoor appliances which can produce water vapor.

Because dehumidifier uses internal air circulation for dehumidification and moisture control, if the sealing property is not good, will affect its dehumidification effect, extending the working time of dehumidifier and increasing energy consumption.

5. Dehumidifier shouldn’t use close to the heat source

When surrounding temperature exceeds 40 ℃, pressure in the dehumidifier system will increase so that the compressor overloads, then the overload protector may cut off the circuit, the compressor will stop working.

The best temperature range of dehumidifier usage is from 15 ℃ to 40 ℃ normally.

6. Appropriate Humidty

If the air humidity is below 30%, it will be too dry and make people uncomfortable, so the humidity value of the dehumidifier should be set at 40% or more.

7. After moving the dehumidifier, sit 4-6 hours before re-switch it

Because the compressor system contains refrigerants, which need 4-6 hours to recover.

8. Tilt angle less than 45 degrees when moving the dehumidifier

To avoid inverted or horizontal placement causing refrigerant backflow and compressor internal shock spring decoupling, so that the compressor has a heavy noise and can’t use normally; also to prevent excessive vibration, so as not to cause pipeline broken, damage the machine.

9. Working sound

When Dehumidifier is in operation, if you hear the sound of the metal collision or other strange sounds, should stop the dehumidifier and check, especially to check whether the centrifugal air leaves and pot shell impact each other and whether the fasteners are loose.

10. Unplug and clean 

When the dehumidifier stops using for a long time, should unplug and clean the entire machine. Volatile oil, thinner, detergent may cause harm to the dehumidifier, please do not use.

Wipe the surface and filter with a clean cloth dampened with warm water. The cleaning of internal parts needs to find a professional after-sales and maintenance company.

11. Condenser and evaporator should clean frequently

So as not to cause the fins blocked, affecting the air intake and outlet.

12. Pull out the water timely

If you don’t empty the water tank in time. Then the water may overflow, and long-term standing water will accumulate a lot of bacteria and mold. Because this water is separated from the dehumidification system, there are usually many bacteria and viruses in it, especially in the case of covid-19, you must pay special attention.

Water tank of dehumidifier

Pull Out the Water

13. Regularly clean the filter

Noted that when cleaning the casing, use a damp cloth to gently wipe; don’t directly splash water to clean up, which will damage the electrical insulation.

If the casing surface has adhesives, soap and water can be used to clean, forbid using gasoline, petroleum spirits, solvents or spray insecticide spray cleaning, to avoid the stripping paint or discoloration.

Don’t use a thin rod or wire to touch the interior machine, which will bring malfunction or danger.

14. Don’t disassemble Manually

Some dehumidifier manufacturers use digital microcomputer control, due to its precise control of the original device, non-professionals don’t disassemble randomly.

15. Defrosting

Home Dehumidifier will frost when used in a low-temperature environment, then some dehumidifiers have automatic defrost function, and if the product is without defrosting function, you need to do it yourself to defrost.

That is, disconnect the power so that it melts itself.

16. Don’t slipe randomly

For dehumidifiers with casters for sliding, please do not slide on carpets or surfaces with obstacles.

Avoid the water in the water tank from shaking from side to side and overflowing from the water tank and the dirt on the ground wraps around the casters to make it difficult to slide smoothly.

Don’t slipe randomly

17. Restart the dehumidifier for more than 3 minutes

The older dehumidifier shouldn’t restart within 3 minutes after it is shut down, otherwise the compressor will be burnt out easily.

The new-model dehumidifier is equipped with a circuit that prevents it from restarting within 3 minutes. Even if it is restarted within 3 minutes, the compressor will not work.

18. Don’t spray insecticides ont0 dehumidifier

When the dehumidifier is in operation, do not spray insecticides or volatile liquids on it, so as to avoid leakage and cause a fire.

19. Dehumidifier voltage

When the power supply voltage exceeds the rated working voltage (max 240V), had better stop the dehumidifier to ensure safety.

When dehumidifier on operation, if find the power supply voltage is too low, you must immediately cut off the power and stop using, otherwise the compressor will be damaged.

Why Dehumidifier Not Collect Water?

1.  Humidity setting unreasonable

Dehumidifier humidity value should be set in a reasonable range, such as home dehumidifier: 50-60%, commercial dehumidifier 40-60%; industrial dehumidifier 35-50%. If the dehumidifier sets the humidity value higher than the current humidity.

In automatic mode, the dehumidifier compressor will not work. In this case, you see as if it was working, but in fact only the fan is working and the compressor is not working at all. We thought the dehumidifier seems work normally, but actually is not.

That is the common reason why the dehumidifier is working but has no water collected.

2. The ambient air is too dry

When Industrial Dehumidifier in RH(relative humidity) ≤ 35%, home dehumidifier in RH ≤ 45%. Normally in the dry season (autumn and winter), the air humidity is low, no collected water is a normal phenomenon.

Because the water percentage in the air is very little, in this period if we set the humidity value ≤35%(for industrial dehumidifier), home dehumidifier set RH ≤ 45%, although the dehumidifier works for a long time , but with no collecting any water or just a little.

So we should pay attention not to set industrial dehumidifier ≤35%, home dehumidifier not set ≤ 45%, otherwise will seriously affect the lifespan of the dehumidifier.

3. The ambient temperature is too low

When working dehumidifier in ambient temperature below 18℃ began to frost, when working temperature <10 ℃ is easy to ice, so you have to wait longer.

In this situation, dehumidifier work half an hour (or even longer) without collecting water is very common.

Ambient Temperature is Too Low

4. The ambient temperature is too high

Conventional dehumidifier noted in the manual and the machine temperature range of 5-38 ℃, some said 5-35 ℃, which means if the ambient temperature is more than 38 ℃, the dehumidifier will automatically start the protection device, at this time the dehumidifier doesn’t collect water, also can’t work properly.

So we recommended using the dehumidifier in the ambient temperature range of 5-38 ℃ normally.

5. Overload protection

If the dehumidifier working a long time without stopping will automatically start the protection device, because of overload work and overheating.

Thus, the dehumidifier does not collect water. Usually, when the temperature exceeds 38 ℃, dehumidifier will start automatically protection device, just the fan work, not the dehumidification.

6. Air intake or outlet is blocked

Dehumidifier depends on air intake & outlet, and constantly circulating to deal with the moisture in the air. If air intake or outlet is blocked will lead to dehumidifiers not collecting water, because the air can’t circulate for processing, but also will seriously affect the lifespan of the dehumidifier.

Air intake and outlet must space about 500-2000mm appropriately.

7. Too much dust

Dehumidifier regularly cleans dust is an important work we must do in daily life, especially in the high dust industrial production environment of industrial dehumidifier, every 3-7 days should clean dust. Once a month to clean household dehumidifier is appropriate.

Cleaning method: remove the filter of air intake, use water or air gun cleaning.If the hydrophilic aluminum foil with the dust must clean as well. Too much dust can easily block air intake, also will result in dehumidifier water absorbed by dust, which will cause no water discharging.

8. Unstable voltage

Compressor will automatically stop working if the power supply voltage is unstable, thus leading to no discharging water. Dehumidifier for a long time in the power supply voltage instability environment will seriously shorten the lifespan of the dehumidifier.

9. Motor fan issue

When the humidity is set in the normal range, but you don’t feel any air flowing out of the machine, then it may be a fan problem.

It may not be running because the fan is blocked or stuck, usually with a buzzing sound, and needs to be removed as an obstruction or replaced with a new fan.

10. Capacitor issue

If the new compressor can’t run normally and doesn’t collect water, sometimes is the capacitor issue.

In the test of starting capacitor of the compressor (use a multimeter), if it can’t charge or discharge, indicating that the compressor capacitor has been damaged and needs to replace.

There is another capacitor for the fan motor as well. If the brand new fan motor can’t work, probably is the capacitor issue, need to replace a new one, it’s cheap price, no worry.

Digital multimeter testing

Capacitor Testing

11. Refrigerant leakage

Normally we use R290 or R410a refrigerant for dehumidifiers,  the refrigerant leakage will result in no water coming out. Refrigerant leakage is a common reason, need skilled service company staff for confirmation after testing or inspection, must be repaired before use.

12. Electric board issue

Sometimes if all other parts are working normally, the issue probably comes from the electric board.

The electric board is a fragile part, so please find a professional repair company for checking and repairments.

Electric Board

13. Compressor failure

After several years of use (depending on the frequency of use. Household dehumidifiers are usually about 5 years, industrial dehumidifiers are usually about 3 years), the compressor is prone to failure.

There are two kinds of failures: compressor aging internal scurrying gas and compressor burn or short circuit tripping. In these situations we have to replace the compressor, actually, maintenance costs are relatively high.


We hope that through the above information, you can use the dehumidifier correctly and find out why the dehumidifier does not collect water. Maybe you can solve the problem by yourself.
That’s really great.

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About Author

Vic Cheung
Vic Cheung

Hi, I'm Vic! Start working in HVACR field since 2008, our main products included: air conditioning, cold room refrigeration system, water chiller, ice machine, commercial dehydrator, dehumidifier, heat pump, electric motor, and all accessories. Since joined China Speedway Group in 2012, I worked in here more than 10 years, as the general manager of export department, we have established 50+ agent in different countries and areas.
As our experience and strong technical support, we can solve your issue once you have, and our chief engineer has worked in HVACR field since 1997. I am so proud of our knowlege is more and more popular not only for engineer, and for HVACR business new comer, DIY lovers. Hope you are enjoying our articles, if any question or comments just welcome to send me marketing at

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