Dehumidifiers ·

What is the Dehumidifier F0 Code?

One of the most common problems we’ve seen in the dehumidifier market, no matter what brand you own, is the dreaded F0 malfunction code. 

In this article, we’re going to break down what the F0 code means, some tips on how to resolve it, and what we can do for you if you see an F0 malfunction code on TOSOT your dehumidifier.

To understand what the F0 code means, we first need an idea of how a dehumidifier works.

How Does a Dehumidifier Work?

For the sake of simplicity, imagine that your TOSOT dehumidifier works kind of like a vacuum cleaner.

A vacuum cleaner uses a motor to spin a fan to suck in air, remove dust, dirt, and debris from that air, and then blow air back out of the vacuum.

In a similar way, a dehumidifier uses a motor to spin a fan to suck in humid air, remove moisture, and then blow the dry, heated air back into the room.

To remove humidity from the air, moist air passes over a refrigerated cooling coil. Moisture from the air collects on the copper cooling coils the same way that water collects on the outside of an iced beverage on a hot day: through condensation.

As water condenses on the refrigerated coils it drips off of the coils and is collected in the drain bucket of your dehumidifier. (If you have the continuous gravity drain connected to your unit, collected water will bypass the drain bucket and flow directly out the gravity-fed hose.) 

If you have a unit with an internal pump, water will collect in the bucket and then automatically be pumped out of the bucket once the bucket is nearly full.

While water collects in the drain bucket, the now moisture-free air is reheated so it can be blown back into your room.

Now that we’ve discussed how a dehumidifier works, let’s move onto the F0 malfunction code.


What does the F0 Code Mean?

All TOSOT dehumidifiers are equipped with a self-diagnosis function which is displayed on the control panel.

This self-diagnosis function also lets you tell customer service what is going on with your unit so we can help get your dehumidifier working again.

In some cases, solving the malfunction code is as simple as removing and cleaning the filter on your unit, or unplugging the unit for a few minutes and plugging it back in. 

The malfunction code F0 means your dehumidifier is low on refrigerant, typically caused by a leak in the enclosed refrigerant system. 

When the copper cooling coils lack refrigerant they do not cool down, so when moist air passes over the cooling coils, it does not form the condensation that drips down into the drain bucket.

This means your dehumidifier is pretty much working as a glorified box fan.

In order to remove this error, you would have to find the leak, safely remove all remaining refrigerant in the unit, repair the leak, and then refill the system with refrigerant.

This is not a procedure that we recommend, nor do we take any responsibility for telling you this information. If you keep reading we will help you solve this problem, but for right now we just want to provide you with some background information. Moving on!

Since the refrigerant leakage progresses slowly and won’t immediately stop the machine from functioning, some of our competitors have configured their dehumidifiers to keep working even after the F0 error code appears in order to reduce return requests from customers.

Although your dehumidifier is still “technically” working in this case, it will have a much lower dehumidification performance, will waste electricity, and may have an increased risk of serious malfunction or damage. 

At TOSOT, we are a responsible and reliable brand with more than 20 years of experience in dehumidifier and air conditioner manufacturing. We value your safety and designed our dehumidifier setting to immediately stop working after the F0 error shows.

We know this can be a little annoying for you, but we do it out of love because your safety is our top priority. Our team all uses TOSOT appliances in our own homes, so we would never sell you anything that we consider unsafe or could waste your hard-earned money. We’re all in the same boat here.


How to Solve the F0 Code

First off, we don’t recommend you disassemble the unit and start trying to Macgyver your dehumidifier back to health.

We’ve noticed a few self-proclaimed technicians offering “guides'' or “hacks” on how to solve F0 code issues. These guides suggest you disassemble the unit, remove sensors, cut wires, and do other potentially hazardous things to get your unit working again.

Although these guides may technically work, they do void the warranty of your unit and put your unit at a greater risk for fire or electrical damage. If you have an F0 code please don’t try to DIY your way back into a working dehumidifier. We have a few much better, much safer ideas.

If you receive an F0 Malfunction Code on your dehumidifier, here are six steps you can try right now to get your dehumidifier running again before contacting customer support:

  1. Make sure the ambient temperature in the room is between 41-90 °F
  2. Ensure the outlet voltage your dehumidifier is plugged into is 115V±10% by using a multimeter
  3. Reset the wall outlet at the circuit breaker, usually located in your basement, on the side of your house, or in a utility closet
  4. Try a different wall outlet, preferably an outlet that uses a different circuit
  5. Remove and clean the filter with warm, soapy water. Let the filter dry completely before reinserting it into the dehumidifier
  6. Unplug the unit for 20 minutes and plug it in again to see if the code still appears. This may reset the internal computer and remove the F0 code

If those don’t work, read on to see what TOSOT can do to solve your F0 malfunction code. 


How Will TOSOT Help You with an F0 Code?

If you purchased a TOSOT dehumidifier and you receive the F0 malfunction code, we are here to support you.

Although we place a great deal of emphasis on quality control, sometimes even the best products may malfunction.

It’s difficult to avoid accidents happening when products are shipped halfway across the world, handled rougher than we’d like by carriers like UPS and FedEx, and then used in a variety of environmental scenarios.

Each person will put different levels of care into their dehumidifier which can also affect if a malfunction arises.

If you have received an F0 malfunction code on your TOSOT dehumidifier, and you have already tried the six steps above, send an email to and a member of our support team will be in touch to confirm some details with you.

We want to get you a working replacement unit as soon as possible!



So there you have it, a complete guide to how your dehumidifier works, what the F0 code means, how to solve the issues, and what we can do to get your dehumidifier working again. 


If you have any other questions about the F0 code, please send an email to and a member of our team will be happy to answer them for you.


@Paul Romney – That is true, but according to our engineering team it would take several years for verdigris to form and affect the quality of the sensor.

TOSOT Support

@Dee – glad to hear it!

TOSOT Support

I cleaned my air filter and unplugged for a while and now it seems to work ok no F0 code


You don’t mention the possibility that the F0 fault arises from the formation of verdigris inside the sensor. This is something that can be fixed by cleaning the sensor.

Paul Romney

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