Why Is My Dehumidifier Blowing Hot Air

Dehumidifiers are essential to maintaining the comfort level of your home. A dehumidifier can lower humidity levels in the house, limiting the growth of mold and dust mites.

They can make your home feel cooler when things are hot and muggy. They may be set up in problematic rooms of your house like the basement game room or kitchen or they may serve the entire home.

However, they are appliances that can malfunction. Your dehumidifier may run hot or cold, but running hot is worse for a variety of reasons.

Why is my dehumidifier blowing hot air?

We’ll share some of the most common causes. See them below:

How hot is your home?

Before you assume there is a mechanical problem with the dehumidifier, consider the temperature of the environment around it. The dehumidifier may vent cooler air than the rest of the room thanks to the dehumidification process.

However, if the room is 100 degrees F, it isn’t unreasonable for the dehumidifier to be 100 degrees F while exhaust air is 80 to 90 degrees F. You can tell if the unit is working properly if it is actually reducing the humidity in the room and isn’t flashing warning lights.

Common warning lights on the dehumidifier include overheating, a full reservoir light and low/no refrigerant.

Is the dehumidifier set to dehumidify?

If the dehumidifier is in fan mode, it will blow hot air if the home is hot, too. After all, it isn’t set to cool off and dehumidify the air. In this case, you can solve the problem by turning on the dehumidifier.

In some cases, it would be due to the need to empty the water reservoir. If the reservoir is full, the unit may still move air but not dehumidify it. Empty the bucket, then reset the unit and see if it starts blowing cooler drier air.

Does the dehumidifier have refrigerant in it?

A dehumidifier relies on a cooling cook similar to those used in air conditioners. They require refrigerant to cool down the ring or surface that air passes over. Moisture in the air condenses on that surface and runs into the water reservoir.

If the dehumidifier is leaking refrigerant, the first sign you’ll have is ice forming on the dehumidifier. The refrigerant escaping dramatically cools off the air in that area. Once the refrigerant runs out, the dehumidifier surface can’t cool down.

Now it will be room temperature at best. If the compressor or motors are running long and hot, then the unit will be hot. Not all dehumidifiers have warning lights or error codes to tell you that it is out of refrigerant, overheating or both.

However, a lack of refrigerant will cause it to never turn off if it lacks the intelligence to shut down.
The solution is to turn off the dehumidifier. Then call a service person to fix the refrigerant leak and recharge the refrigerant.

Does the unit feel hot?

Suppose the room isn’t extremely hot. Is the dehumidifier hot? It contains a compressor to cool down the ring or surface that the air flows over. That can overheat if run too long. It also contains electrical components. These can short out or burn out at any time.

If the dehumidifier has a run-time indicator, check that. If it has been running for several hours and now feels hot, write down any error codes and then turn it off. Keep it off long enough to cool down.

Research the error codes in case they mean the unit is out of refrigerant or is suffering a mechanical problem. If the unit is telling you it has a mechanical problem, get it serviced.

If you’re reluctant to do that just yet, let it cool down, then plug it in, watch it run and see if the same error codes occur. If they do, turn it off to limit additional damage and call for service.

A dehumidifier can have electrical problems that cause it to overheat. This is actually more dangerous than a mechanical problem. A stressed compressor has to run for a while before it overheats, and if that happens, the unit will seize up.

If the unit is hot because capacitors in the unit are burning out, the unit could eventually get so hot that it catches fire or an electrical short inside it could trigger one. An electrical issue may explain why the unit heats up as soon as you turn it on, even though it has refrigerant.

You could try to locate the heat source by touch. For example, the motor housing being hot is more likely to be due to a mechanical issue than an electrical one.

A control board that is hot is more likely to be an electrical issue. And a malfunctioning control board may not give you the right error code.

Since dehumidifiers contain water and electricity, there is certainly plenty of potential for shorts caused by moisture. You should turn off the unit and unplug it while calling to have the unit serviced.

You could open up the unit after it is unplugged and try to troubleshoot the electrical issues, but most people lack the necessary skillset. Alternatively, you could replace the entire unit.

After all, if it is experiencing shorts in the wiring or control board, other parts may be burned out. And dehumidifiers are typically so cheap that it costs as much to replace components as it would buy a new unit.

Could the dehumidifier be hot because of a lack of airflow?

An air conditioner can get hot because it lacks sufficient airflow to vent waste heat. In the case of a dehumidifier, the outgoing air is colder than the incoming air.

If the dehumidifier doesn’t have adequate airflow, the air around the dehumidifier will get colder and colder. This can cause moisture on the dehumidifier to the freezer.

However, the moisture on the dehumidifier can freeze if the room temperature isn’t very high above the operating temperature of the unit, too. For example, most humidifiers are prone to freezing up if the air temperature is less than 50 degrees F.

However, the dehumidifier motor can get hot if it lacks sufficient incoming air. The main causes of this are a blocked air vent or a very dirty air filter. If the incoming air vent is blocked by furniture or the wall, simply move the unit.

If the air filter is clogged, replace it. Then check the unit’s temperature. If it remains hot, there is a mechanical issue that needs to be addressed. And the lack of airflow could have caused the unit to work so hard that components wore out.

Now the friction of them rubbing together is generating extra heat. This calls for service.