dehumidifier not working

What to do when your dehumidifier doesn't work?

Humidity control prevents all sorts of problems in commercial, residential, or industrial settings. It is a common strategy where musty odors, water damage, plant diseases, and condensation damage may occur due to humidity build-up.  Dehumidifier  Help regulate indoor humidity, reduce the growth of moisture and mold, improve air quality, and enhance living comfort.

However, just like any other appliance, prolonged use or lack of proper maintenance can lead to failure. This does not mean that the dehumidifier is defective, but rather that long-term use can cause parts to wear out and build up, increasing the likelihood of failure.You can imagine the frustration when you switch on the dehumidifier and it fails to work.

There are several potential reasons why the dehumidifier is not working, but there is a diagnosis and remedy for each of them. Let’s deep dive into the common causes and the diagnosis steps.

Common Problems with the Dehumidifier

Blocked Filter

The effectiveness of the dehumidifier function largely depends on the quality of airflow. If the air cannot freely reach the coils and leave, the indoor humidity will largely remain unchanged.

Humidity Sensor/Humidistat Malfunction

Units with electronic control have a humidity sensor while those without this capability have a humidistat. If these components malfunction, the device can stay off.

Fan Motor Failure

The fan motor in the dehumidifier helps get rid of moisture from the air by circulating air on the evaporator coils. It could fail due to overheating and bearing malfunction.

Sensors failure

The dehumidifier has a humidity and temperature sensor. These sensors check the humidity and ambient air temperature respectively. They activate the dehumidifier when the temperature and humidity reach a certain point.

Water Tank Full

The dehumidifier is designed to sense the level of the water in the reservoir tank. It will shut down when the tank is full to prevent overflow problems.

Control Board Issues

Electronic dehumidifiers feature an electronic control board (PCB), which controls the compressor and several other functions of the unit. It could be the reason why these components don’t start at all.

Diagnosing Dehumidifier Issues

Here are steps you can take to identify the dehumidifier problem fast:

1. Perform initial checks and verifications

The first check for a dehumidifier that won’t work is the power connection. Go to the main electrical service panel and check if the unit is turned ON.

Check the fuse or circuit breaker dedicated to the dehumidifier for any tripping or malfunction.

Verify also that the controls for the unit are ON.

Finally, ensure that the relative humidity setting for the dehumidifier is at 50-60%.

If all these are okay but the unit still doesn’t work, you need to inspect the individual components of the dehumidifier.

2. Inspect the dehumidifier components

For easier inspection, start with the ones that are easier to access. Inspect the filter for any debris or debris. If necessary, clean or replace the filter and this could bring back the effectiveness and efficiency of the dehumidifier.

Other components that need inspection are the fan, the drainage system, and the coils (for the condenser and evaporator). If the unit has frozen up, you want to check the fan for any malfunction.

For the drainage system, check for blockage along the drain line. Ensure that the bucket is well positioned. If the bucket is not full, you need to check the bucket switch.

3. Perform diagnostic tests

Diagnostic tests can be easy with the right expertise and tools. If you feel you cannot safely perform the tests, consider asking for professional help.

The most important diagnostic tests are on the power outlet, power cord, and essential components of the dehumidifier – humidity sensor, compressor, bucket switch, and fan motor. These tests typically involve basic tools such as the multi-meter and screwdriver. As the norm, wear your PPEs while performing these tests.

If the unit is still nonfunctional after testing/inspecting and fixing the issues up to this point, there are other potential causes to investigate.

4. Consider other factors

Apart from the issues related to the dehumidifier components, failure to work may also be attributed to external factors. Chief among them are the humidity levels in the room.

It’s important to note that the unit may not activate if the humidity setting is too high compared to the true humidity of the room. It doesn’t get the prompt to dehumidify the air.

We always insist on the right sizing for the crawl space dehumidifiers. Using the right unit capacity for the room size is worthwhile because if the equipment is too small for a room, its effectiveness may be negligible.

The same applies to a dehumidifier that is too large – the on-and-off cycles can be a nuisance and energy-wasting.

5. Consult the Manufacturer’s Guide

Still not enjoying the services of your dehumidifier? You can get valuable troubleshooting help from the user manual or manufacturer’s guide.

The good thing with these resources is that they are model-specific. Some of them have solutions to various error codes that come from the machine. For instance, page 10 of the user manual for Aloraircrawlspace Sentinel HD35P gives handy troubleshooting guidelines.


Want to keep the dehumidifier working?

The dehumidifier requires regular maintenance to remain in good working condition. Alongside the usual maintenance, ensure that no dust and debris accumulate around the dehumidifier.  

It is also important to use the unit in moderation. Running the dehumidifier 24/7 may be unnecessary and could even harm it. Every model has runtime and capacity limits. If you can to keep it within these limits, chances of it serving you to its complete lifespan are high.

Aloraircrawlspace has exciting modern dehumidifier models of different capacities – there is a solution for every application.


If your dehumidifier is no longer working, there are several steps you can take to pinpoint the possible cause. Systematic inspection and tests will most likely reveal where the problem lies. That said, a well-used and maintained dehumidifier can perform excellently for many years.

Aloracrawlspcae dehumidifiers are among the most trusted in the market. Since 2012, we have been at the forefront of providing innovative products and services to our residential and commercial customers. We are renowned for the best humidity control solutions, particularly through the crawl space dehumidifier.

For more information about our rich blend of dehumidifiers and general dehumidifier health, contact our representative today.