Dehumidifiers are usually very reliable products; however, when they do fail they can be a nightmare to repair. One of the most common problems with dehumidifiers is their tendency to freeze over, which stops air from being dehumidified, rendering the product useless. However, this is a fairly easy problem to fix and can oftentimes be carried out as a DIY job.
How Do I Know My Dehumidifier Has Frozen Over?
Dehumidifiers act like a refrigeration appliance; however, rather than remaining cold itself to freeze other things, it only acts to keep its evaporator coil mildly cool.
To do this, the dehumidifier reduces the coil to a temperature that is slightly below the 'dew point', which is the point where humidity in the air causes liquid to condense. This process happens naturally and can be identified by the presence of 'sweat' beads on the unit's evaporator.
If the evaporator coil is frosting over, there will be no condensation present on the evaporator unit as the temperature will not have reached near to the dew point. This means the moisture will remain solidified as frost which can act as a blockage against any additional air dehumidification.
What Causes This Problem?
The most common cause of this problem is an ambient temperature that is far too cool for dehumidification to occur naturally. All units will come with a manufacturer's guide that outlines the operating temperatures for these components. Typically, dehumidifiers cannot be used when the room temperature drops below 70°F or 65°F, depending on the humidity level in the room. For applications that demand such operating temperatures, there are special units available on the market known as 'basement dehumidifiers'.
If you're operating your dehumidifier within the recommended temperatures and are still experiencing a problem, then it's likely down to one of the following:
- Faulty/broken fan motor.
- Air blockage within the evaporator, condenser or filter.
- Faulty de-icer switch.
- Low supply of refrigerant gas in the unit.
To determine which one of the above problems have caused the frosting, you'll have to do a bit of investigation.
How Do I Know Where the Problem Lies?
Depending on the severity of the problem, many dehumidifiers can be diagnosed and repaired as a DIY job. This saves you the time, money and hassle it takes to call out a contractor to carry out the work for you. However, before you jump right in, you'll need to find out where the problem lies.
Check the Room Temperature
As mentioned, the main cause of frosting is related to your ambient room temperature. If the room temperature is sitting at less than 65°F, then there's a good chance this is the problem. If the temperature is less than 40°F, then this is definitely the problem. Another tell-tale sign of low room temperatures is an even layer of frost along the evaporator coil. If this frosting has occurred locally, then you can rule out room temperature as the problem.
If you think that ambient temperature is the issue, move your unit to a higher level in order to check this. Warmer air will always migrate towards the top of rooms, so by sitting your dehumidifier on a table or ledge, you can diagnose the problem accordingly. Another way to check this is by directing warm air towards the dehumidifier by using a hair dryer or electric heater.
Check the Distance From the Wall
The reason for this is that dehumidifiers that are situated close to the wall can suffer from a restricted air flow around the unit.
Check to make sure that your dehumidifier is at an ample distance from the wall such that air can move freely around the unit. Be careful not to sit your dehumidifier next to open windows or doors, as this will reduce the local air temperature around the unit and lead to the problems outlined above.
Check Your Condenser Coils
If your coils are clogged with dirt, their efficiency will be dramatically reduced. You can easily check this by unplugging the unit from the mains and removing the condenser coil to check inside. By vacuuming around the area, you can clear any blockages and remove this problem.
If your condenser coils are entirely iced up, then you should contact an appliance repair company to replace these parts. However, if they have only partially frosted over, then the problem is likely due to a lack of refrigerant fluid in the unit. Top the fluid up and check to see if this solves the problem. If the issue remains, then contact an appliance repair company such as Appliance Service Co Inc. or manufacturer as you will need these coils replaced.