Coils will not heat up - Whirlpool AD25BBK Dehumidifier

Well the simple answer is, you don't. The air is being dehumidified by passing it over cold coils (same process is used to cool your home). The moisture in the air condenses on the coils and drips into a drip pan. The cool air is then discharge back into the room.

Try pointing the dehumidifier so that the discharge is directed away from people. Towards a heat source such as a window may offset some of the ill effects.

The normal operating temperature is above 65 F. Much below unless specially designed for low temperature they will freeze up.
They have a frost detector and will defrost but it is very inefficient and not practical. My experience they eventually form a block of ice on the coils. They heat the room in the process so in a moderate area they can raise the temperature and provide needed circulation.

In the past where the temperature is cool I have faced the output into a corner, raised it off the floor and once the unit got started the heat created from the unit kept the air warm enough to avoid freezing up the coils.

Always check for recalls. Some models have had problems and have been recalled. See the link below.



Gree Reannounces Dehumidifier Recall Due to Serious Fire and Burn Hazards...

Hope this has helped?

frost on the coils of a machine is an indicator of low air flow across the coils ,and also a decrease in the gas charge inside the machine , the first usually causes the second , due to increase in heat build up , its gotta expand and vent to someplace when it gets hot

With heat pumps that's the way they work. In heat mode they are using the evaporator as the condenser and it blows heat out the front and cold out the back. In cooling mode, a reversing valve switches the gas flow reversing the operation of the coils and it blows cold out the front and heat out the back.

Yes. Wet clothing would act to put Humidity in the air. think of the air as a sponge the more you heat the air the more the air will take moisture out of its surrondings. The more you cool the air the less moisture it can hold.
a Dehumidifier is a reverse refrigrator.. Air is forced over cool coils and the moisture forms and freezes on the coils (ice). The unit turns off and the coil and ice takes heat up from the surrounding area (makes room colder;Clothing takes longer to dry; The temperature in that room should be were people reside 70-80 degrees). the ice melts and water drips into a holding container which you dump periodically. Solution: 1. remove wet clothing or 2. raise temperature in room. 3. put a space heater in that room instead of Dehumidifier

comes on automatic - two coils, one cools/condenses on outside of it, other heats/defosts, both same system and work at same time

Most dehumidifiers have a defrost mode in which the compressor is turned off to give time for the frozen water to melt. The freezing problem ocurrs when the unit is used in very cold weather. Check your manual to see if this unit comes with automatic defrost mode. If it does, it would appear that it is not operating correctly and you can request warranty service. If no defrost mode is available, then your only option is to heat up the room in order to use the dehumidifer within its limit of operation. Some units can operate as low as 36 F, but most units cannot go that low. Find out what your unit's specs are from the manufacturers web site.

Three possibilities for coils icing up.

1. Low ambient temperature in the area where dehumidifier is located. If so, shut down and de-ice it. Then move the unit to a different - (warmer) - location and start it up.

2. Heating element - (which cycles periodically to liquify frost on the coils and allow water to drain) - is malfunctioning.

3. Low refrigerant level in the unit.

I believe a dehumidifier is supposed to operate in temps above 60 degrees. Even though your house is warmer than that, the air entering the dehimidifier may be getting into that range due to it being on a basement level etc. This is perfectly normal and is not a malfunction with your humidifier.

Your options are to either place the dehumidifier closer to a heat source in order to keep the air which is entering warmer. (I've even heard of someone placing a light bulb in front the unit during winter to warm the air slightly as it enters). Because the dehumidifier's coils get cold in order for it to collect moisture from the air, if they are freezing, giving the unit a rest for a few hours every few hours may allow the coils to thaw in between and prevent them from reaching freezing temperatures while running. You could use a timer to accomplish this, but you'll want to insure that it's a commercial grade timer in order to handle the electrical draw that the dehumidifier requires.

You prob do have a restriction in the sealed system. This causes the coils to not heat enough to stay defrosted. 68 degrees i believe is the minimum so if its 70 its def got a issues with the coils not staying hot enough to stay defrosted. This will most likely require replacement. Especially if you have cleaned coils and still freezes. Try it in different room. If persists most likely a sealed restriction. Replace.