Dehumidifier Freezing Up

..."If your dehumidifier coils are freezing up and the room temperature is above 65 degrees Fahrenheit, there may be an issue with the humidity control. ... If the humidistat is not reading the humidity correctly, the compressor will stay on which can cause the coils to freeze up."...

https://www.partselect.com/Repair/Dehumidifier/Coils-Icing-Over/

BUT...

If the humidity is still over 60% and want it lower, and yes it is warm in the room it is in, probably 75 deg F or so.

Now what?

Joe

Then possibly the filter is clogged....but more probably the unit is leaking refrigerant...so time to get a new one...

No filter, so that cant be it, he he he,

and if it was leaking refrigerant would it also not get cold. I mean it is SUPER cold sooo cold that the it has to be far below freezing because the water simply does not just condense and drip down, but it freezes in place.

ahhh I see,

so If I let it melt down and start it up, I should see it freezing at one location first. Right now it seems to appear to freeze evenly across the whole coil.

It's possible the fan is not working properly....not moving enough air through the evaporator coil....It's also possible that there is a defrost cycle that is not working....

http://www.best-dehumidifier-choice.com/what-is-auto-defrost-and-why-is-my-dehumidifier-defrosting-so-frequently.html

What is the make and model of the dehumidifier?

too old and beat up to know got it at a garage sale.

I suppose I could make a dual adjustable timer, see how long it takes to ice up enough and how long to melt down, and make a timer to turnn iton and off for me he he he.

Well the defrost timer usually just turns the compressor off and leaves the fan running to defrost the coil, so you could time the compressor to say 20 min on and 5 min off and repeat...without the fan running it would take a long time to melt the ice just sitting...Most would be controlled with a thermostat that when it hit a certain temperature say 20° F the timer would start, then after a time the compressor would shut off, the fan continue to run, and when it hit a certain temperature, say 40°F, then the compressor would come back on...Refrigerators are usually on a set 24 hour clock that defrosts every 24 hrs, but they have heating coils that are intertwined in the evaporator coil, so they defrost rather quickly and the defrost cycle terminates via thermostat...Commercial freezers have defrost cycles that can be set for every 2 hours or so...these are like the timers you see for sprinkler systems....so that would be your best bet to get a sprinkler timer....

Your machine is low on refrigerant or not moving enough air across the coil. Is condenser and evap clean?

If air flow is sufficient you have a leak.

Look for a sign of oil leak stain. It will be close to the area of the leak.

Mix dish soap and a little water then daub the soap around the area. The smaller the bubbles the better.

Watch for signs of bubbles forming with Compressor off.

You should find the leak at the bubbles. I am assuming there is still some refrigerant in system.

Add access port on low side. Silphos 15% is best. Take out Schrader valve and then heat up and seal the leak and access port. Evacuate system then charge to above 35 degrees.

If he was a refrigeration mechanic and had all the tools and knowledge necessary to do this repair, he wouldn't be here asking these questions...

Had the same problem. Turned it off till the coils were completely defrosted. Turned the knob to where it just started running and left it there for the overnight. Gradually adjusted the setting making it a little drier each time. It would run long enough each cycle to lower the humidity a little more without running long enough for ice to build up. Took about a week to get the humidity level where I wanted it. It has been running for years now with no further ice issues.

Improve the air flow past the coil:

• Clean the coil
• Increase the target humidity setting
• Increase the refrigerant minimum temperature setting
• Close the door of the room in which it is located.
• Switch the thing off during periods of low demand
• Etc.

And if skills or courage to do any of these are lacking:

• Call a Service Technician on 0800-FIXMYFRIDGE and arrange a site visit from that individual to rectify.

No filter,you say? Then the evaporator coils are probably dirty.They do not have to be totally clogged,a dirty coil will be a lot less efficient than a clean one.Buy some no-rinse coil cleaner and used as per the directions.

You should consider adding a filter if possible and space allows.

Try to find the model number and look it up online,it may have some with a filter,but missing when you got it.Look in all of the hidden places,like behind covers,inside of covers,etc. and under the bottom of the unit.It should be there somewhere.

I am sorry. I have the same issue but didn't find the answer. Are there any specialists? What's the reason? Is this fixable or should I replace it?

I am not a specialist,but I might be able to make several helpful suggestions.

All of the suggestions above are pertinent.

Are the fins on the cooling coils clean and straight?

If they are bent,or folded flat,this will reduce airflow through the coils,causing ice to form.

If they are bent,buy a condenser fin comb,also called a coil-fin-straightener to straighten the coils.

https://www.amazon.com/Condenser-Straightener-Conditioner

Clean the coil with a no-rinse coil cleaner:

https://www.amazon.com/Nu-Calgon-4171-75-Rinse-Evaporator-Cleaner

If it has a filter,replace it or clean it.

Check that the fan is running at full speed and no accumulation of dust on blades.

Make sure the humidistat is working by turning it to it's lowest setting.

It should stop.If not,the thermostat is defective and should be replaced.

And last resort,the unit may be low on Freon,which indicates a leak somewhere.

Low Freon will cause a reduction in pressure across the evaporator coil,and reduced pressure will make the Freon "flash"at a lower temperature,resulting in a below normal temperature at the coils.

It is not usually cost effective to recharge such a small unit,so replacement is the best option.

Good luck.

Yes, thanks! I was reading your reply and thought that that's too much for one dehumidifier. Condenser costs $10 when a new dehumidifier from the top of the list. So when you told about the replacement in the end, I was already thinking about that, thanks!

Does the unit have an evaporator pressure regulator to keep the refrigerant temperature above 32dF? If so, and if properly adjusted, the unit shouldn't freeze up at all.

Alternatively, is there a defrost timer; i.e., is the unit designed to allow frosting?