This is the most common question that we are getting at the moment. Phone call after phone call telling us that their dehumidifier never seems to turn off and it is collecting lots and lots of water. Is this normal people ask us?
The answer is yes.
The Explanation – Why it’s normal.
The dehumidifiers have a built in humidistat that measures the temperature and relative humidity of the room and tells the dehumidifier whether to sleep or dehumidify. If you have a house that has never had a dehumidifier in it before then the dehumidifier will be running flat out for around two to four weeks while it dries out all of the air in the house and then the organic material in the house (wood, clothing, furniture, paper, books etc.) releases all of the moisture into the air that they have been holding on to, giving the dehumidifier more work to do.
As well as the above you are also putting moisture into the air each day (bathing, showering, cooking, breathing etc.) and this slows down the process of getting to a point whereby the humidity is low enough for the dehumidifier to turn off for a rest.
Then there is the weather, if it is raining a lot then the dehumidifier will run for longer. When it has caught up and brought things under control you will find that your dehumidifier turns off and then you will settle into a cycle of on/off/on/off as required.
After all you bought the dehumidifier to dry your house and that is exactly what it is doing for you. So don’t be too hard on your poor old dehumidifier!
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219 Responses
Hello I bought a 20L Low Energy Dehumidifier a few months ago. It’s been great until recently, it doesn’t seem to turn off despite being on 48 when set to 55? Also it was keeping our windows dry all winter but now I’m waking to condensation.
Mat,
Thank you for your purchase and your question. The reason why you are now getting condensation is because the windows were colder recently as temperatures dropped overnight, lower temperatures mean less moisture is required for condensation to form and if you want to prevent this you will need to run your dehumidifier to a lower relative humidity.
On the machine please press the droplet button once to check that the target has not changed, let me know what number appears when you press this. Cleaning the filter will help as well and if that is looking dirty, then blowing the sensor behind it through with a hair dryer will help as well.
Chris
Hi Chris I purchased a 12l dehumidifier some time ago and it’s worked like a dream. One issue I find at present is the display appears to show 46% all the time. Normally I’d believe it. However I’ve just washed the carpet and it still shows 46%. I’ve cleaned the filter no change. We don’t have a damp house but I’d expected that the moisture level might have gone up a bit the carpet feels damp to touch. Any suggestions?
The machine sits in the room and does its job quietly.
David,
Thank you for your message and your purchase. The moisture is in the carpet and not in the air, this is why the reading on the display is not as high as you might expect. If you want to speed up the drying process then select CO on the display.
A fan pointed at the carpet would force the moisture out of the carpet if you really want to speed up the drying process.
Chris
Hi. I have recently purchased the Arete 20L model. However it is switching on intermittently even when the humidity is set at 55 and the humidity in the room is showing 44 ? This doesn’t seem right.
Gary,
Thank you for your purchase, does the machine say 44 or a third party device elsewhere in the room? The machine should turn on and test the relative humidity in the room every 30 minutes, and then shut off again if the humidity is below your target.
If there is a fault, then you will get an error message on the screen.
Chris
Hi Chris. Thanks for replying so quickly. The dehumidifier is registering low 40’s and I have it set at 55. However, every now and then it will start up for about 10sec and then shut off again. Is this normal. Many thanks.
Yes, that is all fine.
I’ve been running my 20l platinum low energy dehumidifier for 3 days now, I have the desired humidity set to 55%rh – the unit reached that level about half an hour ago, but hasn’t turned off? Is this normal? Thanks
It will switch off when the relative humidity is 3% below your target.
Thanks for the reply Chris. Does that mean it needs to reach a value of 53 on screen (or more accurately 53.35, which is 3% of the required 55 value) or 52, so 3%rh lower than requested. If the latter, and given the unit only does increments of five, do I essentially need to set a humidity target of 60 to actually get the unit to switch off 57%rh. Thanks
Figured this out now. A setting of desired 55%rh will turn the dehumidifier off when it reaches a reading of 52%rh. Slightly counterintuitive but now understood!
It is to allow for sensor accuracy and stability in the environment. Otherwise you would turn off at 55%rh and then the humidity would edge back up straight away.
Hi. Mine doesn’t turn off even at 16% under the target humidity. I literally set it on 80% and it’s been on 64% for the last hour and won’t go to stand-by. Any advice?
80% is the wrong humidity to set the machine to and makes no sense. You want to achieve a relative humidity of around 5-0-55%rh. Press the stat button once to check what it is set to (and to change that setting to 50 or 55).
Hi Chris
My DD8L arrived on 24/11/22 and has been running constantly since (mostly on 1 fan and 2 drops/thumbs up, though I needed 2 fan and 3 drops to keep the windows dry during that cold snap before Xmas). My windows are always dry (hallelujah) but I’m starting to wonder if the humidity is too much for the unit. It’s been 7 weeks now, without the machine turning itself off. I’m not using central heating, so the temperature is low (13 degrees in one rooms today: 15 in another). Do you think it’s a matter of time, or should I have bought a more powerful machine?
Also, I saw that, in an earlier reply, you said that 2-fan mode is more efficient. So would using this mode save electricity (and therefore money) in the long term, despite the higher usage in the short term?
Thank you for your help.
Rachel,
Thank you for your purchase and your message.
If the dehumidifier is not reaching 50%rh then you have to ask the question ‘where is the water coming from?’ I would look at everything you do daily and think about whether you can reduce the amount of moisture released into the house. For example putting lids on saucepans when cooking, using extractor fans or opening windows in the kitchen and bathroom after use, doing an extra spin on the washing before bringing it out to dry. Those sorts of things.
The reason why you would have required to use the three drops settings during the cold snap would have been because the surface temperature of the windows was colder and therefore you needed a lower relative humidity to prevent condensation forming.
The dehumidifier will be giving you warmth as well as dry air, so you might like to balance up whether having some more warmth would be a nice thing and then that would balance the decision making towards using the second fan speed (more extraction and more wattage, therefore more warmth) or whether you want to try and reduce the level of moisture being released into the house and keep your running costs down.
Chris
Thanks for your reply.
The thing is, I already do all that: lids on pans, extractor fan when cooking, bathroom windows open after shower, laundry dried outside or in a small room with the dehumidifier (before I had the dehumidifier, with the window open) I’ve always been careful about reducing moisture as much as I can. I can’t think what more I could do to reduce moisture coming in.
I’ve got stripped floorboards in my lounge. Could the moisture be coming in through gaps between the floorboards?
I don’t understand your response to my question about whether to use the higher fan speed. What I’m wondering is: if I use the higher speed, will the extra power used be more than cancelled out by the dehumidifier drying the house faster, and therefore powering down. I’m wondering which is more energy efficient: drying slower for longer vs drying faster for less time. Can you advise?
Thanks for your ongoing help.
Rachel
Rachel,
At the end of the day the moisture has to come from somewhere and if it is not coming from daily activities then it will be moisture that is stored in the house and is being released by the organic material as the house dries out. By organic material we mean anything that is wood, paper, leather, fabric etc. It will get there but for now it will still be drying out the organic material within the conservatory, for every litre that it removes, the organic material will release the same amount of moisture. This continues until the organic material is dry.
With regards to the running, as long as you as sure that this is not moisture coming in from outside, it will be worth running the machine on the higher fan speed because the increased airflow will drag moisture in from a wider area.
Chris
Thank you for your further thoughts.
I hope it finishes drying out the house soon: my electricity bill is getting scary!
I’m still not clear which will use more electricity: the higher fan setting/drying the house faster; or the regular fan setting/drying the house over a longer period of time. Do you know the answer?
Rachel,
It is an important point with this machine that the energy used is also converted into heat, you are getting dehumidification and heat from this process.
Which will use most electricity is hard to answer because we don’t know where the moisture is coming from, for example, I mentioned about the window being open and how that will effect things. We don’t know how much air is being replaced and what the temperature differential is.
I would use whichever setting you are more comfortable with. Turning the heating up a couple of degrees would also drive the relative humidity in the space now by about 6%rh, the combined effect might be enough for you (depending on how damp the structure of the house actually is).
Chris
Hi ive turned my Meaco off at the plug mid cycle and now it won’t go back on, just keeps flashing
I don’t know which model you have. But turn it off at the mains for 30 minutes and then restart it. If you still have a problem then please call us on 01483 234900.
Thank you for all your replies.
As of today, my dehumidifier has FINALLY gone into sleep mode! 14 weeks, that took!
Don’t give up, folks!
Rachel, thanks for the update!
Question: how old is your house? Mine is 100 years and I’m thinking that my dehumidifier might be processing decades of water infiltration.
David,
All houses are different, it will be a combination of factors that determines how your dehumidifier is running. The big one is how much water you are putting into the air each day, whether you have working extractor fans and then if you have any structural issues in the house that is causing water ingress from outside to in.
Chris
Hi there when I’m running my dd8l junior dehumidifier on 2 drops setting or 3 drops setting it’s doing the fan only mode for 5 minutes when target is achieved but it doesn’t go to sleep it carrys on dehumidifying.on the 1 drop setting it does fan only mode then goes to sleep is this normal thanks.
Lee,
This is normal because those three settings are 40/50/60%rh and all this tells you is that the humidity is somewhere between 50 and 60%.
Chris
Hi Chris
I just purchased the DDL8 Junior machine due to condensation in my living room after putting the heat on in this freezing weather.
It reduced the humidity from 70% to 40% in just two hours which was very impressive! at this point I turned down the fan speed to one and humidity to normal (thumbs up setting) to save on the energy bill. It has however been operating non stop since! My RH reading is still around 44% but the fan keeps running. It’s been like this for approximately 5 hours now and I’m quite concerned about the effect this will have on my electricity bill… am I doing something wrong? I thought the machine is meant to turn itself off once the relative humidity is under 50%
Martha,
It will turn off when it sees that the relative humidity is 3%rh below the target and stable. So leave it to do it’s thing and it will turn on and off as required. Anything else you are using to measure humidity just use as a guide, rather than being 100% accurate.
Chris
Hello,
I bought MeacoABC 10l, two months ago.In the beginning was 70% humidity, and dehumidifier was working non stop days and nights and collected lots of water,but now it doesn’t automatically shut off once it reaches the target.
Target humid level is 55, couple of days is showed 48% and it still not turning off.
It is not collecting water and some time shut off when reach 47-48%.,but defrosting light is on constant.
Last night it was off all night,in the morning I turned on with target 55%,and it appear defrost light and start working even showing that the humidity is 48%.i give some time to work and changed target till 60% to see if it will stop.it stops after couple minutes,but when reach 50% turned on again.
Filter cleaned couple times .
Is it faulty?
Thanks in advance
Tetyana
Defrost light is fine, don’t worry about that and never turn it off when it is defrosting. Make sure that the filter is clean and you can clean the sensor behind the filter if you like with a hair dryer. The machine sounds ok, just let it do it’s thing.
Day and evening hours are very different.
Purchased two MeacoDry Arete One 12L Dehumidifier / Air Purifier. Love the machines. Why two machines, I like my downstairs door closed. So I have one machine serving upstairs and one downstairs. It seems to work.
Question
Have the machines running. The temperature upstairs is 16C during the day and 19C in the evening. Downstairs 17C daytime 20C evening.
The first switch on and the humidity was 67%. been running the machines 24/7 for 3 weeks now. Humidity is approximately between 60 – 58% by day, however, when I put the heating on in the evening the humidity value drops to 52% at which point the machines switch off. They can have a deserved rest! When the house cools the machines are constantly on
Why do the machines struggle during the day, is it because of the temperature? Need to add, we had over 8 inches of rain, so it’s been very damp here.
Thank You
Shaun
Shaun,
Thank you for your purchase and your message.
It takes a while to dry a house out, there is the moisture in the air, the moisture you add everyday and the moisture that is now being released by the furniture, books, walls and paper products every day. Expect things to settle down after about 6 weeks.
Chris
Using a DD8L junior, what is the recommended setting for an initial dry out for a 2 bed flat to minimise electricity costs? Run it on constant on low, medium or high fan on the 2 drop setting?
Steffen,
On a DD8L Junior you have the choice over these things. Running it on fan speed two uses circa 650 watts, fan speed one halves this to 330 watts. When you half the wattage you also half the extraction rate. To dry the flat out set the humidistat to the thumbs option on the control panel (50%rh) and the machine will turn off when this target has been reached and will turn back on whenever the humidity goes back up.
I would run it on full power until the humidity is under control and then reduce it to half power from then on.
Chris
Thanks Chris,
I’ve done as suggested running it on the 2 fan setting and now the machine is going into sleep mode ~3 times a day. However, switching to half power is problematic- to cycle from 2 fan to single fan requires going into laundry mode which take it out of sleep, after which it just runs continually. I always run at half power during the night to keep the noise down and it’s always running if I wake up during the night as well as when the alarm goes off in the morning.
Is this normal behaviour?
This suggests that it is getting close to stability, but not quite. I would run it during the day on the two fan speeds and switch to the one fan speed at night. In a week or two I would try single fan speed all day long, it will go to sleep if it hits the target.