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!
Products featured: Dehumidifiers
240 responses
Hi Chris, we bought a Meaco DD8L Junior Dessicant in August to run in our single skinned utility room to maintain a sensible humidity level., it’s been great, ran for a while initially then stabilised, cutting in/out on the settings of 1fan/two drops maintaining a 50ish% humidity on a separate digitl reader in there. Today however, whilst it would normally cut out when it requires emptying and the light for the container would come on, the light flashed but the machine fan has continued to run. We’ve left it a good hour or two and still nothing, even after emptying the water out. A little concerned something is wrong as the machines been on and running in there fine for months, always turned on and cutting in / out as required, usually requiring emptying maybe every day and a half. As it wouldn’t stop we have turned it off completely at the mains and restarted but it’s still just running the fan. Can I ask for your thoughts, it’s not something it’s done before and feels like a fault. Cheers, Jeremy
Jeremy,
One thing to check. Turn the machine on and let it run, if you then remove the tank does the machine turn off (it will do it’s three minute cool down first)? If not then please call us on 01483 234900 and we will sort it out for you.
Chris
Hi Chris, just to say thanks very much for the time to reply, appreciated. We left it overnight, vacuumed the vents, filter etc and blew a cool hairdryer through it too, just in case any dust lodged anywhere and restarted. So far so good, ran most the day then reverted to stopping periodically as expected/in line with moisture levels. This time when full after its initial run it beeped and the fan stopped. Normal service appears to be resumed but will call if not, thanks again for the support, massively appreciated.
Not a problem, please feel free to contact us again if you need to.
Generally happy with my 12l. Amazing tge amount of water! It turns off randomly round about the 60 I choose and then only for a few secs. Am I setting the RH correctly please?
Jean,
Thank you for your purchase. You can check the relative humidity you have set the machine to by pressing the up or down arrow once, the number will then appear on the screen for a few seconds. From what you describe it is close to hitting it’s target but is not quiet there yet. Once it maintains the relative humidity just below 60%rh it will start to turn off and stay off for 30 minutes.
Chris
Hi Chris
I have a Meaco Low Energy 12l. When it is first turned on in the morning in my daughters bedroom, which had a cold damp patch on the chimney it says RH is 98%. Is that the correct room reading or an internal reading?
Paul,
Thank you for your purchase and your email. the reading will be the dehumidifier’s internal humidity because the fan is not turned on. Once the fan has been running for a few minutes then that is the room humidity.
Chris
Hi,
I have the Meaco 10L dehumidifier which I bought last year. When set on the normal setting for 60%, it will often run the fan without the compressor for hours on end not collecting water. Also what does it mean when the red light stays on but the green power light goes off? Because that also happens sometimes.
Peter,
Thank you for your purchase and your email. The green light goes out when you have reached the target relative humidity. If the machine is running for long periods of time but you are getting no water then that tells you that you are right on the target relative humidity.
Hope this helps.
Chris
My husband bought a new Noma dehumidifier 2 weeks ago and started it running the same day. Our old one had quit about 3 or 4 days previously. But this machine has run constantly since starting it up. How come it never quits?
Maxine,
This will be because the relative humidity is still above the set point that you have set on the machine.
Chris
Can you still buy a dehumidifier that works for 4 hours then shuts off for 4 hours then back on?
Peggy,
Not really and you would have to ask why would you want to? The article I have linked to below basically explains why. If you send the dehumidifier to sleep then you run the risk of missing episodes when the relative humidity is high and this moisture could damage organic material in your house.
https://www.meaco.com/blog/when-should-you-use-a-timer-on-a-dehumidifier/
regards
Chris
I am VERY happy with my Friedrich dehumidifier. But I do not understand why it runs when we have not had any rain for
3 or 4 days. With this unit in my basement laundry room, it has greatly reduced the “spalling” from the basement
foundation cinder blocks. Is there anything else I need to do because of the spalling?
I do not want to call a basement waterproofing company because I have read too many bad things about them in the publication: Washington Consumer’s Checkbook. I do not want my basement torn up to install a sump pump and I do not
want a company that uses outside contractors.
Any suggestions for me?
Morton, Thank you for reaching out. Sitting in my office in Guildford, England I am probably not the best person to comment on Washington contractors. But although rain can raise the relative humidity it is not the only source of moisture and dehumidifiers are often triggered by the slow release of moisture from organic material like brick and timber. Is the basement is partially underground in a wet area this can be a continuous battle.
Mr.Chris I have an old simplicity 38 dehumidifier .I put the Rh at 60 or 70 .when started the screen LCD indicated 90 Rh. After about a week tuning day and night reached 58 Rh but not stopping.it drains in a floor drain. I want to use a Dayton plug in 120v controller humidistat set at 65 so to stop there.pleas say if I m OK. Thank you for helping the village.
Mike,
Thank you for reaching out, this is not one of our dehumidifiers but I can give you general advice. Ignore any reading on the display when the fan is not running, this will not be representative of the rooms relative humidity and will be a reading of the internal dehumidifier conditions. If you are setting it to 60%rh and it is running to 58%rh then that sounds reasonable because you would want a slight over run to take into account sensor accuracy. using a plug in humidistat switch is never a good idea because you will be reducing the lifespan of the components because they are never designed for a forced power cut like that and you are not allowing the dehumidifiers systems to close themselves down properly.
Hope this helps.
regards
Chris
Hello Chris, As a florida resident i did not need the heat the unit was putting out so i piped it out of the house along with the drip line. Will this in any way adversely affect function ?
Robert,
Not sure what you mean by piped it out? the heat comes out with the dry air so that has to go into the room. The water collected can be drained away continuously but there is no heat there.
Chris
Hi Chris,
I think most people (including me at first) expect the dehumidifier to turn off quite quickly when first used – I did not appreciate that it has to dry the room out first!
Would you recommend the use of a hygrometer to keep a check on the moistire levels? Do any of your models have this feature built in.
Thanks, Scott
Scott,
All of the dehumidifiers have a built in humidistat which measures the level of relative humidity and turns the dehumidifier off and on. Buying a seperate humidistat just confuses matters in our experience. The following blog post will explain why – http://www.meaco.com/blog/?p=438
A dehumidifier will run and run until the house is dry, first the air gets dried and then the organic material in the home releases the moisture that it hs been holding onto which pushes the humidity back up. Of course whoever is living in the house also contributes to the humidity as well. from experience dehumidifiers will run hard for about a month and then settle down.
regards
Chris
I would like to know if there is a dehumidifier on the market that the fan shuts off after it reaches the desired humidity? It is going in a bedroom and the one I have now the fan never shuts off.
Pat,
Our machines do that, for a bedroom go for teh MeacoDry ABC 10L because it is by far and away the quietest solution.
Chris
I have just bought an ABC 10L and it does not turn off when the pre set humidity is reached (according to the display). Is it faulty?
Mike
Thank you for the purchase and the message. The machine should run until it is 3% below the target.
Chris
Hi I have a similar problem I have the same machine and it’s been working fine for about 2 years. However over the last few days even though I’ve set the thermostat to 60 it keeps on running and doesn’t turn off. The humidity it’s registering is 30. Won’t turn off unless I manually turn it off. Is there a fault? I’ve been diligently cleaning the filters every few weeks.
Jay,
It is a good idea in these situations on a older machine to blow through the return air sensor behind the filter to remove any dust.
Chris
The new dehumidifier seems to increase from 50/55 to 70+ now and then without obvious cause (eg cooking, showering). Sometimes it is high and decreases quickly. Is this normal?
Peter,
If this happens when the fan is turned off then it is fine, the high reading is when it is reading it’s own internal relative humidity.
Chris
Just bought Merco 20ltr dehumidifier but it is not switching on? Help….
This means that you are holding your finger down on the On/Off button for too long. It just needs a quick press.
My dehumidifier will not go less than 62 at the moment for some reason even if set at the lowest 30. I have the low energy 12L should I be getting it fixed it had been working fine.
Sarah,
As long as it is collecting water then it is fine. Make sure that the filter is clean and that the air inlet is not blocked. Keep the machine on 24/7 and progress will be made.
Chris
Hi, Just purchased the ABC12L and have a couple of questions. One of the reasons I purchased this particular unit was the low running cost but found that when the defrost light starts flashing the fan speed also increases to the higher speed, is this normal? Also, I find that it will at times increase the fan to a higher speed without the frost light flashing even though it was initially set to the lower setting. Because of this I’m reluctant to leave it running overnight, fearing that it will run all night long at the higher speed, doubling the running cost.
Dave,
Thank you for your purchase, the change in fan speed is normal and vital. But the increase in fan speed only changes the electricity consumption by about 10 watts, so you will not even notice it on your bill.
Chris