20 Most Recent Air-O-Swiss U7142 Humidifier Questions & Answers

I have got the same problem with my u7142 unit. This most probably means that the hygrostat inside is either broken or it has been heavily covered with the "white dust" in case the demineralization cartridge has not been changed for a long while.
To resolve it you have two options: either clean the humidity sensor or replace it. The sensor is at the bottom of the front panel, so you need to disassemble the front panel only, no need to open the whole unit (note that there are 2 screws at the bottom holding the front panel also). You need to get the sensor out from the printed circuit to open the cover and clean the surface of the sensor with something (blowing air does not help; you need physically touch the surface with something). If it does not help then you can go for the second option to replace the sensor, the type used in the unit is SYH-1. It is not a pricy element so you may go straight to the replacement if you find a shop nearby to buy it. I have simply replaced the sensor and now the unit is showing the proper humidity value and adjusting the steam automatically again.

Air-O-Swiss... | Answered on Mar 12, 2020

It is intersting that several folks seem to be having this problem. In early December 2009 I noticed that the replacement AOS demineralization granules were wet when I opened the sealed metal envelope. I opened a couple of others and they were the same way. After a couple of weeks after replacement, the unit started puffing steam before it stopped altogether. My husband opened the cartridge and said all the crystals were clumped to one side. I emptied out the cartridge and ran it for a few days (about 4) without any crystals until it stopped generating mist altogether. Air still flows and the heater works. But it appears that the ultrasonic disc in the bottom of the unit quit. Not sure if this was all coincidental... Especially when seeing several other people with the same problems over the last couple of months.

Tonight the AOS customer service/tech support said I shouldn't run the unit without the crystals but they appeared to be concerned about the white dust.

Anyway, the AOS U7142 has a three year warranty. If you have a receipt call customer service at 1-800-336-0326 immediately. If it is after three years they said they would charge $60 to fix it.

Air-O-Swiss... | Answered on Mar 26, 2017

The water sensor is a float in the mister area of the base. The float is off in one corner with a little plastic barrier around it and translucent cap over it. Make sure the float can more freely. If the float can move up and down but the light stays on, the reed switch (a switch controlled by a magnet built into the float) inside the unit might have been knocked loose, damaged or disconnected. The switch is actually inside the post that the float slides on, but it can only be accessed from the underside - inside the unit.

Air-O-Swiss... | Answered on Jan 11, 2015

Its probably the cleaning light that comes on periodically to remind you to clean the unit. Shut off the unit AND when you do so hold down the power button for several seconds until the flashing red light shuts off. The cleaning light should stay off until the next cleaning is due.

Per the Air-O-Swiss FAQ:

Q: Cleaning light is flashing (AOS U650, AOS 7135, AOS 7142, AOS 7144, AOS 7147)
A: Switch the unit OFF and unplug it. Empty the water in the base. Rinse the base with hot/clean water. Do not submerge the base! Visually inspect the base for dirt or mineral build up. If soft water is used decalcifying the unit every 4 weeks with EZ Cal is suggested. If hard water is used the unit should be decalcified every 2 weeks. Do not forget to reset the clean light after resetting the unit.

Q: Reset cleaning light (AOS U650, AOS 7135, AOS 7142, AOS 7144, AOS 7147)
A: The cleaning light does not automatically reset. Hold down the power button (button A in instruction manual) until the light stops flashing. The light automatically comes on approximately 14 days after plugging in the unit.

Air-O-Swiss... | Answered on May 17, 2014

does it have water in it

Air-O-Swiss... | Answered on Mar 08, 2011

There is info on the FAQs from Air-o-Swiss:

Q: No mist / unit is not working / empty indicator keeps flashing
A: Fill up the water tank. Check if water is flowing through the demineralization cartridge (attached to the water tank cap). If the water tank is full but there is only little water in the base it indicates that the water is now flowing through the demineralization cartridge.

  • Wait for 15 minutes to allow the mist to come out of the unit.
  • If the unit is not working and the empty light is not flashing you might have set the desired humidity too low and the current humidity level in the room is higher. That is why the unit switches off automatically.
  • If the empty indicator continues flashing and the tank is full, water is not flowing through the cartridge. Exchange the cartridge or the granules in the cartridge after 2-3 months, in areas with hard water exchange the cartridge after 1 -2 months. However, the demineralization cartridge and or the granules must be exchanged at the latest after 6 months or the unit does not reach its full performance.
If the granules are new, see the following instructions:

  • Make sure the cartridge and/or granules were soaked for 24 hours, water takes longer to filter through dry granules in cartridge and into the base. Next, remove 2 tablespoons of granules from the cartridge, and throw them away. Too many granules in the cartridge it does not allow water to flow from the tank to the base.

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Q: Unit is running intermittently.
A: How long has it been since the contents of the cartridge were replaced? If 2-3 months have passed, it is time to replace the contents of the cartridge. However the demineralization cartridge and or the granules must be exchanged at the latest after 6 months or the unit ceases operating at its full performance. If the contents of the cartridge were just replaced there are probably too many granules in the cartridge. Remove 2 tablespoons of granules from the cartridge.

Air-O-Swiss... | Answered on Mar 08, 2011

  • Sorry to read about your problem, I hope this helps you out.
  • you could say you have dirty water. Unplug the humidifier from the wall.
  • 2 Remove the existing water from the humidifier. Water contains several types of minerals, including iron and sodium, which cause the white powder when released into the air.
  • 3 Clean the humidifier according to the manufacturer's instructions. This may involve disassembling the unit and replacing the humidifier's filter.
  • 4 Pour demineralized or distilled water into the humidifier's tank. These liquids have a lower mineral content than tap water.
  • 5 Consider switching to a humidifier that comes equipped with a demineralizing filter, which removes the minerals found in tap water before they are dispersed into the air.

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    Air-O-Swiss... | Answered on Dec 31, 2010

    There are a few hose connections inside the unit related to the heater element. Water flows from the reservoir down into the unit, takes a turn into a tube with the heater element wrapped around it, then turns back up into the mister area. Any of the four connections (base to first elbow, elbow to heater tube, heater tube to second elbow or second elbow to base) could be leaking.
    The white ring around the mister disk cracked on my unit, letting water leak out the bottom as you describe... Take a close look at that.
    It's also possible the base itself is cracked somewhere... Look closely at the mister and reservoir areas of the base for cracks.

    Air-O-Swiss... | Answered on Jul 28, 2010

    Any bathtub cleaner will work so much as you do a good job cleaning then rinsing. Be careful not to get the humidifier wet anywhere other than the basin that the water goes through.

    Air-O-Swiss... | Answered on Mar 06, 2009

    You can download the manual here: http://www.homeairtreatment.com/airoswiss-aos7142.php

    Air-O-Swiss... | Answered on Jan 24, 2009

    You have to press the power button and hold it for several seconds, and it will reset.

    Air-O-Swiss... | Answered on Nov 08, 2008

    I just cleaned mine for the first time, and the instructions are very unclear in the pamphlet on how to do it.
    What you need:
    One package of EZ Cal cleaner/descaler for humidifiers ( I got mine at bed bath and beyond)
    32 oz of hot water
    How to clean your unit:
    Mix the hot water with the EZ Cal cleaner packet in a separate container.
    Remove the tank from the base.
    Remove the cleaning brush and the silver stick that is in the base of the unit.
    Pour the solution in the base of the unit.
    Let the solution sit in the base of the unit for 1/2 hour.
    Then take the cleaning brush, and go over the surfaces in the base.
    Pour out the solution, and rinse with hot water.
    Put the brush and silver stick back into the base.
    Put tank back onto the base.
    Reset the unit by pushing and holding the power button for a few seconds.
    This will stop the cleaning indicator from blinking.
    Let the water fill up the filter for a couple minutes, turn on, and your ready to go again.
    I hope this was helpful.

    Air-O-Swiss... | Answered on Nov 08, 2008

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