My air-o-swiss 7142 humidifier keeps giving me the empty indicator light to signify no water in the unit even though the base and the tank are full. If I try to reset it comes on for seconds and then shuts off again as if it's empty. Not sure where the problem is coming from...

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.

These hints are from the air o swiss webpage.
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.

If your issue is with the float and not the mister, then you have to make sure the float is tripping the micro switch that turns the machine on. Some units the filter will not allow the float to hit the switch if the filter is not installed correctly. If everything is in correctly and the float is tripping the switch, then the micro switch must be faulty.

does it have water in it

There is info on the FAQs from Air-o-Swiss:
http://www.airoswiss.net/service/faq.aspx#35


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.

Gererally according to the booklet in the box.
If you no longer have those instructions, simply clean out the
basin, make sure no mold, dust, hardwater or calcium is deposited.
Use a 10% bleach water solution to kill bacteria, and thats is basically it.
Just dont miss any spots, but humdifiers should be cleaned every few uses.

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.

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.

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.

sounds like the filter is not allowing air flow.

here is the manual if you need it http://www.plaston.com/uc/ats/products/ultrasonic/aos7133/index_html/manual on page 6 you can see item k - the water level sensor - i believe it is electronic not a float device (but either way the same is usually true)- usually these can fail when dirty - limescale mostly. a lot of the problems may be the result of not replacing the demineralisation cartridge often enough. descale by leaving overnight with around 40% vinegar solution full to the top, make sure the demineralisation cartridge is removed while u descale - check pages 9& 10. Hope this helps :)