I have a Holmes HM1850. Looks the same as the 1845. I have just cleaned it and started it running again. Heating season has begun. The humidifier, when the water level gets to about 50%, dumps it's water reserve onto the floor.Great for the humidity but kind of a mess. What causes this bizarre problem? Thank you, Bill Loughrey

The best solution is to buy distilled water or deionized water.

If the water has been sitting in the reservoir for days without use, it may develop a film on the ultrasonic element which inhibits the creation of the mist to come out the top of your humidifier. I would lift off the tank and empty the reservoir. Then VERY GENTLY with a piece of paper towel, wipe the ultrasonic element (looks like a disk the size of a quarter at the bottom of the reservoir) to clean off any film. Then replace the tank and let the reservoir fill up the tank and try it again.

Good luck
thebqe

Hard water will build up on the rubber plunger casket and the beveled edge were the plunger seats in the cap, if you clean both pieces it will seat it self again

You might need to clean around the heating element...
we have very hard water and calcium builds up on and around the heating element and all the surrounding parts. I take it apart and pour CPR around the element and scrub with a brush .. once you get it clean it should stay running.

Mine did this also so I unplugged it and took it apart and cleaned it. I used a sponge to clean all around the heating element with a mixture of white vinegar and water and also put some in the water resevoir and shook it for a few minutes and rinsed it out. It ran perfectly after I did this. It gets mineral deposit build up after a while so you might need to do this every week. There are directions on the back of the humidifer that explain this and what you should do. I hope this helped

This page has 18 pdf user manuals they are only 1-2 pages each open them in adobe reader till you find the one you need wish i could be more help
http://www.holmesproducts.com/Manuals.aspx

I am assuming a lime buildup from evaporated water. Use vinegar or drip coffee maker cleaner.

turn knob to reset....leave 15 minutes and then turn on

According to Holmes, one of the causes of the Reset light staying on is scale buildup on the heating element.

Remove Scale: Allow to cool before maintenance.
1. Repeat steps 1-5 in the Daily Maintenance section.
2. Clean the base by partially filling the base with one
8-oz cup of undiluted white vinegar. Let solution stand
20 minutes, cleaning all interior surfaces with a soft
brush. Dampen a cloth with undiluted white vinegar
and wipe out entire base to remove scale.
3. Rinse with clean warm water to remove scale and the
white vinegar solution before beginning to disinfect
the tank.
4. Wipe the heating element clean with a soft cloth after
it has had chance to cool.

If the scale has really built up it might take longer than 20 mins for the vinegar to get rid of it and you might need to refresh with new vinegar.

Your Manual can be found at this link:
http://www.holmesproducts.com/Manuals/Holmes/HM5250-UC_English.pdf

Good Luck.

Mine did the same, I cut one out of a piece of inner tube rubber. It has worked just fine for two seasons.