How to take apart a Honeywell HCM-890 / HCM-890B humidifier

Over time, humidifiers tend to collect dust and dirt inside them.  The fans, covers, and water reservoirs can get dirty if they are never cleaned, which reduces the quality of the air and water vapor being put out by the humidifer.  Cleaning out the humidifier is part of the preventive maintenance that it needs periodically, just like changing the filter.

Humidifers can be tricky to take apart.  A lot of times the screws or tabs are hidden.  To take apart a Honeywell HCM-890 (white) or HCM-890B (black) humidifier, follow the steps below.

First, unplug the humidifier from the outlet so it doesn't accidentally turn on.  Then remove the main humidifer unit (the big part with the control knob) by lifting it straight up.  (The cord will come with it.)  Turn the unit upside down so you are looking at the inside.

Remove the control knob by pulling it straight out.  There is one screw holding the motor assembly inside the cover; remove this screw with a Phillips screwdriver.  It will need to be a screwdriver with a long, thin shaft in order to reach the screw.  A #1 Phillips screwdriver will work best, but a #2 driver should also do the trick.  If you have a screwdriver with a magnetic tip, you won't have to worry about dropping and losing the screw.

On the other side of the main motor unit, opposite the screw, there is a tab holding the motor unit to the cover.  Pop this tab out to free the motor unit.  With the tab popped free, you can remove the motor unit from the cover (just be careful of the power cord).

Now you can clean the guts of the humidifier.  The cover can be wiped down with a damp cloth, and canned air works great for cleaning off the switch, wires, and circuit board.  The canned air may clean some of the dust off of the fan and vent, but to really get them clean, you'll probably need a damp lint-free cloth or rag.

Once you've cleaned the unit, let it dry before reassembling.  Push the motor unit back into the cover housing, making sure the tab pops into place, then reattach the screw.  Push the control knob back onto its shaft (it should only go on one way) then you can turn the unit right-side up and place it back on the humidifier base.  The next time you turn it on, you'll get a purer, cleaner vapor.