It’s one of those simple, cheap little things that sits on the floor and comes in two pieces. There’s a roundish shaped reservoir and a piece that fits on top. The steam comes out of the round piece on top through a hole. I think it was $20.00 originally, and it’s a Walgreens store brand. I lost the instructions that came with it that explained how to clean it!! Vinegar was involved. Does anyone know??
You can fill the reservoir with hot water, add a cup of vinegar and let it sit for an hour or two. Then rinse and scrub with a plastic scrubby pad.
The top piece usually contains a couple of carbon electrodes. Over time these get crud on them, or even degrade into a fine black powder. If the electrodes look reasonably intact, you can soak them in straight vinegar to remove mineral deposits. Just immerse the top to the normal level;you can tell how far by the built up salts on the outside of the electrode case) in a pot of vinegar. Don’t soak the whole thing. Do NOT plug the unit in while the electrodes are in vinegar, that’ll cause bubbling and popping and overheating and generally awful things to happen. I tried it once, and the electrodes fell apart. After a few hours soaking, rinse the electrode case several times with clean water, and you’re ready to go.
In some areas, the salt content of tap water is high enough that electrodes will only last a year anyway. If that’s the case where you are, your only option is to get a new unit. I’ve never found replacement electrodes.