What to Look For when buying room humidifier?

Without brand and model, my advice is definitely a shot in the dark. Only your manual or your manufacturer's site can inform you of what the flashing means.

Here are some tips that might help you increase the humidity in your room:

Check the humidifier's water level: Make sure that the humidifier has enough water to function properly. If the water level is low, the humidifier may not be able to produce enough moisture to increase the humidity in the room.

Clean the humidifier: Over time, mineral deposits and bacteria can build up in the humidifier, which can affect its performance. Clean the humidifier regularly according to the manufacturer's instructions.

Place the humidifier in the right location: Place the humidifier in a central location in the room, away from walls and other obstructions. This will help the humidifier distribute moisture evenly throughout the room.

Use a humidistat: A humidistat is a device that measures the humidity in the room and automatically adjusts the humidifier's output to maintain a desired humidity level. If your humidifier does not have a built-in humidistat, you can purchase a separate one and use it to control the humidity level in the room.

It may very well be operating properly. One way to tell is to buy an inexpensive humidity gauge and check to see what the humidity level in the room is. (You rarely need extra humidity when the outside temperature is above 32°, and usually not until it drops into teh teens.)
Here's one you can pick up for $10 on Amazon.

It depends on how humid it is in the conditioned space, how well sealed the conditioned room is, and how high you have the humidifier set. If you have low humidity in your conditioned space and you are asking for a higher humidity number, it could go through quite a bit of water. If your room is not sealed well, it will allow lower conditioned air into the room and put a larger demand on the humidifier

If your "tap water" is from a well, the humidifier may be clogged with mineral scale. Even if it is not well water, your municipal source may have a high mineral content.

Using a 50/50 solution of White Vinegar and water run through the system will usually clean the mineral scale out. In the future, I would recommend that you use Bottled Distilled Water. You can buy it by the gallon, inexpensively at grocery stores or pharmacies.

is it possible that you have the mist turned up too high? If the room is very small, the high setting could be providing too much humidity to the room. I'm thinking that the paint crackled as the humidity climbed.

Buy a new filter cartridge. www.ventahumidifiers.com

what country are you in... winter time is low humidity to begin with.

Robert

I would say that the beauty of steam is that it has to get through the 100 degree temperature to leave the aqueous state - i.e. to move from a liquid to a gas.

The benefit of that is that any organizums in the water should be killed as a result of that process. Its possible that it smelt musty or old stagnant water smells but to be honest there is little change of harm to the little ones.

Best wishes