Humidistat problems This is my second Honeywell HCM 305T (black) humidifier. I cannot seem to figure out why the unit cannot maintain a certain level of humidifier as specified by the manufacturer. This unit is supposed to automatically turn on/off. Does anyone have this problem or know how to solve it?

The ability of the humidifier to maintain a given moisture content in the air is far more difficult than a heat or cooling unit to heat or cool the air.

Moisture vapor has far more energy to seek dryer air, than tempered air. So the moisture seeks and finds dryer air quickly, whether it be through stair and door ways, or through cracks and seams in walls and doors/windows, or through non vapor barrier surfaces.

The only way the unit would be able to achieve a humidity level as stated, is for the unit to be placed in a vapor-tite room that has a minimal of leakage.

You could put more humidifiers in the space, or more and larger humidifiers in the space, to try and overcome the vapor moving to other areas of the space. But unless you have a fairly vaportite space, it is unlikely the unit is under capacity, and the only way to test what capacity is needed is to take humidity measurements.

Reply back with any questions you may have.