Carrier Humidifier Owner's Manual page 5

The humidifier pad, designed especially for uniform, high
evaporation, and the Scale Control Insert also efficiently trap mineral
deposits which are often the cause of damage to working parts in
ordinary humidifiers. No "white dust" can be distributed throughout the
living quarters. The humidifier pad must be in good condition to assure
high capacity trouble-free performance, tt should be changed annually
with the exception of the Water Saver humidifier which should be
replaced at least twice per heating season.
Older design water distribution trays have a granular coating in the
bottom of the distribution tray to provide equal distribution of water to
each of the openings assuring an even flow over the humidifier pad. De
not clean the mineral scale off the bottom of the water distribution tray
at the end of the humidification season. If the granular coating is
removed, it is not necessary to purchase a new distribution tray You
can accomplish the same uniform performance by applying a small
amount of liquid dishwashing soap over the entire inside surface of the
water distribution tray. This will allow the water to flow evenly through
each ofthe openings, provided the humidifier is level, in order to
achieve maximum capacity.
The current distribution tray which incorporates a synthetic fabric
liner that replaces the granular coating, is designed to deliver water
uniformly over the entire top surface of the humidifier pad, provided it is
mounted level, it is normal for some mineral deposits to form in the
distribution tray as it dries out between humidification cycles. These
deposits can actually help distribute water in the tray, but if they form
enough to block the openings, they should be removed as described in
the "Periodic Preventative Maintenance" section of this manual.