In some installations, dirt or other debris may be blown into the
unit from the outside and settle in the base pan (the bottom of
In some areas of the United States, a naturally occurring
“gel-like” or “slime-like” substance may be seen in the base pan.
Check it periodically and clean, if necessary.
On 4500 Series models, do not remove the rubber drain plug
from the basepan. If removed, excess water may drain to the
The coils on the outdoor side of the Zoneline should be checked
regularly. If they are clogged with dirt or soot, they should be
cleaned by either low or no pressure cleaning methods. Ensure
that electrical area/devices are protected during cleaning. You
will need to remove the unit from the wall sleeve to inspect the
coils. The dirt buildup occurs on the fan side of the outdoor coil.
Clean the outside coils regularly.
Room Cover and Case
Turn the Zoneline off and disconnect the power supply. To clean, use water and a mild detergent.
Do not use bleach or abrasives. Some commercial cleaners may
damage the plastic parts.
Make Up Air Models (not on all units))
The make-up air ventilation system is designed to condition air
cycled through the vent door and into the room. In addition to
providing fresh air, it dehumidifies incoming air when it is above
55% relative humidity.
The make-up air ventilation system is operated by a switch
located on the front of the electrical control cover under
the Zoneline room front. The system is turned on and off by
depressing the on (I) or off (O) button as shown in the illustration.
Should the Zoneline need to be operated as a PTAC or PTHP only,
the following steps should be followed:
1. Order service PN# WP76X21320
2. Unplug the Zoneline
3. Remove the room front
4. Turn off the ventilation system by depressing the on/off
button so that off (O) is selected (see above illustration for
5. Pull the Zoneline from the wall sleeve and install
service PN# WP76X21320 as shown in the illustration.
6. Push the Zoneline back into the wall sleeve and restore
power to the unit.
Care and cleaning