Installation on Return Air Duct
CAUTION: Mount the humidistat on the return air duct only.
Installation on the warm air duct will destroy the humidistat element.
1. Position the humidistat in the return air duct at least 10 in.
(30.48 cm) upstream in front of the humidifier or the humidifier
bypass tube.
2. Remove the backing from the humidistat template and attach the
template in a horizontal position. Make sure it is level.
3. Drill four 7/64 in. (0.28 cm) mounting holes in the duct as indi-
cated by the template.
4. Drill a 1/2 in. (1.27 cm) hole in the center of the template. Use
tin snips to cut the rectangular hole indicated by the dotted lines.
Remove the template.
5. Remove the adhesive backing from the gasket and affix it
around the opening.
6. Connect the low voltage wires to the humidistat terminals. Tuck
the wire into the recessed area on the back of the base plate.
CAUTION: Make sure the wires are securely tucked into the
slot under the mounting base.
7. Use sheet metal screws to securely fasten the humidistat to the
return air duct.
Return Air Duct
Screws
Humidistat
FIGURE 1: Duct-Mount Wiring Diagram
Recess on
Back of Base
Gasket
Wire
2