8 5
InstallationMaintenance
To Inspect and Replace the Evaporator Pad:
It is recommended that the evaporator pad in the humidifier be replaced annually to
maintain efficient operation. However, more frequent replacement may be necessary in
areas of poor water quality.
1. Disconnect the power supply to the furnace.Turn OFF the water supply at the saddle
valve by turning the valve handle clockwise.
2. Fully loosen the thumb screw at the bottom of the unit cover. The screw will remain
attached to the cover. To remove the cover from the duct, pull the bottom away and
then lift up. Put the cover aside for reassembly.
3. Remove the water distribution tray, located above the evaporator pad. It is held in place
by a snap that must be lifted to pull out the tray.
4. Pull the evaporator pad and frame assembly away from the duct, being careful not to
disturb the drain connection. Remove the old evaporator pad and discard.
5. Inspect the interior of the humidifier and remove any mineral deposits and accumulation
from the frame assembly and drain tray.
6. Remove the new evaporator pad from the plastic bag and insert into the frame assembly,
with the black spot facing up. Ensure that no part of the evaporator pad is outside of
the frame. Return the evaporator pad and frame assembly to their original position
inside the humidifier.
7. Check the distribution tray to ensure that holes are clear of any scale build up. If desired,
the distribution tray can be washed with mild detergent and warm water.
8. Replace the distribution tray making sure the snap is hooked over the outside edge of
the tray. Replace the cover and secure by tightening the thumb screw. Turn the water
back on and reconnect power to the furnace.
End of Heating Season Shut Down:
1. Inspect and clean humidifier and components.
2. Turn water supply off at the solenoid valve.
3. Turn humidistat off.
4. Close the bypass damper if installed.
Read the instructions in the furnace installation manual carefully before attempting installation
or operation of the humidifier. Failure to follow these instructions may result in improper
installation and therefore, void the manufacturer’s warranty.
WARNING
Improper electrical wiring can cause personal injury, death, or
property damage. Local codes require that the unit be installed
by a properly qualified HVAC technician or electrician.
Some furnaces provide 120VAC auxiliary terminals that may be used to power the humidifier.
Since these auxiliary terminals are interlocked with the fan, no separate fan interlock relay is
required in the humidistat circuit depending on the furnace model. These terminals are
marked HTG.Acc/Neutrals. Acc/Neutral or Hum-H/Hum-N.
When connected to these furnaces using 120VAC auxiliary terminals interlocked to the furnace
fan, connect the primary of the supplied 120/24VAC transformer to the auxiliary terminals on
the furnace. Connect the secondary of the transformer to the unit pigtails and SPST humidistat
provided. The humidifier will then turn on whenever the furnace fan is running and there is a
call for humidity.
For systems without 120VAC or 24VAC auxiliary terminals, systems with multi-speed blowers or
non-120VAC systems, the switch contacts of a separate SPST-NO fan interlock relay is required
to be wired in series with the humidistat switch. Depending on the installation and furnace
manufacturer the coil for this relay could be:
• Wired in parallel with the coil of the NO fan relay, typically 24VAC.
• Wired in parallel with the common and heating speed tap of the units blower typically
120VAC or 240VAC.
• An inductively coupled current sensing relay on the common of the units blower.
See installation instructions on the provided
mounting template