Aprilaire 700 SERIES Technical specifications

Maintenance Instructions:
Aprilaire Models 700, 700A, 700M, 760, & 768
1. Note Humidifier Control setting and turn dial to the “OFF” position.
2. Disconnect electrical power (9) and turn off water supply.
3. Unlatch humidifier front cover assembly (1) from base assembly (2) at the
bottom of the cover, lift, and set aside.
4. Pull out the water panel evaporator assembly (3) by grasping at the top and
tipping out.
5. Unsnap the distribution tray (4) from the scale control insert (7). Follow the
instructions below depending upon the type of distribution tray in your
humidifier.
a. For trays with a synthetic fabric liner: Lightly scrape out or brush off
any mineral deposits, being careful not to stretch or loosen the
synthetic fabric liner. Soaking the tray in vinegar or a lime-removing
agent is helpful when trying to remove stubborn mineral deposits.
b. For trays with granular coating: Do not scrape off the granular
coating, but lightly scrape out any mineral deposits and clean the “V”
notches (5). This textured surface helps ensure even water flow for
maximum performance. If the granular coating has been removed,
place several drops of liquid dishwashing soap on the distribution tray.
This will only need to be done once if there is no granular coating.
6. Slide the Water Panel evaporator (6) out of the scale control insert (7). Clean
the scale control insert of mineral deposits. Slide the new Water Panel
evaporator into the scale control insert with the colored spot up and snap the
distribution tray (4) back into place.
7. Inspect the plastic feed tube (plastic only) by gently flexing it and looking for
cracks or signs of water. Replace tube if it is cracked, brittle, or has been
damaged.
8. Reinstall the Water Panel evaporator assembly (3) into the humidifier by
fitting its drain into the round receptacle at the base of the humidifier. Push
the assembly in at the top between the retaining ribs that hold the assembly
in place in a vertical position.
9. Remove the drain line (8) from the bottom of the humidifier. If applicable, flex
it to loosen any mineral deposits or blockage. Then flush it with water under
pressure. If it does not clear, replace it. Slip the drain line back onto the drain

fitting. Make sure the drain line has a constant downward slope and is not
flattened or blocked.
10.Reinstall front cover assembly (1) by hooking at the top of the base assembly
(2) and latching at the bottom.
11. Reconnect electrical power (9) and turn on the water supply.
12.Check system operation:
a. Automatic Humidifier Control: (Automatic or Manual mode) Check
system operation by turning the knob to “Test.” With furnace blower
operating, humidifier will operate for one minute. DO NOT LEAVE IN
TEST MODE AS HUMIDIFIER WILL NOT OPERATE. For Controls with
Change Water Panel indicator light, turning knob to “Test/Reset” will
reset Change Water Panel indicator.
13. Set Humidifier Control to its original position.