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Maintenance Instructions for Aprilaire Models 700, 700A, 700M, 760 & 768

Instructional Video Below:

  Maintenance Instructions for 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.

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.

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 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:

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.