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Aprilaire Model 700 Humidifier
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Click here to see all parts for the Aprilaire model 700 humidifier

Click here to see Instructional Video on Aprilaire model 700 humidifier

Note - The Aprilaire model 700 humidifier is equivalent to the model 700A

The Model 700 power humidifier features truly automatic control, so there's no need to ever manually control the humidifier. It is also designed with ease of service in mind. It utilizes an outdoor temperature sensor for monitoring even the slightest changes in outdoor temperature. This high-tech humidification system can deliver up to 50% more moisture in comparison to competitive units. With flexibility in mind, it can even be installed in manual mode if necessary. Complementing any HVAC system, the 700 has an evaporation capacity of 0.75 gallons per hour, among the highest capacity humidifiers sold. If you own a larger home and want the best, then this may be the humidifier for you, as it will handle up to 4,200 square feet if your home is tight in construction. Plenum opening size is 14 7/8" W x 14 3/16" H. Because this powered unit does not require extra bypass ductwork - it can be easily installed where space is at a premium.

Note: The model 700 is not suited for systems with horizontal air flow.

Included with unit:
  • 1 installed # 35 Water Panel
  • Self-piercing saddle valve 
  • # 60 automatic humdistat with outdoor sensing bulb 
  • 110 VAC to 24-Volt Transformer
  • Installation instructions/plenum cut-out template 
  • Owners Manual
  • Free digital hygrothermometer redeemable through factory product registration
Humidifier installation will require the following supplies (not included): 

  • #8 sheet metal screws 
  • 1/4" copper water line 
  • 1/2" ID clear vinyl tubing for drain 
  • Small wire nuts 
  • 18-2 thermostat wire 
  • If furnace circuit board does not include humidifier accessory terminals - an Aprilaire #50 Current Sensing Relay will be needed.

What is the difference between the 700M and 700 models?
The new 700 model includes a new # 62 automatic digital control.  The 700M includes the manual control.

Does the outdoor sensor need to be installed in order for an automatic humidifier to work?
If the humidifier control is installed and is operating in the automatic mode (as referenced by the faceplate on the humidifier control) the outdoor sensor is required for proper operation. The sensor is the component which sends the temperature reading back to the humidifier control and allows it to adjust the humidity level in the home accordingly.

How often should I replace the water panel?
For the best performance we recommend the water panel on most of our humidifiers be replaced once a year, either prior to the start of or at the end of the heating season. (Model 400 should be changed twice during the heating season.)

Why is there water draining from my humidifier?
All of the Aprilaire flow-through humidifiers incorporate a self-flushing action. This action flushes down the drain many of the mineral deposits left on the water panel from the evaporation process. This also minimizes the amount of maintenance required

How much water should be flowing out the drain of my humidifier?
The water going out the drain line serves the important process of flushing the minerals from the water panel. Depending on the model that you have in your home, it should take two and a half to five minutes to fill a one-quart jar. The actual time is determined by the water-metering orifice in your humidifier. If your humidifier has a yellow or white orifice it will take approximately five minutes to fill a quart jar and if it has a blue or red orifice it will take approximately two and a half minutes to fill a quart jar.

Should I regulate the water flow to my humidifier at the saddle valve?
No. The saddle valve is not designed to regulate the water flow. The humidifier has a water-metering orifice that is designed to regulate the water flow to the water panel.

Should our humidifier be connected with hot or cold water?
All of our flow-through units as well as our Model 400 humidifier can be connected to hot or cold water. Hot water increases the evaporative capacity of your humidifier, provides more humidity to the home and offers more flexibility in the operation of the humidifier. We would recommend that if our power units are installed on the return ductwork, that they be connected to hot water, as this is their only heat source. With any drain-through Aprilaire humidifier connected to hot water, the heat in the water is used in the evaporation process and the water coming out of the drain will be cold to the touch.

Should we use soft water or hard water?
Aprilaire offers total flexibility in the installation of our humidifiers in that they will operate properly with either hard or soft water. Connecting to hard water may leave mineral deposits on the water panel that are scaly and hard in nature. Connecting to soft water may leave mineral deposits that are fluffier in nature. The bottom line is the water panel will typically last a full heating season using either type of water.

Should the humidifier be installed on the return (cold air) or on the supply (hot air) ductwork?
Any of our furnace-mounted units can be installed on either the cold air or hot air ductwork. We do recommend that if a power unit (#700) is used and is installed on the cold air ductwork, it be connected to hot water to maximize evaporation.

Will my Aprilaire Humidifier affect my Aprilaire Air Cleaner?
The Aprilaire humidifier uses a natural evaporation process to generate humidity. Because the humidity is a gas it passes through any air cleaner with no adverse effects.

What causes condensation on my windows and how can I eliminate it?
Cold air outside your window cools the air just inside your window more that the air in the rest of the room. If the well-humidified air just inside the window cools too much or too quickly, it can't hold as much moisture as before and water appears on the window. To eliminate this, Aprilaire has created the #62 automatic control, which always maintains proper levels of humidity with no adjustment needed.

How do I properly install my replacement Aprilaire Water Panel?
The orientation of your water panel is important for maximum evaporation. Most genuine Aprilaire Replacement Water Panels you purchase will have a paint dot on one of the short ends. This paint dot should be placed up, towards the water distribution tray, for proper operation. If your humidifiers requires the #45 water panel, there will be no paint dot and the panel can be installed in either orientation.

5-Year Manufacturer's Warranty
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