Honeywell DG115EZIAQ TrueIAQ Digital IAQ Control Reviews

Posted On September 15, 2015 at 6:33 pm by / No Comments

Honeywell DG115EZIAQ TrueIAQ Digital IAQ Control

Product Features

  • Setting changes can be made easily with the touch of a button
  • Manages humidification, dehumidification, ventilation and bathroom fans from a central point in your home
  • Simultaneously displays both indoor and outdoor temperature and humidity levels on-screen. Automatically adjusts inside settings based on outdoor conditions
  • Include individual air quality enhancements to your system with TrueIAQ, or integrate them all as part of a total air quality system
  • Intuitive digital backlit display

Product Description


List Price: $ 120.17

Savings: 71.26

Your Price: [wpramaprice asin=”B0017OCEBQ”]


Customer Reviews

16 of 16 people found the following review helpful
5.0 out of 5 stars
Ideal for Certain HVAC Applications, October 29, 2013
Verified Purchase(What’s this?)
This review is from: Honeywell DG115EZIAQ TrueIAQ Digital IAQ Control (Tools & Home Improvement)

I chose this Honeywell device over an Aprilaire automatic (digital) humidistat and the first impression after installation is very favorable. The deep discount in pricing makes the Honeywell a solid contender even if just used for replacing an outdated manual humidistat. This was my situation. If you’re planning to do something similar, read on.

1. Three “dry output” relays which can be used to switch 24VAC @ 1 Amp maximum to independently control:
a. Humidifier
b. Dehumidifier
c. Vent
2. Large digital readout of indoor temperature AND humidity simultaneously displayed with outdoor temperature AND humidity. These four figures are available at a glance with no button pushing. The Aprilaire contender did not have an outdoor humidity sensor.
3. The control unit may be mounted on the return duct or has the flexibility to be wall-mounted. If you don’t mind running some “thermostat wire” a wall-mounted installation puts the controls right in your living room with the added bonus of an outdoor thermometer and hydrometer. Plus a digital clock. Very slick.
4. The device can programmed to initiate a HVAC fan request when humidification or dehumidification is required. This is a VERY IMPORTANT feature as I will explain below.
5. The device’s Window Frost Protection feature throttles back humidification levels as outdoor temperatures drop. The amount of throttling is user selectable depending on how tightly your house is built.
6. All settings are saved in non-volatile memory so no backup batteries are required. The clock will retain time for up to four hours after power failure.
7. The device is loaded with “Service Timers”. These are simply reminders to change things like water panel, air filter, vent filter, UV light. Each one has a unique display icon which illuminates. Might be helpful to some while others may just find it needless gimmickry.
8. Plenty of software programmable settings accessible by a “service menu”. For example, the vent relay can be programmed to activate a ventilation fan between certain hours of the day. Check the “Advanced Programming” section of the owner’s manual for complete list.
9. The outdoor “sensor” is actually much more sophisticated than a simple “probe”. It is a second circuit board in a weatherized enclosure which communicates with the host controller via a 2-wire digital bus.
10. The LCD display is back-lit and illuminates when a front panel button is pressed.

1. The owner’s manual (which contains installation instructions and sample wiring diagrams) is terse but adequate for someone with a little HVAC knowledge. The installation portion was written for the HVAC technician not the first-time handyman. However, armed with the right background the unit is very easy to install. Especially if all you want to do is replacing an existing manual humidistat. You can’t beat the price.
2. The desired humidity level may only be set in 5-unit increments, i.e. 35%, 40%, 45% etc. This may not be a “con” but it should be pointed out.
3. No wire is provided, just the necessary mounting hardware. Probably makes sense as each installation is different.

That’s pretty much the review. For additional information on using this device as a dedicated automatic humidistat, read on:

I chose to mount my Honeywell controller on the return duct simply because that was the easiest method for running the wires. I used a 2-conductor 18 gauge thermostat wire to connect the outdoor sensor and ran the wire through the same wall opening as the A/C refrigerant lines (do not mount the sensor on the sunny side of the house). A 2-conductor cable was also used to wire the “humidifier” switching relay (in series) into the existing 24-volt humidifier solenoid circuit. I actually left the existing manual humidistat alone (didn’t want to repair the wall after removal) and simply set it “on” so it functions as a high limit switch.

The final connection was 5-conductor cable to the furnace control board. Only 3 conductors were required. You will need to connect the Honeywell to the R and C terminals (for 24 AC power). Finally, and this is the beauty of it, the HVAC fan request (3rd conductor) from the Honeywell was wired to an unused “low voltage” fan speed input on the furnace’s Genteq Evergreen ECM blower motor. This allows the Honeywell to “step up” the blower fan to its own speed when humidification is required, even if there is no call for heat at the time. Be sure your humidifier is connected to the hot water supply (not cold) otherwise there won’t be much evaporation.

If you have an older style blower motor, then it may be necessary to wire the fan request to the G input at the furnace, or configure the Honewell to wait until the fan is sensed before activating the humidifier relay.

When you…

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9 of 10 people found the following review helpful
4.0 out of 5 stars
Highly functional unit with temperature errors, January 6, 2012
Verified Purchase(What’s this?)
This review is from: Honeywell DG115EZIAQ TrueIAQ Digital IAQ Control (Tools & Home Improvement)
I got this unit to monitor humidity inside an enclosure in a laboratory. It works quite well for this purpose and the humidifier control functions as advertised to allow some active control. From a cost standpoint, the unit is a real bargain even if it is only used as a 2-point humidity meter. The only drawback to the unit I received was that there is a 4 degree F temperature offset in the readings (it reads low). Since the unit has a temperature offset adjustment, it is straightforward to correct this error in the unit. Nonetheless, I would not expect a unit like this to exhibit an error of this magnitude out of the box.


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9 of 11 people found the following review helpful
2.0 out of 5 stars
No information, no support, no warranty from Honeywell., November 10, 2013
Steven Martin (Northfield, MN United States) – See all my reviews

Verified Purchase(What’s this?)
This review is from: Honeywell DG115EZIAQ TrueIAQ Digital IAQ Control (Tools & Home Improvement)
To reply to another review here: This unit will do over 40% RH. You need to go into the "Advanced Programming" section , down to item #20, and change the value from the default 40% Humidity High Limit. It will go up to 80% in 5% increments.

I would not recommend that the common home owner purchase the Honeywell DG115EZIAQ. You will get absolutely no information from Honeywell about the unit other then what you can read for sales info. If you do a search, you can find a PDF download of the manual that comes with the DG115EZIAQ. Read the manual and if you completely understand the connections and programming, then you are good to go. If you do not understand any part of the wiring or have any questions about the programming, DO NOT BUY THIS.

I work with HVAC commercial products in a manufacturing environment, doing equipment support. I do not have any problems understanding the wiring. My question is about the programming and the CFM Setting on line 150. I wanted to know what CFM is the program looking for, the CFM of my HRV or the CFM of the ASHRAE calculations for my home. I sent an e-mail to Honeywell and after 4 days with no reply, I called Honeywell. I later got a response to my e-mail but both the e-mail and the phone call came to the same out come. Here is Honeywell canned answer:
"Thank you for contacting Honeywell.

First I’d like to apologize for the delayed response.

The DG115EZIAQ is one of our trade model control units and should be set up and maintained by a licensed professional. I do not have the necessary documents on this product to be able to tell you how it would need to be set up for your system and needs. I’d be happy to look up a few contractors in your area to help you out."

Honeywell makes the product but can not answer a single question to clarify what the programming is looking for. If you are not signed up as a contractor selling Honeywell products, you will not get any more information about this product from the manufacture Honeywell. Honeywell’s help line is only to refer you to contractors that have signed up with Honeywell. The unit also has a 5 year warranty but only if it is installed by a Honeywell contractor is what they told me. It looks to be a good product but has no support for the home owner.


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