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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 7537
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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I need help with hooking up Honeywell Humidistat to my

Customer Question

I need help with hooking up Honeywell Humidistat to my current Honeywell Thermostat..What wires do I hook up
Submitted: 2 months ago.
Category: HVAC
Expert:  Phil replied 2 months ago.

Hello, I need the model number of the thermostat you have. (its stamped on the back of the thermostat after you pry it from its sub base)...

and the brand and model number of the humidifier.

We can go from there.

Customer: replied 2 months ago.
Honeywell Thermostat - Model #TH8321U1006Honeywell Humidistat - Model # H6062A1000
Expert:  Phil replied 2 months ago.

Thanks, ***** ***** to know the brand and model number of the humidifier itself, that is because depending on what you have, the wiring from the humidistat to the humidifier itself will change.

Customer: replied 2 months ago.
Where is that located as I am not sure
Customer: replied 2 months ago.
Also, cant i just run wire directly from thermostat to humidistat using the current wires in the wall for the thermostat?
Expert:  Phil replied 2 months ago.

Hello, you have the more advanced communicating electronic control system, there is nothing simple about it...but yes we might end up just running two wires from the new humidistat to the humidifier or the thermostat. For me on this end it will require a hour to study what you have and how it is wired to your furnace, and how the dip switches are set and the thermostat is programmed in order to define the wiring.

It is complex. and that is me talking, 75 years old and 56 years in the business. Doing it myself onsite is a one hour job, most contractors will want to charge you 2 to 4 hours to do it on site.

Doing it by remote control from here usually takes some time.

Customer: replied 2 months ago.
can i just give you the color wires from the wall and you can tell me how to hook them up from new humidistat directly to the thermostat?
Customer: replied 2 months ago.
Right now the thermostat is hooked up as follows...Pink Wire = RC
White Wire = W
Yellow Wire = Y
Green Wire = G
Blue Wire =Y2
Customer: replied 2 months ago.
Here is the wire codes on back of Humidistat..C
Expert:  Phil replied 2 months ago.

Thanks, ***** ***** me you have a conventional non communicating system, with a gas or electric furnace (not a heat pump)

That should be the manual. Notice all the red ink about what it takes to install just the thermostat.

You would use W and C on the thermostat to send 24v power to the humidistat whenever the system is in heating mode. then the humidistat will close contacts that control the humidifier whenever the humidity drops below the set point.

Without the humidifer model number however I am not able to define that circuit.

Expert:  Phil replied 2 months ago.

Just in case there is some confusion. The humidistat does not do any humidification. it just controls a humidifier that does the humidification.

The humidifier depending on brand and model is 14 x 18 x 10 inches in size or larger, and most mount on the discharge air supply from the furnace.... there are also free standing models. ... and steam injection models, duct mounted and or free standing.

Expert:  Phil replied 2 months ago.

Depending what the local humidification requirements are you may or may not need the more expensive steam humidifier to do the job.

Customer: replied 2 months ago.
Do I just keep all the wires hooked up to the thermostat as is and just use a jumper wire and use the W and C from the thermostat ? and what letters do they hook up to on the humidistat?W = ?
C = ?
Expert:  Phil replied 2 months ago.

Leave all of the wires connected to the thermostat, just add wires from C to C on the humidistat, and R or W on the thermostat to R on the humidistat,

Let me know if you have any questions. This assumes that you have the model number of humidifier shown.

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