Heating, Air Conditioning, Fridge, HVAC/wiring


QUESTION: Hi Jim, So the location and plumbing are covered, on to the hard part for me. I have to mount the humidstat, outdoor sensor, humidifier, transformer and furnace wiring,

The humidstat mounting is simple
The outdoor sensor wires into the humidstat input ODT. I have some copper speaker wire that is larger, can I use this and is there a right/wrong way (hot/neutral)?

The humidifier has a white and yellow wire. Looks like the white wire hooks into humidstat output H with 22 awg copper wire?
The yellow wire goes to the transformer, hooks into one of the two screws, then do you take another piece of 22, hook into the other screw on the transformer and wire into the humidstat output H?

Transformer...Needs to wire into a power source?

ANSWER: Linda, I wouldn't use the speaker wire, 22 is not heavy enough. I would use thermostat wire, two conductor #18. The ODT sensor is not polarity sensitive so it doesn't matter which wire you tie to.

Did the transformer come with the humidifer? Does you model come with digital humidistat?

---------- FOLLOW-UP ----------

QUESTION: Yes, the transformer came with the humidifier. On the wiring diagram for the furnace it says something about a hookup for a humidifier, not sure what that means. I do have a digital humidistat that has an outdoor sensor.

ANSWER: Yes, if look half way down and on the left on the diagram it says humidifier 24v. The terminals will be marked C and H. You won't need to use the transformer supplied with humidifier. Run H wire to H on stat. Run C wire to one of the wires on the water valve, it doesn't matter which one.

---------- FOLLOW-UP ----------

QUESTION: So I run 22 awg wire?  Furnace to humidistat, H to H...output
         Furnace to humidifier,  yellow wire to C
         Humidistat to humidifier, white wire to H..output

If this is correct we can move onto humidistat to furnace.
What size wire do I need for this application, how many strands?

humidistat to furnace...power...R to R
         input   ODT-sensor- #18
         W to W1 or W2 ?
         output  H to H furnace
         H to humidifier white wire

That made my head hurt..LOL

Good Morning Linda, Use #18 wire on all the wiring. As long as you use #18 wire the strands
won't matter. Ok,your good to go on the first paragraph. If I remember right you said there is only 2 wires from the stat. So we will have to vary from the diagram.

R to R
C to C
Sensor to ODT
W1 to W
We won't be using the G terminals. I could go into an explanation, but this would make your head hurt again lol. So let's skip that.  

Heating, Air Conditioning, Fridge, HVAC

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Jim S.


I can answer questions on gas or electric furnaces, ac units and heat pumps. I don't work on boilers,chillers,or home appliances.


I have been in the HVAC trade for over 35 years. For the past 15 years I have owned my own business. I am semi-retired so I can answer questions in a timely manner.

I attended trade school for 5 years on weekends and evenings. This was very hard to do, but well worth it!

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