# Honeywell IAQ Wiring



## hugginsg (Feb 1, 2009)

I replaced my old Honeywell thermostat with a new VisionPro IAQ thermostat. I am a little confused on the wiring so I will lay it out with what I have and what I think should be wired from the furnace to the interface IAQ module. 

My current furnace is a Carrier WeatherMaker Infinity Model 58MVP100-20 gas furnance with a Carrier AC unit and an AprilAire 700 Humidifier currently hooked up.

Current hookup from existing furnace to thermostat & humidifier:


Infinity Current Thermostat
W2-jumpered with W/W1 
Common Blue wire - to humidifier
W/W1 White wire - to Thermostat
Y/Y2 Yellow wire - to Thermosat
R Red wire - to Thermostat
G Green Wire - to Thermostat
Hum Black Wire - to humidifier

After I hook up the three wires from the thermostat to the interface module I think that the existing wires from the furnace and humidifier should be hooked up to the interface module as follows:

Infinity IAQ interface module 

W2-jumpered with W/W1 
Common To Common
W/W1 To W1
Y/Y2 To Y
R To R (maybe to RC & RH also)
G To Green

AprilAire 700 To HUM 1 & 2 

Am I way off base here? Any responses would be appreciated.

Thanks in advance,

Greg


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## Dr Heat (Jan 14, 2009)

yes that should work 

Jump R RC RH these need to have the jumper

You do not need to jump W1 and W2 just set the stat to single stage.


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## hugginsg (Feb 1, 2009)

*AC Unit Hookup*

I guess that I forgot to put in one additional hookup to the IAQ which was the AC unit.

The current AC unit has two wires which are indicated below and their connection to the current furnace/thermostat wires:

AC unit Red wire to Y/Y2 on furnace
AC unit White wire to C (24 V) on furnace thermostat 

Should these two wires be hooked up to the appropriate connections on the IAQ unit? I am not sure if there is suppose to be 2 wires to the same connection on the IAW unit so any help would be appreciated. 

Thanks in advance.


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## beenthere (Oct 11, 2008)

Y1 from the IAQ should be already hooked to the Y/Y2 terminal on the Infinity.
So the wires from the outdoor unit just hook to the C, and Y/Y2 of the furnace.


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## hugginsg (Feb 1, 2009)

*Little confused*

I am still a little confused. 

If I understand you correctly what you are saying is that I should take the white wire from the AC unit and also hook it to the "C" terminal on the IAQ unit which would have two wires connected to it: 1 from the furnace and 1 from the AC unit. Is this correct.

The red wire from the AC unit would be connected to the "Y" terminal on the IAQ which would also have the yellow wire from the furnace attached to it so there would be two conections to the "Y" terminal: one from the furnace and one from the AC unit?

I am assuming that if there is only a Y and a Y2 on the IAQ that when you say Y1 you are refeering to the Y terminal on the IAQ?

Thanks


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## beenthere (Oct 11, 2008)

The wires from the A/C unit connect to the furnaces C and Y/Y2 terminal.

The IAQ's Y1 connects to the furnaces Y/Y2 terminal.

I'm not sure what wire designation your furnace has for its A/C terminals.So thats why I type Y/Y2.


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## hugginsg (Feb 1, 2009)

The C on the furnace already goes to the C on the IAQ
The Y/Y2 (only one terminal on the furnace) already goes to the Y on the IAQ

So I guess I am confused why the AC wires would go to the furnace C and Y/Y2 connections 
when these wires are already hooked to the C and Y on the IAQ.

On my Infinity the connections are:

W2 C W/W1 Y/Y2 R G HUM (The W2 on the infinity is jumpered with the W/W1 connections on the infinity)

I was going to make the connections to the IAQ as follows:
W/W1/W2 (all jumpered) on furnace to W1 on IAQ
C on furnace to C on IAQ
Y/Y2 on furnace to Y on IAQ
R on furnace to R on IAQ
G on furnace to G on IAQ

C on AC to C on IAQ
Y on AC to Y on IAQ

I guess what I am confused on is when you say "The wires from the A/C unit connect to the furnaces C and Y/Y2 terminal." The furnaces C and Y/Y2 are already connected to the IAQ C and Y1 so do the C and Y wires from the AC unit connect to the furnaces C and Y/Y2 or the IAQ's C and Y terminals?

Thanks


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## hvaclover (Oct 2, 2008)




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## beenthere (Oct 11, 2008)

The A/C wires connect directly to the furnace.

The IAQ's wires will be connected to the same location on the furnace.

You use the furnace terminals for both their function, and as junction terminals. The IAQ's terminals don't have a lot of room.


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## hugginsg (Feb 1, 2009)

Ok, I get it now.

Currently all of the wires originate in the furnace with only one wire on each of the furnace connectors on the furnace panel and are terminated outside of the furnace with their respective wires to the thermostat and humidifier.

So instead of using the terminals on the furnace as a junction box I should just be able to connect the appropriate wires together outside the furnace and then terminate one wire to each of the appropriate IAQ connectors?

Is it more professional or an industry standard to use the furnace connectors as the junction box instead of making all of the connections outside the furnace using wire nut connectors to connect the appropriate wires or is it just a matter of preference? 

Thanks


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## beenthere (Oct 11, 2008)

Looks better if all the wire junctions are in the furnace.
Instead of just outside the furnace.

I think it looks much better and is more professional if the terminals are used for junctions instead of wire nuts. 
With the exception, that if you have 3 or more wires to go to a terminal, you should use a wire nut and pigtail connection then.


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## hugginsg (Feb 1, 2009)

Thanks for all of the help. I am going to do the installation tomorrow and see how it goes now that I am confident I know where everything goes.


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## hugginsg (Feb 1, 2009)

I hooked up the thermostat this morning went into the installer mode and set up each item. I went into the installer test mode option and the AC and heating appears to be working with no error codes generated. During the heat test the furnace turned on and went into the higher fan mode. I currently have the fan on "ON".

However, I am now getting an error code of 44 on my Infinity Furnace (4 green, 4 Amber): *Blower Calibration Fault* - Indicates the calculated blower speed is below 250 or above 1300 RPM. Unit will default to low or high heat mode if possible. If this fault occurs in conjunction with fault #41 check wiring to motor otherwise refer to the trouble-shooting guide. If this fault occurs by itself check for undersized ductwork, or excessive static caused by a dirty filter, or closed registers.

I did not get this error previously.

Any help would be appreciated.

Thanks,


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## beenthere (Oct 11, 2008)

Check to make sure you didn't pinch or loosen any factory wires.

Could be a loose molex plug for the blower.


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## hugginsg (Feb 1, 2009)

I checked the filters and the pre filters on my electronic air filter were very dirty. I took them out and cleaned them along with the cells and the Infinity error code has gone away with the fan on constant. The error code may have been there when I turned off the furnace to make the new thermostat connections. Anyway I believe that the problem is solved.

Now I have to hook in my Aprilaire 700 humidifier and I thought I had it figured out but now I am not so sure. 

I am not sure how the IAW module hooks up to the Aprilaire 700 control panel. The IAQ has HUM 1 and 2 connections on it.

The Aprilaire control panel has R and C connections which require 24 volts and two H connections which go to the brown wires on the humidifier. The furnace has HUM and C which both supply 24 volts so I am assuming that these go to the R & C connections on the Aprilaire control panel. Without using the IAW I think that the two Aprilaire brown wires would go to the two H connections on the Aprilaire control panel.


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## beenthere (Oct 11, 2008)

That HUM terminal may be to slow the blower for dehumidification.
It usually is on VS blower systems.

If you want to be able to add humidity weather or not the furnace is in heating your house.
Connect teh Aprilaire R and C to R and C of the furnace.
Then hook the 2 low voltage wires from the humidifier to the 2 HUM terminals of the IAQ.

Then set it up to humidifiy anytime, or only when there is a heat call.


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## hugginsg (Feb 1, 2009)

I thought that I had read somewhere that when the IAQ is used that the Aprilaire humistat does not need to be used as the IAQ has built in humidity control.

If I do what you say I am assuming that you are using the Aprilaire humistat to connect to the R & C from the furnace and then running the two brown wires from the humidifier to the Hum 1 and Hum 2 on the IAQ. What is controlling the humidity the IAQ or the Aprilaire? Does the outdoor sensor go on the IAQ or Aprilaire or both.

I believe that my Infinity has the variable speed as it starts out at a slow speed when it starts to heat and then ramps up to a higher speed.


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## beenthere (Oct 11, 2008)

Hook the wires that would normally go to the humidistat, to the IAQ.
Don't use the humidistat that comes with the Aprilaire humidifier.


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## hugginsg (Feb 1, 2009)

There are only two wires coming out of the Aprilaire 700 which normally connecto to the two H connections on the Aprilaire humistat. The Aprilaire humistat also has the R & C connections which would go to the R & C on the furnace. If I do not use the Aprilaire humistat then I only have the two wires from the humidifier itself.


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## beenthere (Oct 11, 2008)

Ooops, sorry about that.
Was doing too many things when I answered you earlier.

Jumper, From RH to HUM1 on the IAQ. Then connect the IAQ's HUM2 to the humidifier. Then connect the other wire from the humidifier to either the IAQ's C terminal, or the furnaces C terminal.
It doesn't matter which C terminal you use. They are the same common back at teh furnace transformer.


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## hvaclover (Oct 2, 2008)

beenthere said:


> Ooops, sorry about that.
> Was doing too many things when I answered you earlier.
> 
> .


Who were you banning when you made that "OOPPPS"?:laughing:


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## beenthere (Oct 11, 2008)

hvaclover said:


> Who were you banning when you made that "OOPPPS"?:laughing:


LOL... 

Some last minute changes to proposals.


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## jmcqueen (Feb 16, 2009)

*also, what about wiring AprilAire 5000 EAC to IAQ?*

much appreciate the post on the humidifier. i got it hooked up, but now i need to know how to hook up my aprilaire 5000 EAC to the IAQ. my aprilaire is the new-style one with the module base and module. it runs fine under wiring diagram #4 (direct to funace), but does not go through the IAQ's EIM. do i hook it up to VNT on IAQ? if so, which wires go to VNT?


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## fjpick (Feb 15, 2009)

*can anyone help with this*

just installed a honeywell humidifier he360b. Have read some post on line about shorting out motors when connecting wires from the control to the furnace. The furnace is a comfortmarker RPJ11. I understand w to w and cg to c and g to g but I want to know where exactly the fan timer board is. I believe it's on the bottom of the circuit board where I think the brown wires coming in are from the up stairs themostat.


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## beenthere (Oct 11, 2008)

EAC should be wired to the furnace EAC terminal, not the IAQ.


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## beenthere (Oct 11, 2008)

Furnace control board, is/has the timer built into it.


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## fjpick (Feb 15, 2009)

(EAC terminal) I've been looking for a picture of this all week-end. Couldn't find it. Is it at the bottom of the furnce where the wires from the upstairs thermostat tie into?


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## beenthere (Oct 11, 2008)

If yours has one.
It will be close to the fan speed tap terminals.


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## fjpick (Feb 15, 2009)

I have two brown wires coming into the furnce. One wire has a red and a white. They go to the board, white to C and red to Y.
The second wire has green, blue, white and red. Green wire goes to the G, Blue wire goes to the Y( same as the red from the 1st wire) white to W and red to R.
Is this where my W on the thermostat goes to W or the C ?
And where does the CW wire from the thermostat go?

Please answer this and I'll never bother you again.


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## jmcqueen (Feb 16, 2009)

jmcqueen said:


> much appreciate the post on the humidifier. i got it hooked up, but now i need to know how to hook up my aprilaire 5000 EAC to the IAQ. my aprilaire is the new-style one with the module base and module. it runs fine under wiring diagram #4 (direct to funace), but does not go through the IAQ's EIM. do i hook it up to VNT on IAQ? if so, which wires go to VNT?


yes, the IAQ's EIM (box mounted near the furnace). i currently have the aprilaire 5000 wired to the furnace board, but would like to wire it to the VNT terminals on the EIM. is this do-able and wouldn't this give me more functionality?


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## beenthere (Oct 11, 2008)

fjpick said:


> I have two brown wires coming into the furnce. One wire has a red and a white. They go to the board, white to C and red to Y.
> The second wire has green, blue, white and red. Green wire goes to the G, Blue wire goes to the Y( same as the red from the 1st wire) white to W and red to R.
> Is this where my W on the thermostat goes to W or the C ?
> And where does the CW wire from the thermostat go?
> ...


Don't know what you mean by CW wire.

From the IAQ's EIM to the furnace.

RH to R
W1 to W
Y1 to Y
C to C

From furnace to A/C
Y to Y
C to C


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## asnatlas (Feb 23, 2010)

I was doing some searching and came across this thread.

I have a Honeywell Equipment Interface Module (THM5421C) and I have installed an Aprilaire Humidifier (400A).
I have everything hooked up but I am having a problem with the "common" wire. I found the 24v "C" on the Honeywell Module.
I tried jumping "RH" to "H1" then "H2" back to the Hum controller, with the 24v connected, but nothing seemed to happen.
The Hum works when I connect both wires from the Hum controller to the "C" & "R" on the Honeywell Module, but I need it to come on only when the furnace is running.

Thanks for your time
Shawn


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## asnatlas (Feb 23, 2010)

I was looking at the IAQ manual and there are two wiring guides. One for power supply and one without.

I am using the 24v transformer that came with the 400A unit for continuous power on the Hum controller "R" & "C". I then hooked the "W/G" & "Cf" to the "H1" & "H2" terminals on the IAQ. But nothing.
As stated above. I also tried to jump "RH" to "H1" and then "H2" back to "Cf" with the "W/G" going to the "C" on the IAQ. Still nothing...

On my IAQ (THM5421C) I have a factory installed jumper between "R" "RC" & "RH".


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## beenthere (Oct 11, 2008)

I believe you need to tell the thermostat that it is controlling a humidifier.


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## asnatlas (Feb 23, 2010)

beenthere said:


> I believe you need to tell the thermostat that it is controlling a humidifier.


That is what I was thinking. The VisionPRO IAQ does show the humidity level and when I press "MORE" a few times it displays the Humidifier screen but there are no arrows to adjust any levels. I checked under the advanced functions and only found an option for Humidifier pad change reminder...


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## beenthere (Oct 11, 2008)

Manual for stat should tell you how to get into installer set up.
It will be in there somewhere.


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## asnatlas (Feb 23, 2010)

beenthere said:


> Manual for stat should tell you how to get into installer set up.
> It will be in there somewhere.


Ok, cool, I found it. I was looking in the Operating manual. I found the Installation Guide and it was under Setup function 0372. I set it from "E" (Auto Discover) to "1" Humidify with no frost protection. 

I then set the stat to 45% and connected both "H1" & "H2" and turned on the system and it did not work  I also tried to jump "RH" to "H1" and no go there as well


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## beenthere (Oct 11, 2008)

If your using separate transformers(the furnace has its own and the humidifier has its own). Quit jumping RH to H1, or you'll burn stuff up.

Did you set it to humidify only when there is a heat call, or anytime?

Read the install instructions. It goes over that.


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## asnatlas (Feb 23, 2010)

beenthere said:


> If your using separate transformers(the furnace has its own and the humidifier has its own). Quit jumping RH to H1, or you'll burn stuff up.
> 
> Did you set it to humidify only when there is a heat call, or anytime?
> 
> Read the install instructions. It goes over that.


Installer setup - 0374 is set to default "0" which is Humidify only while fan or heat is on.

Just to make sure I am understanding the wiring guide. Since the Aprilaire has its own 24v transformer I should just have to connect the "H1" & "H2" on the EIM to the "W/G" & "Cf" on the Hum Controller, correct ? If this is the case, it does not come on when the furnace kicks in  

I have checked the solenoid and it opens when supplied with 24v.


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## beenthere (Oct 11, 2008)

Wait.

W/G and CF are terminals on the Humidistat that comes with the 400. 
You don't connect that if your using the IAQ to control the humidifier.

1 wire from the humidifier's transformer goes to H1 of the IAQ, H2 of the IAQ goes to 1 wire of the HUMIDIFIER, and the other wire of the HUMIDIFIER goes to the other wire of the humidifier's transformer.


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## asnatlas (Feb 23, 2010)

beenthere said:


> Wait.
> 
> W/G and CF are terminals on the Humidistat that comes with the 400.
> You don't connect that if your using the IAQ to control the humidifier.
> ...


Correct the "W/G" & "Cf" terminals are on the HUM Controller. I want the Digital Controller that came with the 400A to control the Hum. 

If I am reading the diagram correctly that came with the 400A it shows that "R" & "C" should have continuous power from the provided 24v transformer. then "W/G" is 24v furnace acc terminal and the "Cf" is common.

Here is the diagram I am speaking of:









Here is the Hum Controller:









Here is the EIM:


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## beenthere (Oct 11, 2008)

Yes. that is correct wiring for the 400's humidistat.

So you want the humidifier to be controlled by the 400's humidistat. but the IAQ to control if it can run?


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## asnatlas (Feb 23, 2010)

beenthere said:


> 1 wire from the humidifier's transformer goes to H1 of the IAQ, H2 of the IAQ goes to 1 wire of the HUMIDIFIER, and the other wire of the HUMIDIFIER goes to the other wire of the humidifier's transformer.


One wire from the 24v transformer should go to "R" and the other to "H1" on the EIM. Then a third wire from "H2" to "C" on the Hum controller ??


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## asnatlas (Feb 23, 2010)

beenthere said:


> Yes. that is correct wiring for the 400's humidistat.
> 
> So you want the humidifier to be controlled by the 400's humidistat. but the IAQ to control if it can run?


Correct, I want the 400A to be controlled with the supplied digital controller but I only want the humidifier to run when furnace is running.


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## beenthere (Oct 11, 2008)

asnatlas said:


> One wire from the 24v transformer should go to "R" and the other to "H1" on the EIM. Then a third wire from "H2" to "C" on the Hum controller ??


No.

If you don't want teh IAQ to control humidity. Don't hook the 400's humidistat to it.

If you want to be able to humidify with just teh fan running. And not have the fan running 24/7.

Then just wire the 400's humidistat the way they show it, without it being connected to the IAQ in anyway.
And just tell the IAQ to control humidity. And to bring on the fan when it needs to humidify.

You can't really control your humidifier with the humidifiers humidistat and have it not be controlled by the IAQ if you wire it to the IAQ.

The IAQ is designed to REPLACE the humidifiers humidistat, not work with it.


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## beenthere (Oct 11, 2008)

asnatlas said:


> Correct, I want the 400A to be controlled with the supplied digital controller but I only want the humidifier to run when furnace is running.


If you wire it in with teh IAQ, then the IAQ will be controlling teh humidifier. Since the IAQ MUST call for humidity for the 400's humidistat to be able to turn on the humidoifier.


Your making it harder then what it is. The IAQ can do all that the 400's humidistat can do.


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## asnatlas (Feb 23, 2010)

beenthere said:


> If you wire it in with teh IAQ, then the IAQ will be controlling teh humidifier. Since the IAQ MUST call for humidity for the 400's humidistat to be able to turn on the humidoifier.
> 
> 
> Your making it harder then what it is. The IAQ can do all that the 400's humidistat can do.


LOL I am very sorry about all this. This is the first HVAC DIY  The IAQ controlling the Hum is fine. I am just having a problem understanding how to link them together with the "W/G" and "Cf" terminals on the Hum controller.


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## asnatlas (Feb 23, 2010)

I also want to THANK YOU VERY MUCH for all your time in replying...


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## beenthere (Oct 11, 2008)

asnatlas said:


> LOL I am very sorry about all this. This is the first HVAC DIY  The IAQ controlling the Hum is fine. I am just having a problem understanding how to link them together with the "W/G" and "Cf" terminals on the Hum controller.



There is no reason to have the 400's humidistat in the circuit.

The IAQ can control the humidifier. 

And you are welcome.


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## asnatlas (Feb 23, 2010)

beenthere said:


> There is no reason to have the 400's humidistat in the circuit.
> 
> The IAQ can control the humidifier.
> 
> And you are welcome.


So I can just move the outdoor temp sensor over to the EIM along with the two wires from the solenoid valve and be done ??

I see Out 1 and 2 terminals on the EIM for the temp sensor. 

Where would I hook up the two wires from the solenoid valve ? "H1"& "H2" ?? Or do I need to connect one to "C" and jump "RH" to "H1" and then the 2nd wire from the solenoid valve going to "H2"


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## beenthere (Oct 11, 2008)

If its the same type of temp sensor, you can use it with the IAQ.

One wire from new transformer to H1 of EIM, H2 of EIM to one wire of humidifier. Other wire of humidifier to C(common) of new transformer.


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## asnatlas (Feb 23, 2010)

Nice, I got it working off the IAQ  Thanks again for your help...


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## beenthere (Oct 11, 2008)

Your welcome.


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