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Installed Nest and Lennox Furnace Fan Stays Always On - AprilAire 700

Installed Nest and Lennox Furnace Fan Stays Always On - AprilAire 700


  #1  
Old 11-16-12, 06:45 AM
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Installed Nest and Lennox Furnace Fan Stays Always On - AprilAire 700

Hi guys. I replaced my simple old Honeywell thermostat with a 2nd generation Nest. Everything was working fine before the Nest. Picture of the Honeywell thermostat below:



The first time I installed the Nest my furnace would not work. Later I found that I accidentally had cross-wired the blue and red wires. I am only saying that in case you think that broke something or it's related to my problem (the fan stays on constantly). The picture below shows the wires after I "fixed them" so I think they are correctly connected. Again, the first time, I had the Red wire on C and the Blue on Rh.




Although I had the power switch from the main board turned off (AC was off and furnace was off), when I switched the red and blue wires (to the correct position), I heard the fan of the furnace turn on immediately. I dont understand that, should i have also turned it off from the on/off switch by the furnace which looks like the type we use for turning on/off the lights? Regardless....

My problem is that the fan stays on constantly.

My furnace is a Lennox c33-60d-2f-6 and I also had a professional isntall an AprilAire 700A (a year ago, before the Nest which was put on yesterday). Btw, I always wondered if that AprilAire is pushing enough humidity because I have it set to 7 (highest) and its panel never shows more than 43% to 47% humidity. I never saw my windows fog up. Not saying I need them like that, I know it's not good, but at setting 7 shouldnt they? My house is 3600 sq/ft large, three levels, the 700A should be able to make that house feel very humid at 7 I figure.

The professional told me he used a wire that was already going outside to the AC, to connect the Aprilaire's outside temp sensor (I was not there when he did it so I cannot attest). However I have taken pics of everything I can see for you guys to give me advice. I appreciate any help!

Here are some photos. This is the picture underneath the AprilAire 700





I am not sure what this is but seems to might be connected to the furnace and maybe to the humidifier? Not sure.



The humidifier's panel:




More on the connections of the humidifier

 
  #2  
Old 11-16-12, 06:12 PM
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Ok, we'll look at the Nest stat/furnace fan for now..

Make sure the stat fan "ON" isn't on.

if it's set to "AUTO", then try to remove the G wire and see if the fan stops.. If it stops, then it's the stat issues..

if the fan stays on, then go to the furnace, and remove the G wire there. If the fan does then stop, then there's a short in the wire somewhere.. If then fan dont stop, then it's the furnace.
 
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Old 11-19-12, 03:48 PM
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Thanks for trying to help.

I talked to Nest and they said that it was their base which was sorted. Sent me a new one, I installed it and it works fine now.

Now my question is, should I have the AprilAire humidifier connected directly to the Nest via the STAR connection? If yes, how can I do that myself?

On the wall, where all the wires come in, there are three other colored wires that are not used currently. Folded aside. They are brown, orange and black.
 
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Old 11-19-12, 04:02 PM
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YOu can wire it to it.. What do you hve for control on it now? Does it have an outdoor sensor on it?
 
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Old 11-26-12, 02:19 PM
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Hi, sorry for the delay. Thanksgiving.

Yes, it does have an outdoor sensor on it.

I am not sure what you mean by "What do you hve for control on it now?" A professional installed it. Some of the pics I posted show what he did. Let me know if you need more. Thanks for trying to help.
 
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Old 11-26-12, 02:28 PM
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Do you have a duct mounted humidifier control wired to the humidifier at this time?

Model?
 
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Old 11-26-12, 02:58 PM
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With the current humidistat you have, it will adjust the humidity to the corect level based on the outdoor temps.

I don't see anything on Nest saying that they do this thing. so you will have to adjust the levels as the temps changes outside.
 
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Old 12-05-12, 04:12 PM
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Yes I do. It's showing in the pics below. It's the one with the 42% showing. It's placed on my return main duct (meaning the portion of the furnace before the air filter.).
 
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Old 12-05-12, 04:15 PM
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Yes true. THe problem is this Aprilair unit will not allow more than 45% humidity IN THE DUCT. Which translates into 39% at best on the first floor where, per the Nest thermostat. I believe it. Plus it's lower upstairs in teh bedrooms I am guessing. It just does not feel humid enough and I have it cranked up to the top. I would say another 5% would be good to have. On the other hand, had I connected it to Nest I am thinking, I may lose the ability to include in the calculation the outside temp? Not sure. And confused.
 
 

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