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New thermostat (2GIG CT100) in place of two old boiler and A/C thermostats

New thermostat (2GIG CT100) in place of two old boiler and A/C thermostats


  #1  
Old 03-31-14, 05:37 AM
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New thermostat (2GIG CT100) in place of two old boiler and A/C thermostats

I need help hooking up a new 2GIG CT100 thermostat to a boiler (Burnham 204HNSL-BEI2) and an A/C unit (outside compressor and air handling unit in the attic - Compressor is a Carrier model A30X....I think....and I'm unsure of the make/model the air handling unit). Both the boiler and A/C units had old dial thermostats hooked to them. The A/C unit had 4 wires hooked to the old thermostat (White, Green, Red, and Yellow - there's a blue wire which was not hooked up). The Boiler has 2 wires (Red and White).

How do I hook the available wires to my 2GIG CT100 so one thermostat can control both the boiler and A/C units?

See linked picture below for exposed wires which were hooked to a dial thermostat on the left, and the existing dial thermostat for the boiler at right.

imgur: the simple image sharer
 
  #2  
Old 03-31-14, 10:04 AM
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I think A30x is a bad number.
What kind of heat is the left stat controlling at this time?
Are you wanting to use the boiler as stage 2 heat?
 
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Old 04-01-14, 07:13 AM
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Thanks for the response Houston204. You're right, the model number I had was not correct. The model of my Carrier unit is 38TXA030320. This is the outside compressor unit. The air handler unit is in the attic. I can get the model number of that as well, if you need it.

The thermostat on the left in the picture ONLY controls the air conditioning. There's no heating currently on that stat. The right thermostat ONLY controls the boiler currently. My goal is to have the 2GIG CT100 control both the air conditioner and the boiler from a single stat.

Let me know if you have any additional questions or if I can get more information or pictures for you to help solve my problem.
 
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Old 04-01-14, 06:35 PM
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What was the white wire connected to on the left stat?
I would also check the white wire at the air handler.

A common color code is...
R = red = 24 volt power
G = green = fan
Y = yellow = cool
W = white = heat
 
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Old 04-02-14, 02:42 PM
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The left stat had 4 terminals with the wires connected, and those terminals are labeled W, G, R, Y with White, Green, Red, and Yellow wires connected at the terminals. I'll also put a multimeter on the wires to see if I can identify one of them as the "C" wire.

I'll try to get up into the attic tonight or tomorrow night to see if I can trace the stat wires and to get the air handler model number for you.

Thanks again for your help!
 
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Old 04-02-14, 02:58 PM
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It is unlikely that any of those four wires is C. You may be able to use white for C by moving it at the indoor unit if is not in use for an electric heat strip. A picture of the wire connections at the air handler would be of assistance. It may be necessary to fan out the connections to clearly see what went where.
 
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Old 04-02-14, 02:59 PM
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OK, good to know. Thanks. I'll let you know what I find when I make it into the attic to further investigate.
 
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Old 04-02-14, 04:29 PM
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The panel that does not have copper pipes running it through it probably has something like this in a corner. "Fanning out" the wire connections might make it easier to see the connections.



These are common wire connection (though Carrier will have a gray wire from the air handler connected to stat G).
 
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Old 05-19-14, 03:29 PM
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I was finally able to get into my attic to take a look at the air handling unit. I was able to trace the thermostat wire to where it entered the unit, but couldn't find the panel where I could see the exposed wires and wire nuts making connections. I did find the sticker on the unit with the model number (Carrier FK4CNF002 - see attached picture). Do you, by chance, know which area of the unit has the panel where the wire connections are made so I can verify where the red, green, white, and yellow wires from my thermostat are connected to on the unit?
 
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Old 05-19-14, 07:10 PM
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See page 14 for view of terminal strip. There is a C terminal available. This terminal strip can be found behind the door on the same side of the unit where the refrigerant lines enter but at the opposite end.

Carrier download.asp3Ddocs 2Fcm116.pdf
 
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Old 05-22-14, 04:09 PM
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I found the board (see attached picture), and it looks like red, yellow and green are the only wires used from the handling unit to my thermostat. I see a 'C' terminal, but it looks like that is being used for communication to the compressor (it looks like a red and white wire are going to the compressor outside).

Can I connect a wire to the 'C' terminal on the board and then to the 'C' terminal on my thermostat to get power to the 'stat?

While looking at the board I also found that my 3 amp fuse was blown. So I am going to replace that as well.

Thanks for all your help. You have been great!
 
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Old 05-22-14, 06:29 PM
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Can I connect a wire to the 'C' terminal on the board and then to the 'C' terminal on my thermostat to get power to the 'stat?
Absolutely.

Best to turn power off to air handler before making wiring changes to prevent protection fuse from blowing.
 
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Old 05-26-14, 08:41 AM
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PJMax,
Thanks for all your help. I was able to connect my 2Gig CT100 thermostat to both my air handler/air conditioning unit as well as my boiler while also powering my thermostat with the newly connected "C" wire at the air handler. Things are working perfectly now all thanks to you! Many thanks for your prompt, accurate, and detailed responses to my questions.
-Irestone
 
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Old 05-26-14, 09:31 AM
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Awesome..... good job You're welcome.
 
 

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