AS Heat Pump thermostat wiring
#1
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AS Heat Pump thermostat wiring
I am a DIY installing a new American Standard 3T heat pump/air handler model GAF2A0A36S. I am currently trying to hook up the low voltage control lines for the thermostat and heat pump. Per the “Air Handler Hook-up Diagram Heat Pump” there should be 7 pigtails for this attachment. Per the “Wiring Diagram for GAF2A0A36S Air Handlers”, there should be only 4 pigtails. My machine has only 4 wires WH, GR, RD & BL as shown on the wiring diagram.
Any ideas on how to wire this bad boy?
I appreciate any help available/provided.

Any ideas on how to wire this bad boy?
I appreciate any help available/provided.


#2
Welcome to the forums.
I was finding conflicting information. My partner, Houston, will probably have a better idea of your wiring.
I was finding conflicting information. My partner, Houston, will probably have a better idea of your wiring.
#3
If you do not have YLo, O or Y at the air handler these wires would bypass the air handler and go from the stat to the heat pump. (I doubt that you have Y1 and Y2 in use with that air handler)
What is the model number of the heat pump and the stat?
What is the model number of the heat pump and the stat?
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The compressor is an American Standard 3.0 Ton 13 SEER Heat Pump Condenser model 4TWB3036C10. I haven't unboxed it yet but can pull the manuals to see if there is any additional info or diagrams should you need it.
You are saying (at least at this moment) to connect:
FROM THERM -- AT HP
Orange -- Orange
Yellow -- Yellow???
and ignore Orange at AH since there is none.
Incidentally I will have a qualified AC guy make braze the copper and charge/test unit. I am pretty good but I do know when to call in the pros.
Thanks for the quick turn around on assistance. I am always impressed by how helpful the "community" can be in the technical world.
You are saying (at least at this moment) to connect:
FROM THERM -- AT HP
Orange -- Orange
Yellow -- Yellow???
and ignore Orange at AH since there is none.
Incidentally I will have a qualified AC guy make braze the copper and charge/test unit. I am pretty good but I do know when to call in the pros.
Thanks for the quick turn around on assistance. I am always impressed by how helpful the "community" can be in the technical world.
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Great job Houston204!
I went over to the house and pulled the H-P manual. Sure enough they had a different diagram in that manual. It seems there are (at least) two different models of the GAF2 Air Handlers, and the installation instructions that came with mine failed to mention that it was not for the version that they had sent ...of course!
As you can see in the attached diagram your solution was dead on and if I had just been wise enough to pull the H-P manual I would have found the solution myself. Hopefully this post with the 3 diagrams will save someone else from struggling with the same issue.
Again thanks for your great and very quick response, over a weekend none the less. It is much appreciated.
I went over to the house and pulled the H-P manual. Sure enough they had a different diagram in that manual. It seems there are (at least) two different models of the GAF2 Air Handlers, and the installation instructions that came with mine failed to mention that it was not for the version that they had sent ...of course!
As you can see in the attached diagram your solution was dead on and if I had just been wise enough to pull the H-P manual I would have found the solution myself. Hopefully this post with the 3 diagrams will save someone else from struggling with the same issue.
Again thanks for your great and very quick response, over a weekend none the less. It is much appreciated.
