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Ask Airheatman Your Own Question
Airheatman, HVAC Technician
Category: HVAC
Satisfied Customers: 7517
Experience:  Furnace, A/C and heat pump specialist.
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How to install Nest with preferred 90+? 20 min, it would be

Customer Question

How to install Nest with Bryant preferred 90+?
JA: I'll do all I can to help. How long have you been dealing with this?
Customer: 20 min
JA: Do you plan on doing the work yourself?
Customer: it would be best im poor
JA: Anything else we should know to help you best?
Customer: It currently is using a T6-PRH-A thermostat
JA: Just to clarify, do you think this is a larger HVAC problem, or something specific to the thermostat?
Customer: just trying to switch it with a nest
Submitted: 1 month ago.
Category: HVAC
Expert:  Airheatman replied 1 month ago.

Give me a few moments to compare the thermostats. Can you also provide model on indoor and outdoor units and tell me what wires were connected to the old thermostat?

Customer: replied 1 month ago.
the old thermostat in the living room has V+ and V-. It is connected a control module that has RC, W/W1, G, Y/Y2, C, Y1/W2, DAT, SRTN, & HUM. The DAT and SRTN lines go to the unit outside.
Expert:  Airheatman replied 1 month ago.

OK the Tr- thermostat is using the control module .You may or may not be able to use the Nest .

As a minimum it will require running additional wires between thermostat and air handler.

Please provide model on Module and also on your units so I can see if it is possible to use the NEST.

Customer: replied 1 month ago.
Bryant Preferred 90+ HVAC system with the T6-PRH-A thermostat. The control module may be A07219, but it is the one that goes with the thermostat.
Customer: replied 1 month ago.
Additional wires will not be a problem
Expert:  Airheatman replied 1 month ago.

OK the furnace will have a model inside burner compartment.Something like 926T100V or similar.

Can you get that for me? And tell me exactly what wires are connected to furnace board from the module.

Customer: replied 1 month ago.
We see all the wires at the control board on the main unit, but can not figure the DAT & SRTN lines that go to the outside unit
Customer: replied 1 month ago.
Yep.. Standby please
Customer: replied 1 month ago.
maybe 334942-101 Rev. A.. from this board, Y1 goes to W2/Y1 on the control module, green goes form G to G, Blue is Com to Com, White goes from W1 to W1, yellow goes Y/Y2 to Y/Y2. The control module is #TS-PRH01-A.
Customer: replied 1 month ago.
The control module has the DAT and SRTN connections to the outside unit.
Customer: replied 1 month ago.
the interior has a sticker with the model #CNPVP4821ATAABAA, if that helps
Expert:  Airheatman replied 1 month ago.


Now here is what we will do.We will completely remove the old thermostat and the module .

Then we will run new wires to thermostat from furnace. (I will tell you where to connect them)

That should be OAT and SRTN.

Those 2 wires will be unused and taped off. They go to an outdoor temperature sensor in outdoor unit to provide the thermostat with current outdoor temp. They are not needed as NEST will use WIFI for this information.

Customer: replied 1 month ago.
Excellent!! What is the pin out? and can we use 22 gauge stranded wire?
Customer: replied 1 month ago.
new cable is run
Expert:  Airheatman replied 1 month ago.

I a typing wiring now

Expert:  Airheatman replied 1 month ago.

Just about finished. One quick question, Can you tell me how many wires run from furnace to outdoor and what they connect to in outdoor?

Customer: replied 1 month ago.
Stand by, ill try
Expert:  Airheatman replied 1 month ago.

Take your time

Customer: replied 1 month ago.
Colors going outside- red is on C, white Y1/W2, yellow Y/Y2, OAT is black, SRTN is brown. Going outside to see where they land..
Expert:  Airheatman replied 1 month ago.

THanks for that information.Be done shortly with typing wring

Expert:  Airheatman replied 1 month ago.

Wire as follows


RH-----------------------------------R (THis is 24 v power)

Y1----------------------------------- Y1----------------------Y1 (This signals contactors in outdoor unit first stage)

Y2------------------------------------Y2---------------------Y2 (This controls outdoor unit second stage)

W1---------------------------------W1) (This controls heat)

C--------------------------------------C-----------------------C (This is 24 v common)

G--------------------------------------G (This controls indoor blower)

Black and Brown can be taped off in outdoor unit.

Customer: replied 1 month ago.
Thank you
Customer: replied 1 month ago.
Well done.
Expert:  Airheatman replied 1 month ago.

If you can wire as listed and check everything out we should be good. Please wait to rate until we make sure all is good to go.

If you have further questions, please let me know.

Thanks for letting me work with you.If my answer has been polite, professional,and thorough, please click one of the ratings before you go. If you still need help let me know!.Expert is not paid for assisting you until you rate answer.Feel free to follow up for 30 days at no additional cost. Bonus always appreciated if you feel justified.

To rate answer, please select one of the stars on the page.

Expert:  Airheatman replied 1 month ago.

Were you able to test yet?

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