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Discussion Starter · #1 ·
I am installing a new Honeywell thermostat with our variable speed american standard furnace. I am missing the c wire as it only has 4 wires now. I ordered and will pull a new 8 wire cable as access is pretty easy. My question is how far should I go....

If I pull the new wire and connect how it is....it appears the white wire is ran to w2 AND w1 on the furnace. I believe this means it is set to timer mode and runs on low for 10 minutes then switches to high heat mode.

I can run it how it is, add the c wire and leave the new thermostat in the default settings it comes as correct?

OR

Should I run a separate wire for w1 and w2? This would change the thermostat to call for stage 2 I believe. I am not sure what is all involved if I did that. I am thinking change the thermostat to reflect 2 stage? I am thinking I also have to change something on the furnace......Is all of that worth it or just run it like it is adding the C wire?
 

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I would use the W2 wire BUT there should be a dip switch/switch on your circuit board which you need to change to tell it to use a 2 stage thermostat.

That info should be in the install manual that came with it.

By default it is set to use the timer. You will be more comfortable using the 2 stage and W2.

You may also have to set a option in the thermostat program for 2 stage use.
 

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I believe AS/trane uses a jumper between w1 and w2 when a single stage stat is used - when both are initially energized at the same time it delays second stage by 10 minutes.

for a 2-stage stat, you remove the jumper and connect w2.

this could be wrong so check the manual.

thermostat controlling the staging is much better than timer.
 

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Discussion Starter · #5 ·
Thank you everyone. It is a model AUH2B080A9V3VBA. I am trying to find the manual now....

On the thermostat side would I just change to a 2 stage heat 1 stage air then?
 

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Discussion Starter · #7 ·
Is there anywhere I can find the manual online for these? I have the documentation they gave but no manual/installer guide. Trying to find out if there is a switch I need to change or just install both wires as indicated potentially.
 

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i generally just search.

the t-stat setup may have changed so check the manual it came with. it may ask you to set efficiency instead of cycle rate -> high efficiency furnace setting = 3 cph.
 

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I found a manual for it and it appears there are 2 dip switches.

One to adjust the fan off delay time when the burner shuts off and another for adjusting the time between stages when using a 1 stage thermostat.

The wiring diagram just shows a jumper between W1 and W2.

Try remove the jumper and hookup W1 and W2 and same at the thermostat/tstat.

Then fire up the furnace and increase the temp 1 deg F and see if it starts on low fire.

Then increase it 1 deg F and within a minute it should go to high fire and you will hear it get louder and the blower blowing harder and more air from the vents.

If it does not do that then try increase it 2 deg F. It may be looking for 1 to 1.5 deg F more. usually 1 deg F.

I did not find the actual install manual but I don't think you can damage anything this way. It may just stay on low fire forever w/o the jumper and a dip switch change if it even has one to change.
 

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No DIP switch to set. Just remove jumper and connect W1 and W2 separately. Then set up thermostat for 2 stage heat and one stage cool as you said.
 

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Discussion Starter · #15 · (Edited)
Wanted to post an update. Ran the wire which was a little harder than I thought. Old wire was stapled in multiple sections so I ended up fishing a new 8 wire down a different path.

Then connected 6 wires adding the c and separate w wires. Configured the thermostat for 2 stage heat and high efficiency. Tested both heat and cool and everything is working great.

Wanted to post a thank you to everyone that posted with the advice. I think we will be happier with the true two stage and everyone's advice gave me the confidence to get it done myself.

Thanks.
 
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