Any(home) heating and cooling experts? Thermostat install problem.

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Johnny Mac

Johnny Mac

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So I have changed probably ten thermostats in houses in my life, and I am now deferring to hopefully someone why can help. All my experience has been with 3 wire or 4 thermostats.....this thing has 5. Pics to follow....I pulled off an old round style from the 60's. And nothing was lettered inside....so assuming the new one was just color coded...tossed it asside.
Well...I have found a random combo where the heat wil work. But no AC.
Unit is a gas furnace, with external AC unit. The orange wire was pushed back in the plaster. Not in use.
Rh and rc were originally jumped together. I removed it trying to follow the useless install diagram. So wtf do I have crossed. I feel like an idiot. Lol
 
Forgot to mention im in ne ohio. A c service rep told me I was sol due to different areas being coded diff. Dunno if thats true.
 
The R and RC may need to be jumpered, I cannot tell

"Standard" color coding starts out

RED is 24V supply

WHITE is heat, or stage 1 heat

GREEN is blower

YELLOW is AC

You should be able to tell "what you have" by removing the wires and jumpering them

Jumper RED to these, one at a time..........

to GREEN should bring on blower

to YELLOW should bring on outdoor unit, most units, the stat brings on both green and yellow to the red to accomplish cooling. Some units have a built in time delay in the AC unit, so you may have to wait up to five minutes for the OD unit to come on.

RED to WHITE is heat. Depending on what you have for heat, this could take a minute, as well. Burner should fire, a minute or so, and then blower should come on.

That stat.........without looking at destructions........may be multi-purpose. The extra stuff is for a heat pump. W2 is second stage heat, O or B is for reversing valve in a heat pump and Y2 would be second stage cooling
 
you might want to level so temp will be right, i think your rc and rb should have 1 wire and a jumper and the other wire to w2 or o. turn power off while doing any wire changes so you dont fry the transformer
 
moparshaker said:
you might want to level so temp will be right, i think your rc and rb should have 1 wire and a jumper and the other wire to w2 or o. turn power off while doing any wire changes so you dont fry the transformer
Click to expand...

Not in anything I've ever worked on. W2 is second stage heat, and O is normally for a reversing valve on a heat pump

OP........can you post a link to the model of this thing, and better yet to the destructions?
 
Only 5 wire diagram on the instructions? Unless.its a 4 since the Orange was just left off the old one?
What else can I post to help u guys help me...
Hunter 44143
 
Am I blind or are there two green wires there?

Also O is for heat pumps and would have an orange wire but that's irrelevant.

67dart is explained the colors and functions well.
 
As u can see. It doesn't coincide with my colors...
I have coming out of the wall..
Red
Pale blue
Green
White

And an orange that wasn't used on the last thermostat
 
I don't see a yellow wire in your picture which may explain why the ac isn't working. Maybe my eyes are failing me though.
 
Dont have a yellow...but everything worked before I pulled the brass unit...
Green to red activates fan
 
johnnymac2k6 said:
As u can see. It doesn't coincide with my colors...
I have coming out of the wall..
Red
Pale blue
Green
White

And an orange that wasn't used on the last thermostat
Click to expand...

The pale blue could be a common and is easy to test with a voltmeter. Just test the red and blue and see if you get anything. Worst case scenario just go outside and look at the 24 volt wires going to the unit. If there isn't a yellow one in there then I would call ghost busters. Unless they used light blue instead of yellow. If that's the case then someone needs smacked for the head ache
 
doogievlg said:
The pale blue could be a common and is easy to test with a voltmeter. Just test the red and blue and see if you get anything. Worst case scenario just go outside and look at the 24 volt wires going to the unit. If there isn't a yellow one in there then I would call ghost busters. Unless they used light blue instead of yellow. If that's the case then someone needs smacked for the head ache
Click to expand...
And blue...is the a.c. unit lol it kicked on. When to red
 
doogievlg said:
The pale blue could be a common and is easy to test with a voltmeter. Just test the red and blue and see if you get anything. Worst case scenario just go outside and look at the 24 volt wires going to the unit. If there isn't a yellow one in there then I would call ghost busters. Unless they used light blue instead of yellow. If that's the case then someone needs smacked for the head ache
Click to expand...

If you measure from any of the function wires to red you should measure 24V. Measuring voltage from Red to blue does not prove anything, IE if the blue is to replace the yellow, it will still show 24V because of the load of the "yellow."

I would pull the power on the OD unit and the furnace, and check resistance between blue and red. Quite low resistance would show that the blue is indeed a common. You will be measuring the resistance of the 24V transformer

I cannot imagine, that with heating and AC, that there is a common there. SOMETHING has to activate the AC

EDIT........I was posting as you were. so there you are.........blue replaces yellow
 
So...red to rh
Blue to y
Green to g
White to w
Leave orange alone? See what happens?
 
RE your stat diagram......I would jumper Rc and Rh, and hook the blue wire to the Y terminal.
 
Interesting thread. Carry on, I'll try to keep up. I did a Manual J to double check the hvac needs on my 100 year old house. Can I hang with you guys? lol Carry on!
 
67Dart273 said:
RE your stat diagram......I would jumper Rc and Rh, and hook the blue wire to the Y terminal.
Click to expand...

X2!

You know when the guy wired that and used a blue wire he was thinking to himself how funny it would be in the future. Although if it's a really old system then I'm not sure if they still had the same color code. Anyways enjoy your AC! Not that you will need it for a while up there.
 
67Dart273 said:
RE your stat diagram......I would jumper Rc and Rh, and hook the blue wire to the Y terminal.
Click to expand...

Bingo.!!!!!!! Took the jumper, but it worked. You guys are the best!
 
doogievlg said:
X2!

You know when the guy wired that and used a blue wire he was thinking to himself how funny it would be in the future. Although if it's a really old system then I'm not sure if they still had the same color code. Anyways enjoy your AC! Not that you will need it for a while up there.
Click to expand...

Its actually been 70. The last few days! We were hot today lol. As long as the heat kicks on on in a min we r golden

And ya..must be the same guy that reverse wired all the Gcfi outlets lol. I love old houses
 
In my service years there was still a lot of older stuff I serviced and repaired. "Be ready for anything" including a spliced stat wire that CHANGED COLORS from one end to the other.

I should have wrote a book, LOL. I'm starting to forget a few things.
 
67Dart273 said:
In my service years there was still a lot of older stuff I serviced and repaired. "Be ready for anything" including a spliced stat wire that CHANGED COLORS from one end to the other.

I should have wrote a book, LOL. I'm starting to forget a few things.
Click to expand...

I do service work at apartment complexes. Luckily the property I spend the majority of my time at is electric heat and the buildings are only 30 years old. Went in to a vacant that the maintenance guy said needed rewired. No sequencer, no relay, no transformer, no thermostat. Had to rewire the hole things pretty much from scratch. The other properties have aqua therm, and gas furnaces, and heat pumps. I'll take the AC season over Heat anyday.
 
doogievlg said:
I do service work at apartment complexes. Luckily the property I spend the majority of my time at is electric heat and the buildings are only 30 years old. Went in to a vacant that the maintenance guy said needed rewired. No sequencer, no relay, no transformer, no thermostat. Had to rewire the hole things pretty much from scratch. The other properties have aqua therm, and gas furnaces, and heat pumps. I'll take the AC season over Heat anyday.
Click to expand...

What?? did someone strip all the controls out of the furnace?

I've reworked a few. "The one" (actually two) I wish I'd walked away from and I cannot remember the name of the damn things

These sere one of the first electric furnaces with an electronic T stat. Problem is, the whole SYSTEM was weird. Instead of the conventional "strung" heat elements, these used an enclosed element, like a pi-rod. The controls and T stat was proprietary, and was DC, not AC. I don't remember if it was 12 or 24. Anyhow, even back in the 80's you could not get parts for them that we knew of, at least reliably.

So I tore one apart and proceded to re-wire it with conventional 24V AC and sequencers. As I remember, there was some problem that took me a long time to work out. I remember I never wanted to see another!!
 
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