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mooreci
join:2014-07-04

mooreci

Member

[HVAC] New Thermostat Installation

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Hi second pic is borrowed. Please ignore wires coming out of wall.
There are actually 2 sets of wires.
One set has a red and white wire.
Red1 and White1
The other set has four.
Red2, White2, Green and Yellow

The connections in first pic are as follows.
Red1 is connected to C
White1 and Yellow are connected to Y
Green is connected to GC
Nothing is connected to SH
Red2 is connected to R
White2 is connected to W

I tried Red1 to C, Yellow to Y, Green to G, Red2 to R, and White2 to W.

Everything worked except for the outdoor AC unit.
My T-stat displayed "looking for equipment"

Any help greatly appreciated.


Tex
Dave's not here
Premium Member
join:2012-10-20

Tex

Premium Member

Do you have a R and RC jumped at the thermostat? A thermostat model would be helpful.
mooreci
join:2014-07-04

mooreci

Member

Yes. It is the Honeywell RTH9580.

pende_tim
Premium Member
join:2004-01-04
Selbyville, DE

3 edits

pende_tim

Premium Member

Can you verify that the Red1 and White1 are the power for the thermostat?

Also, according to the manual, there is a message that comes up on power up "waiting for equipment" This is the compressor lockout timer. Usually 5 minutes. I realize this is not the message you indicated but sometimes we get aggravated and codes get garbled. LOL

Did you happen to take a picture of the old thermostat's connections? I see there is a picture of the connections at the unit.

Just in case here is a link to the manual: »pdf.lowes.com/useandcare ··· _use.pdf

The Y terminal usually controls the cooling contractor directly and should not have 2 wires on it in the thermostat. There can be 2 wires on the Y in the air handler as that would be the splice point for the run between the thermostat and the outside unit.

Having said that, please verify that the red1/white1 wire in the thermostat is the same red1/white1 wire in the air handler.

Is this a packaged unit with the air handler blower and compressor all in one package? Reason for that question is I don't see any wires to the outdoor unit if the red1/white1 are really going to the thermostat. Typically the outdoor compressor control is between the C and Y. That is why I am asking you verify the R1 and W1 at the thermostat are the same as the red and white on the airhandler. It is possible that the wires o the air handler go outside rather than to the thermostat.

If by chance the red1/white1 at the thermostat are being powered from a separate transformer, connect the white to C and the Red to Rh ( or Rc since they are jumpered ). on the thermostat and it should work.

Tex
Dave's not here
Premium Member
join:2012-10-20

Tex to mooreci

Premium Member

to mooreci
Looking at your first photo and the Red1 and White1, are they from two separate cables? Also, do you have a C wiring going back to the thermostat? According to the manual, that thermostat requires 24V to operate. Can you post a photo of the thermostat wire connections?

pende_tim
Premium Member
join:2004-01-04
Selbyville, DE

1 edit

pende_tim

Premium Member

I would suspect they are two cables as would be confusing as heck to have two white and two red (without tracers) under the same jacket?

It would not surprise me that the red1 and white1 go to the outside unit and the thermostat has a different cable to a separate transformer for power. If this is the case he needs to move the power wire from the y terminal to either Rc or Rh terminal as they are jumpered .

Tex
Dave's not here
Premium Member
join:2012-10-20

Tex

Premium Member

What I meant was there should be only one cable going to the condensing unit from the C & Y terminals at the furnace. It looks like C (Red) is in one cable and Y (White) is in another cable. Why two cables? Maybe it's because the photo is out of focus in that area, but it sure looks like two cables to me.
mooreci
join:2014-07-04

1 edit

mooreci

Member

Thanks for the responses.

You are correct sir about the message being "waiting for equipment". Aggravated and garbled are also correct. LOL

I didn't take pictures before hand because the thermostat that I am replacing didn't keep a set temperature. It would either heat above or cool below the temperature selected.

I assumed that it was wired incorrectly. I knew that I would have to find out which wire is for what by checking the panel.

There are two seperate cables coming out of wall.

One with Red and White
One With Red, White, Yellow, and Green.

White1 and Yellow were connected to a Humidistat.
Both reds, Green and White2 were connected to the thermostat.

I'm really not sure if Red1 and White1 are the same wires. That will be first once I get at it again. I'll also post a picture of thermostat wiring once I get home also.

The thermostat did power on with Red1 connected to C. I'm just not sure where R1 is coming from.
mooreci

1 edit

mooreci

Member

Click for full size
C
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D
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E
Click for full size
F
Red1 and White1 in first pic are not the same two coming out of wall.
Their sleeves are totally different. Too dark to notice last night. They must be going to the AC unit like suggested. Thanks

I connected everything like before just to cool house down.
The red wire on right (pic C) is the wire installed into Y (pic E).
The other White wire and the yellow wire are connected to Humidistat. pic (D)

The blue wire was cut too short to use. If I run another set of wires and leave the Humidistat wires be. Where do I connect the C wire? (pic A)

Thanks again

pende_tim
Premium Member
join:2004-01-04
Selbyville, DE

1 edit

pende_tim

Premium Member

OK so the R1 and W1 in Picture A go to the outside unit correct? You need to follow these wires and verify where they go.

You also need to find out the source of the Red and White wires coming out of the wall in their own sheath.

I honestly do not have a clue how the humidifier is working. The Yellow wire on the thermostat controls the compressor on the outdoor unit. Being summer you do not need it so that can slide for a while.

If you want to run new wires get a 6 conductor cable: and connect Like colors to like colors on both. Y to Y between the air blower and the thermostat, R to R , G to G, W to W, Y to Y and use Black between the C on the air unit and the thermostat C.
The function of these wires is as follows: Red=power, G is fan, W is heat and Y is AC compressor. C is the common power wire Reference: »home.howstuffworks.com/h ··· tat3.htm This example has separate Rc and Rh wires. In yours the Rc and Rh are jumpered.

For now leave the odd Red and Yellow wires associated with the humidifier alone.

This will give you basic air conditioning and heat.

More information is needed to sort out the humidifier connection and operation.
psiu
join:2004-01-20
Farmington, MI

psiu to mooreci

Member

to mooreci
One note, pic E, you should try to trim back the bare wire to have just enough to stick into the terminal blocks. Otherwise you run the risk of them shorting together.

Past that, good luck. Glad my thermostat replacement went well when we moved into our new house this spring :P

(I mean, it's about the *only* thing, but hey)