Heat Pump thermostat wiring

[seDIYgal]

I want to do a DIY replacement of a 9 yr old thermostat that is not very accurate.

I purchased the Honeywell RTH7500D 7-day programmable thermostat as the replacement. The package says it is heat pump compatible. I did a replacement with this thermostat on my Heil Gas pack on my first floor - it was a breeze. Now in need help wiring the second floor heat pump thermostat replacement....

On the second floor I have an electric heat pump.
The heat pump compressor is outside and there is an "A-coil" in the attic.

The wiring on the current (old) thermostat is this:

red color wire ==is connected to== R == terminal
green color wire ==is connected to== G == terminal
yellow color wire ==is connected to== Y == terminal
orange color wire ==is connected to== O == terminal
white color wire ==is connected to== W2 == terminal
Black color wire ==is connected to== E == terminal

The problem is this - installation booklet says

"...if your old thermostat has Y1, W1 AND W2 wires, stop now and contact a qualified contractor for help".


I don't have "Y1, W1 AND W2 wires", just W2. Should I get a qualified contractor?

Their diagram then goes on to show the W2 wire connecting to the AUX terminal in the thermostat. Do I connect my white/W2 to the AUX terminal? All the other wires seem to match up easily - so except for this W2 warning in the instructions, I think I would be done. However is there something I'm not considering that warrants a professional installation? Your advice on if I can complete the wiring myself????

Here are the available terminals in the new Honeywell RTH7500D thermostat:

C
G
Y
O/B
RC (jumpered to R)
R (jumpered to RC)
AUX
E
L

The instructions diagram for heat pump read:

C terminal = C or X or B wire
G terminal = G or F wire
Y terminal = Y or Y1 or M wire
O/B terminal = O or H or B wire
RC terminal (jumpered to R) = RC or R wire
R terminal (jumpered to RC) = R or V or VR wire
AUX terminal = AUX or W or W1 or W2 wire
E terminal = E or X or X2 wire
L terminal = L or F wire

[Jay11J]

No need to call, we are here to help.

Old-stat----------new stat.

R-----red-----Rc/R
G----green-----G
Y-----yellow----Y
O----orange---O/B
W2---white----Aux
E-----Black----E

Do you have an extra wire in the wall we could use?

[seDIYgal]

The only wires that were attached are the ones listed above.

Looks like there are 2 other wires coiled around the wire-bundle, but are not being used. One is light blue and one is orange-red (brown?).

What did you have in mind?

[Jay11J]

Take the unused light blue wire and wire it to C, and go to the air handler and wire that to C as well.

Then the t-stat will run on power rather than batteries all the time. And, if the battery went dead, you won't come home to a cold house.

[seDIYgal]

OK. Which is the "air handler" unit - The heat pump compressor is outside and there is an "A-coil" in the attic.

[Jay11J]

The air handler is the unit that has the A-Coil inside of it.

[seDIYgal]

gotcha - thanks! I'll give it a try. you've been very helpful! And I appreciate your quick responses

[Jay11J]

Glad to help out.. Come on back if you have any questions.

[sblinder]

I have a heatpump system with the main unit sitting outside of course and then the rest of it in my attic. I called my heating guy because I am putting in a new thermostat, a Venstar T1800 programable one with Insteon support (home automation available control) Anyway everything went well with wiring until I came to a white wire which was labeled E. When we used this system my heating guy always said to slide the mode over to emergency heat as that would give me the best heating for my situation. Nowhere on this new Thermostat is there a place for an "E" Wire. Wire spots available are as follows.

W1/O/B
Y1
G
Misc2
then two empty ones not labeled
R
C
All of these are over on the right side of the thermostat panel
On the left side is the following.

W2
Misc1
RS2
Misc3
RS+5
RS1
RSGND

There are three Misc jumper strips
Misc 1--Manual says used to set for 3rd stage heating
Misc2--Manual says used for a Dehumidification device
Misc3--Manual says for Humidifier.

I dont have any of these, I called the place I bought the thermostat from and said what do I do with the jumpers on these rows, they had no idea and the manual does not say what to do if you are not using these jumper strips so I just took the jumper completely off each strip, not sure if this was the right thing to do.

The place I bought the thermostat told me the E wire (white wire) I have from the old thermostat should go to the W2 terminal on the new thermostat. Well when I power the unit up I am getting some heating out of it by putting the thermostat manually in Emergency heat mode; however the heat coming out of the registers is not nearly what it used to be which tells me i did something wrong. Also the unit when I tried cooling our main room with a southern exposure with a temp of 77 degrees (outside temp 30) would not blow cold air like it usually will. I am sorry the post is so long , I just wanted to give as much info as possible. My old thermostat is a robert shaw that says its a two heat and 2 cool.The venstar has a good explanation at this url....Venstar Thermostat - INSTEON Remote Control Thermostat 7-Day Programmable - Smarthome

If anybody could help I would appreciate it, my heating guy is never reliable, I can never get him to come out, he always says maybe next week, I am to busy and I try to ask a question and he does not recall every installation he did.

Thanks for reading
Steve Blinder
South Dakota

[Jay11J]

I have a heatpump system with the main unit sitting outside of course and then the rest of it in my attic.

What is your back up heat source? Gas or Electric?
Is your heat pump a single stage or two?

The E wire can be wired to the Misc 1. Then set the jumper for W3.

Let me know what you got for system.

[sblinder]

What is your back up heat source? Gas or Electric?
Is your heat pump a single stage or two?

The E wire can be wired to the Misc 1. Then set the jumper for W3.

Let me know what you got for system.

My system is a Heil, of course a heatpump with the unit sitting outside, in my attic above is all the duct work and an electric stage that is supposed to kick in when the heatpump can't keep up. My heating guy told me that to run this unit I should just run it in Emergency heat mode which seems like I am defeating the purpose of having the heat pump since the electric element must be doing all the heating.

I hope I have not done any harm by not having jumpers on those Misc jumper strips. The system cools perfectly and when I set it in emergency mode via the thermostat it does heat. I have seen the display at times show aux heat that shows up when the spread between room temperature and set tempurature is lets say more than five degrees. Normally when the system is in the emergency mode you can smell a slight hot smell, it has always been this way. I have always been concerned the attic was going to start on fire, but I guess I have to trust in the heating guy.

I really appreciate your help, this thermostat was very expensive and will become part of an Insteon automation system which enables you to control the system from any area of the house and just do lots of stuff.

Steve

[Jay11J]

I just want to be sure you got your jumper/switch set to Elect, HP.

Then in Step 16, CPH, set that to 3.

20=1
21=1
22=1
23=0
24=0
25=0

I have to admit, this is the most complex/confusing t-stat I've ever seen! Way too many settings, and steps to do those settings..

electric stage that is supposed to kick in when the heatpump can't keep up.

Correct.

My heating guy told me that to run this unit I should just run it in Emergency heat mode which seems like I am defeating the purpose of having the heat pump since the electric element must be doing all the heating.

Let the heat pump do the job, you have two extra stage electric heat to help.

Bout the only time you want to run E heat if you get freezing rain, when it's really cold out that the heat pump just can't keep up anymore.

this thermostat was very expensive and will become part of an Insteon automation system which enables you to control the system from any area of the house and just do lots of stuff.

What would you want to do with the t-stat from other areas of the home?

[sblinder]

Jay, if you check out this message board you will see what us crazy home automation people do to our homes. The thermostat when tied to the system can be programed without using the thermostats internal programming, this may seem like no big deal but it is when you want to call home and your system answers the phone, gives you the tempurater and everything else the thing will do, from that information you can make decisions on what you want to do with your house from your mobile phone, web browser, ect.

You can also have a button programmed on a decora style pad with 6 buttons to turn all the lights off in the house, set the thermostat for away mode, and then it could open the garage door and as you are leaving it sets the alarm system. Just weird stuff like that. We just take what the thermostat can already do and tweak it a bit, thats really all its about.

I really appreciate your help and I will give your suggestion a try. Does it matter that I leave the jumpers that were on from the factory on those other jumper strips?

Sincerely
steve

[Jay11J]

Jay, if you check out this message board you will see what us crazy home automation people do to our homes.

LOL Yeah, I live with one who is kinda a geek about it.. We have the X10 system, and the computer runs the timer to turn on the lights, and Christmas stuff! I told him to stay away from my HVAC! :-) I have the Honeywell IAQ, and you could hook that up to a phone modular if you wanted.

I really appreciate your help and I will give your suggestion a try.

Glad to help out. I've never been around this type of set up, so I hope it works out of what I suggest, if you find that step 23, 24, and 25 is not to your liking, go ahead and change it. I don't like the ideal of that far of temp swing before those stages are called for.

Does it matter that I leave the jumpers that were on from the factory on those other jumper strips?

the unused Mics ones? Yeah, those can be left alone unless you have a variable speed furnace or a humidifier?

[sreknthm]

Hello,

I have a wiring question for a programmable thermostat I bought for my Heat Pump. It's a Honeywell RTH7000 Series.

My current heat pump thermostat has 8 wires: G, Y, E, C, O, R, W1, and W2. The instructions say "If your old thermostat had Y1, W1, and W2 wires, STOP NOW and contact a qualified contractor for help."

The new thermostat has the following terminals:
C
G
Y
O/B
RC (jumpered to R)
R (jumpered to RC)
AUX
E
L

The wiring instructions for a heat pump are:
RC terminal (jumpered to R) = RC (or R)
R terminal (jumpered to RC) = R (or V or VR)
O/B terminal = O (or H or B)
Y terminal = Y (or Y1 or M)
G terminal = G (or F)
C terminal = C (or X or B)
L terminal = L (or F)
E terminal = E or (X or X2)
AUX terminal = AUX (or W or W1 or W2)

Any help is greatly appreciated.

V/R
Arun

[Jay11J]

My current heat pump thermostat has 8 wires: G, Y, E, C, O, R, W1, and W2.

What is the make and model of your current t-stat?

[sreknthm]

Hi,

It's a Bryant t-stat. There is no model # on the outside, but on the inside it says

"Part Number 34427DP108
3AAT84B14A1"

Thanks.

V/R
Arun

[Jay11J]

but on the inside it says

"Part Number 34427DP108
3AAT84B14A1"

What brand is the unit inside? I tried looking for that number and came back with nothing.

Is your back up heat gas or electric?

You may have to remove the cover on the unit and make notes of what letters the color wire falls on in the unit from the t-stat. Also maybe same with the wire from outside unit.

[sreknthm]

Thanks for your help so far. I wrote everything down, so I'll just provide it all in case it's helpful.

Panel on front of unit:
Bryant
BDP Company (Division of Carrier)
Model: 517B030010HPFC
Serial: 0179A00033
Product No: 517BN0030010ABAE
Volts: 208/230
Phase/Hz: 1/60
Refridgerant: 32
Motor HP: 1/3
Motor FLA: 3.6
Design PSIG: 300

Single Supply Circuit:
L1 Motor FLA __ Heater Amps 37/39.9
L2 Min Ampacity 50/54.4 Max Overcurrent Protection 50/60
Dual Supply Circuit:
Empty

Terminals on the inside:
W3 (not used)
Y (has a blue wire leaving which connects to electric company box on side of unit)
W1
G
W2
C
O
R
E

Outside wire (wire color-->where it goes):
Brown-->W2
Blue-->W1
Redish-->R
Orange-->O
White-->C
Green-->terminated
Yellow-->converts to a blue wire and goes to electric company box on side of unit

Inside wire #1 (wire color-->where it goes):
Blue-->W1
Green-->G
Red-->R
White-->C
Yellow-->Y

Inside wire #2 (wire color-->where it goes):
Blue-->terminates
Green-->terminates
Red-->E
White-->W2
Yellow-->O

Hopefully this makes sense to you...

V/R
Arun

[Jay11J]

I am not able to find the manual for any of these model# I'm guessing they are older units?

Do you have a digital camera to post the wire diagram on the unit?

The one is throwing me is the "E" on the air handler.


T-stat----A/H-----HP

Y---------Y---box---Y
Aux------W1-------W1
G---------G
E-------W2-------W2/E (?)
C---------C--------C
O/B------O--------O
Rc/Rh-----R-------R

[sreknthm]

At least I don't feel so bad for not being able to figure it out myself. I do have a digital camera, but it says I don't have the ability to post attachments. Not sure where I can change that setting on this website. (I assume you would like the wiring on the t-stat?). I will look around at how to post pictures.

My unit was most likely installed back when the place was built in 1985. I think the heat pump was updated ~8 years ago.

Also, I noted that the outside of the old t-stat shows:
"Part Number 34427DP108
3AAT84B14A1"

But the inside (one the wiring panel) states:
34427DP107
3AAB82B14A1

Not sure if that helps any.

Thanks for your time so far.

V/R
Arun

[Jay11J]

At least I don't feel so bad for not being able to figure it out myself. I do have a digital camera, but it says I don't have the ability to post attachments. Not sure where I can change that setting on this website. (I assume you would like the wiring on the t-stat?). I will look around at how to post pictures.

The photo needs to be uploaded to a image host site, then you copy the direct URL from that site, then here click on "insert image" in the tool box above in your reply box. Paste the URL in the pop up box.

[sreknthm]

Sorry it took so long to find my camera. It's a little fuzzy, but should be read-able. G, Y, E, C are on the top, W1 is on the left, O is on the bottom, W2, R are on the right.

Thanks in advance.

V/R
Arun

[Jay11J]

I'm afraid the photo did not make it on your post.

[sreknthm]

Sorry about that. See if these one of these two links below work.

Wiring Picture picture by sreknthm - Photobucket

http://i993.photobucket.com/albums/a...hm/wiring1.jpg

V/R
Arun

[Jay11J]

Can you take a photo of your air handler wire diagram inside the unit.

On the air handler

E matched up with E t-stat?
W2---" "----W2
W1---" "---W1

[sreknthm]

Unfortunately it's small and worn, and my camera isn't good enough to take readable picture (it's from 2001). However, I will write it out below:

There are three wiring connections: Indoor t-stat (one left), HPT B (on bottom), and LVT B (on right). Both the Indoor t-stat and HPT B go to the the LVT B

Indoor t-stat (--> to LVT B):
R-->R
E-->E
W1-->W1
Y-->Y
G-->G
O-->O
C-->C
W3-->W3
W2-->W2

HPT B (--> to LVT B):
R-->R
E-->E
W1-->W1
Y-->Y
O-->O
W3-->C
W2-->W2

LVT B has:
R (--> to Red color wire)
E
W1 (--> to Violet color wire)
Y
G (--> to Orange color wire)
O
C (--> to Brown color wire)
W3
W2

Not sure why it shows W3 wires when on the air handler the W3 terminal doesn't have any wires connected to it (see earlier post on wire colors and air handler terminals).

I will try to see if I can scan in the paper and post it later.

V/R
Arun

[Jay11J]

There are three wiring connections: Indoor t-stat (one left), HPT B (on bottom), and LVT B (on right). Both the Indoor t-stat and HPT B go to the the LVT B

What's LVT B, and HPT B?

Try to do this for an example.

T-stat----color-----A/H----color---HP

T-stat=thermostat
A/H=Air handler.
HP= Heat pump.

[sreknthm]

It says that LVT B means Low Voltage Board (assuming it means the A/H terminals) and HPT B means Heat Pump Board (assuming these are the wires going to the Heat Pump).

t-stat --> color --> A/H terminal --> color --> H/P
R --> Red --> R --> Red --> ?
E --> Red --> E -->
W1 --> Blue --> W1 --> Blue --> ?
Y --> Yellow --> Y --> (*note 1 below)
G --> Green --> G -->
O --> Yellow --> O --> Orange --> ?
C --> White --> C --> White --> ?
W2 --> White --> W2 --> Brown --> ?
W3 unused on A/H

*note 1: has a Yellow wire coming off the Y on the A/H terminal which switches to Blue and connects to the Pepco Box on the side of the A/H unit (Pepco is my Electric Co.)

My heat pump is on the roof, so I can't get to those wires very easily. I think I would need to get a key from the condo office during office hours, but not sure if they would even let me up there.

V/R
Arun

[Jay11J]

Ok, thanks making it clear for me. :-)

No need to go up to the unit on the roof, there should be 5 wires going up to that. But, does the condo take care of the units on the roof like making sure the coil is clean and what not??


T-stat----A/H-----HP

Y---------Y----------
Aux------W2-------? (Never seen two sets of wire for heat form HP)
G---------G
E----------E--------
C---------C--------
O/B------O--------
Rc/Rh-----R-------

[gac34]

Hi!

I just installed a Honeywell RTH7600 and I am not sure it is running properly. When the heat comes on, it sometimes says "Aux Heat". I was told that means our heat pump is not working correctly?

I reaplaced a Honeywell VisionPro TH8000. I copied down the how it was wired and I converted that to the new thermostat. I am just concerned about the AUX Heat. Any suggestions?

THis is how it is wired now.
Blue Wire --------C
Green Wire ------G
Yellow Wire -----Y
Red Wire --------R and Rc (with jumper)
White Wire ------Aux and E (with jumper)
Orange Wire ----O/B

Thanks for yor help.

[Jay11J]

I just installed a Honeywell RTH7600 and I am not sure it is running properly. When the heat comes on, it sometimes says "Aux Heat". I was told that means our heat pump is not working correctly?

Is the HP running none-stop, and you see Aux light up, or when did you see the Aux come on?

I reaplaced a Honeywell VisionPro TH8000. I copied down the how it was wired and I converted that to the new thermostat. I am just concerned about the AUX Heat. Any suggestions?

Did you get an outdoor sensor?

What is your back up heat? I'm guessing electric? Also, do you know the KW rating for the Aux heat, and do you have an extra wires in the wall?

So far it's wired up right.

[gac34]

Is the HP running none-stop, and you see Aux light up, or when did you see the Aux come on?

No, AUX just comes on in the morning after we had the heat set back for the night.

Did you get an outdoor sensor?

No

What is your back up heat? I'm guessing electric? Also, do you know the KW rating for the Aux heat, and do you have an extra wires in the wall?

Yes we have a electric backup heat. No I don't know the KW rating.

I have heard that with a heat pump it is better to set the temp on the thermostat and forget about it. Meaning, not to set it back when we are not home or when were sleeping. Is this ture?

[Jay11J]

On most case, yeah it's true that it's better to set it and forget it.

If you get an outdoor sensor for the new t-stat, you can lock out the Aux heat when it really not needed.

It's normal for Aux to come on in the morning since HP don't recover fast like gas heat does, so that's why lot of us stay "set it and forget it".

If you have an extra wires in the wall, we can stage the Aux heat. (Aux wired by itself, and E wired by itself.) If you don't have extra wires in the wall, then the jumper will have to stay.

[Sam2010]

Hi, i was just replacing an old thermostat for my heat pump and would like some help with the wiring

old thermostat
white wire to "x"
green wire to "g"
red wire to "r"
yellow to "y"
blue wire to "b"
black wire to W2
then a wire runs from W2 to E

new thermostat options are
C
G
Y
O/B
RC
R
Aux
E
L

would appreciate help
Thanks

[Sam2010]

Honeywell RTH7600

Hi, i was just replacing an old thermostat for my heat pump and would like some help with the wiring

old thermostat
white wire to "x"
green wire to "g"
red wire to "r"
yellow to "y"
blue wire to "b"
black wire to W2
then a wire runs from W2 to E

new thermostat options are
C
G
Y
O/B
RC
R
Aux
E
L

would appreciate help
Thanks

[hvactechfw]

old -COLOR-new
R-RED-R
B-BLUE-O/B
Y-YELLOW-Y
G-GREEN-G
W2-BLACK-AUX AND JUMPER TO E
X-WHITE-C

IS YOUR SYSTEM A RHEEM/RUUD/WEATHERKING?

[Sam2010]

thanks for the response... this is what i tried not exactly as you suggested (is it wrong?)
old - color - new
R - red - R
B - Blue - O/B
Y - Yellow -Y
G - Green - G
W2 - Black - Aux
X - white - E

i didn't put a jumper to E

it seems to be working this way but am i wrong?

i currently have a Rheem but it's old and want to change heat pumps. would appreciate any suggestions on which brand is best?

[hvactechfw]

X is most likely a common so I would change that immediately so you don't accidentally switch to E heat and pop a fuse or transformer.

brand really doesn't matter as much as installation quality. I prefer trane over others, but this is just my opinion.

[Sam2010]

thanks again, made the switch and seems to be working well. every installer seems to be pushing a different brand (Trane, Amana, and Carrier thus far).