Heat pump thermostat wire color code

[@Cdsare4squares]

This video helped me understand the 8 wire system and what it really did was help me install my NEST e Thermostat. I was struggling for about a week to install this thing and was wondering why my heat pump wasn't kicking in, and now because of this video I saved $100 from having someone come here to swap a couple wires. Thank you so much for this video!

[@electriccar3253]

Happy new year. GFM

[@mckennabrad]

Do your remember the setup for the Nest? I’m struggling to find a good install example for my 8 wire heat pump on the Nest.

[@b_rad334]

Got a picture of your wiring I’m fighting with mine with 8 wires?

[@tiffanyhenderson195]

@@mckennabrad did you figure this out? I am looking as well

[@juiceman37160]

Any of yall got an answer lol I'm on a nest too and can't get it done😂

[@TandNServices]

Hey GFM, just depends on the part of the country your from. Here in Ga. we always use blue for common. Orange is the reversing valve wire doesn't matter when it gets energized. If I'm doing a 2 stage cooling unit I use brown for the second stage.

[@howling_hollow_farm.]

Thanks for this. We have been roasting for years because they just want to replace our system in our area instead of diagnose issues. Was able to get my thermostat wired correctly and get some cool air in my home

[@grayfurnaceman]

There are so many options on how pumps are wired that I'm not sure all of them can be covered, but you are right in most cases. More coming on this. GFM

[@billybbob18]

Blue = C. Low volt common Red = R. Low volt power Green = G. Fan White = W. Furnace heat Yellow = Y. Compressor Orange = O/B reversing valve Black = aux/em heat. Electric strip heat. Please follow the above standard. I've looked at at least 1000 units, and this is what I see on average. Modern units handle the staging in the control board. If there are multiple stages, then we jumper them together at the control board and let the unit itself handle the logic involved in controlling the stages. I've only seen black used as a common a few times when a tech messed up and shorted one of the stat wires. To cut stat wire, I like to gently score the outer jacket, then gently bend around the scored section to finish pulling it off. There's zero reason to have shorted wires in the stat wiring.

[@jollyscaria1922]

Good thankyou ineed 220v pleas explanningneed

[@Balticblue93]

Finally, someone properly trained. This is exactly what you do and how you wire your system. Unless it is a 2 or four wire communicating thermostat and system from Carrier /Bryant or any other brand. The wires still stay the same at the system board, but the thermostat like the Carrier Infinity or Bryant Connex Evolution can use the four-wire set, if needed. Because as Billy posted that the control board will handle the logic for the various stages of the equipment. Black is used for a replacement wire or dual-fuel setups that do not have a communicating thermostat and board.

[@grayfurnaceman]

I have that coming. It will probably be a series of videos. Thanks for the comment. GFM

[@grayfurnaceman]

One of the early problems we had was when the heat pumps stats came out with a B term. The installers were used to B for common. So they hooked it up and when the stat called for heat, the transformer failed. Thanks for the thoughts. GFM

[@grayfurnaceman]

Certainly true. I will be doing more on this that includes thermostat, air handler and outdoor unit options for wiring. Thanks for the thoughts. GFM

[@cruzingpapa]

Trane XR13 single stage heat pump with two stage aux heat pack in air handler. Here is what commonly used. Red=24v, Blue=24v common Yellow=Energize heat pump contactor Green=Blower relay Orange= Reversing Valve White=1st stage heat Black=2nd stage heat and defrost board call for heat while defrosting On Carrier I have seen white used mostly as common , in my area. But you should always check because there are it seems, a lot of color blind installers. Home owners think they can save money by replacing their own t-stats but mostly they wind up calling a service tech anyway after they have blown either the low voltage fuse or the transformer in the air handler/ furnace.

[@grayfurnaceman]

Obviously, there is a lot of variation here. The only problem I see with this method is the use of Blue for common is that if your pump has the reversing valve energized in cool (Rheem), and with the B terminal on thermostats, Often the blue(common) is connected to B on the stat which will blow the fuse or take out the Tformer. Thanks for the thoughts. GFM

[@Balticblue93]

@@grayfurnaceman In my 25 years, I have never seen a Rheem/Ruud here in Denver with the blue wire on the B terminal. Broncos colors Orange and Blue. Orange is always the reversing valve and blue is common back. But I have never seen a Carrier with white as a common either. I sell Bryant Evolutions and the new Amana's these days. I did see an Oxbox made by Trane the other day and it energizes the heat pump in heating mode, but regular Trane units do not. That was interesting to clean up on the wiring.

[@abelely]

What do you hook the blue to on a thermostat if you have 8 wire heat pump

[@skyym3629]

I always remembered orange for the summer cause the sun and blue for the winter cause snow. This is how I always remembered wich wire for what kind of reversing charge. I know the sun is yellow and snow is white, but it always helped me when I was like 14. Sounds like you been doing this since you were a kid also. I remember only like maybe 12 A/C companies in the valley then. Now there are literally hundreds. Thanks.

[@nicoibarra2445]

Does one of the black ones can be goes solo not on switch Thanks for the help

[@jimreilly917]

If working on an older unit, pay more attention to the way the board is wired in the air handler. Most often this is followed but sometimes it’s not, for whatever reasons.

[@grayfurnaceman]

I think the reason for us using blue for rev valve is the the terminal letters. B=blue O=orange. It would be nice if we had a sensible color code used throughout, but that is not happening. Thanks for the info. GFM

[@mikemc8495]

The B is when the reversing valve is energized in heat o is for energized in cooling

[@Squarekn0t]

I am a 75 year old HVAC mechanic, I go all the way back to coal heat, I have to say "I hate Heat Pumps" When they came out in the 80's I steered most of my customers in the Mid-Atlantic zone away from them if they wanted to be warm. Now the new high efficiency furnace with pc boards aren't much better as far as plenum temps are concerned. The fans turn on 60 seconds after the burners. I guess it's time to retire and sit in front of my pellet stove!

[@grayfurnaceman]

I am a 73 year old tech and have mostly the opposite experience. lol I started my career in heat pumps in 1977 in a location that had electric rates as low as .075 cents. They only became less viable when electric went up and gas went down. The high efficiency gas furnaces have the same 120F plenum temp as gas designed furnaces always have had. The fan delay is 30 to 45 seconds which matches older 1980 style furnaces because the heat exchangers are thinner and heat up faster. Maybe it is best to stay by the pellet stove. I also get cold easier with age. GFM

[@Squarekn0t]

Yes Amen to the pellit stove. Actually when I moved into my double wide at the beach I switched to the Hydro-Sil baseboard units. Zoned out the house so I have heat where I want it /when I want it. The best is the bathroom that I keep at a constant 74'. My towel rack is right over it so I always have a hot towel. My bill here in Delaware is $130 a month on a preset billing. Thank's for the reply. PS If I die tomorrow my relatives will come and dig me up so I can do another install gratis. Thank god I never gave up my account at RE Michaels

[@habanalibre7275]

MUCHAS GRACIAS. Una clase magistral! Muy agradecido!

[@handyman4uservices]

the black is often used for emergency heat. and yellow means compressor.............

[@nicoibarra2445]

@@handyman4uservices Does one of the black ones can be goes solo not on switch

[@romeparrilla8307]

nice video,but can you please help me connect them wires on my hvac heat pump non programmable thermostat my actual wirings are red,green,yellow,blue ,white.and the thermostat is c,o,b,w/e,w2, thank you very much....

[@floridasaltlife]

Thanks for the great videos on HVAC, very helpful...

[@electriciandallastx9182]

Thanks for the thoughts you have provided here.

[@XLILPTX4ELON]

So i have a heat pump, and a gas furnace. I have 5 wires in my thermostat, Blue, Green, Yellow, Orange & Brown. How do i switch to EM Heat, on thermostat? Do i need another wire?

[@richardbertrand2770]

Good video ,thanks for the info

[@flyingmonkey3822]

So lifting the white wire would stop running that expensive aux heat?

[@GalaXy808]

Hey sir thank you for sharing this. I never know this wiring basic things.im learning

[@guitar6411]

Thank you so much! i didn't have my white wire hooked up.. I have heat now!

[@grayfurnaceman]

Life is good when you are warm. GFM

[@bloombrews]

Dr.! Thanks for all of your Vids... The "Black" wire, is "usually", used from the Defrost Heat-Pump board, to complete the circuit of the "X", back to the the Air-Handler, to bring on the Electric Toaster Strips, during a Defrost Cycle.....? This is the normal "AUX" call, when you see the Stat, call for this also...!?? Grasshopper

[@grayfurnaceman]

Around here we use the white for that because we usually use white for heat and the defrost heat can go to the white at the air handler. We save black for common. No real accepted color code. GFM

[@morro115]

can this thermostat can be use on 2 wire furnace??

[@grayfurnaceman]

Yes. Just use R and W. GFM

[@ar7223]

Blue and yellow can be put together on the thermostat ?

[@armandmariano1828]

Doug, my new thermostat for a heat pump system has ob and W in one slot. Can w and OB be combined?

[@grayfurnaceman]

Yes. GFM

[@mosescortez6204]

New to the channel, so hey . Its just a question about my thermostat wont kick on. My old sears heater for our home. If i touch wites its sparks, but will not go otherwise. Any suggestion aside from just gettinga new one.

[@MrThePachuco]

i'd say yellow is a signal wire for condenser and green is indoor fan but im glad you clarified B O ive been looking for the best way to put that but also wire colors aren't universal the terminals are important so WRYGBOW^2y^2

[@shirleycummings3020]

I have had two new carrier thermostats in the last 3 years, and still is going on and off, and at times the temperature is crazy set at 68, and it is reading 74?

[@grayfurnaceman]

You're welcome GFM

[@Zeheria]

we have a package unit A/C and Heater. we had to have our fan replaced at the top of the unit and since then we can not switch from A/C to heat. we have called out techs from our warranty company and they say that there is a break in our white heating wire and advised us to switch orange to orange on the unit and swap the orange and white wire place on the thermostat to manually go from A/C to heat. it is not working for us.... we have called on this 3 times. 1) how can I make this work 2) we want to get this broken wire fixed, do we need to replace the whole thing, what is general pricing in your opinion? your response is greatly appreciated. Thank you!

[@grayfurnaceman]

+Zeheria Zan What kind of warranty company do you have? This appears to be their problem, not yours. I would be on them the make it work. GFM

[@russ92x1]

Ok I have heat pump/ac with heat strips in air handler as emergency/aux heat. I just purchased a nest learning and can't get the aux heat to kick on. I have orange and brown wire. Connected orange to o/b and white wire is in W1 and brown I assumed was the wire for the heat strips and put it in W2/aux. When I turn on aux 1 heat nothing happens but if I put it on auxiliary heat 2 the furnace kicks on and it feels like there's warm air coming out of it. so any idea what I did wrong and how to correct this?

[@shirleycummings3020]

If there is a nick on the white wire behind your thermostat plate, could this be causing the thermostat to go blank(no power) to it, then coming on a minute later?

[@grayfurnaceman]

The nick will not cause no power, but sometimes the wire inside the insulation is broken and will make intermittent contact. You can find the break by looking for a loose spot in the wire. GFM

[@stevec2753]

Fantastic job...can you go over the latest info regarding variable speed blowers vs multi-speed blowers? Also, where does the conversion to DC come into play regarding the newer variable speed blowers...I've been told that newer variable speed blowers actually run on DC , is this true and if so, why would they go to DC power? Thank you for this series and sharing your knowledge with us..

[@jollyscaria1922]

Good welcome my sife iam jobes somanney side thankyou good

[@dealtdamage7693]

blue is common (c), red is (rc rh) jump them together if your not sure orange is (o) on majority of brands *** excludes RHEEM RUUD then you would hook to (b). If it has a b/o terminal then hook to that and follow book to program it to energize those terminals in heating instead of cooling. green is fan (g) white is (w2) Black and brown are either outdoor air temp sensor (on newer houses) typically going to an s1/s2 terminal. If they are not connected on the old one then do not connect. If they are connected to W1/e then re-use, if you dont have a w1/e then stick them with the w/2 which will be a bitch but will help energize your heat strips on a call for E-heat. Yellow goes to Y1 or if you have a y/y2 then that on carriers. Do not do this with the air handlers power on. You will blow a fuse or transformer and have to spend even more money on a n hvac tech to come to your house. 💪🏻

[@aakozanoglu]

I have a Ruud AC from 1988. Last week I replaced my old mercury type round Honeywell thermostat with no programmable simple digital Honeywell thermostat (RTH5160). Since then my AC does not work. Outdoor unit is quiet both compressor and fan. Only indoor fan comes on.I had B Y G R W on old thermostat. Connected B to o/b on the new one. I don't think I have a heat pump. I tried leaving black B wire not connected, it did not make a difference. What might have caused no-ac situation? I couldn't find a fuse in my furnace. I replaced both fan and run capacitors too.

[@Balticblue93]

Recently, OxBox a Trane company also decided to change their wiring on their heat pumps. No idea why they would do that on their contractor grade equipment. They energize in heating mode.

[@DanielByrns]

Question on my old thermostat my Black and white were both on the W in the panel? why was that?

[@grayfurnaceman]

The white is probably heat. The black could be to power a humidifier. GFM

[@kinghammurabi1882]

I enjoy your videos very much Gary . When wiring a condensate pump equipped with a safety switch in a heat pump system ,where would you wire the safety wires to? Terminals O or Y ? Thank you

[@grayfurnaceman]

Put the switch in series with the Y circuit. GFM

[@jollyscaria1922]

Thankyou good welcomed gues

[@kirtlowry443]

On my rheem heat pump thermostat my black wire is not on the E in the thermostat. It has been taken off by the previous owners. Is that a problem? Please help. Ty.

[@Trollberg]

I have 8 wire all are connected to the terminals except for blue. The brown is connected to X terminal. Would my nest thermostat work in this system with heat pump? and where does the Brown or X wire go to?

[@electriccar3253]

Can't tell you for sure, it depends on the system and the original thermostat. GFM

[@brandonturpin8932]

Need advice for a nest 3rd gen. I have blue and orange left over with no for sure answer as to where they need to be plugged

[@grayfurnaceman]

Where were they placed on the old thermostat? GFM

[@kinghammurabi1882]

What connections at the stat would you touch together in order to activate the reversing valve in a cooling mode heat pump? O-Y ?Thanks

[@janenorendavis9721]

I am replacing a Honeywell TH3210D1004 for my heat pump system with a Honeywell TH9320WF5003. The 3210 has separate wires going to separate E and Aux ports. The 9320 combines E and Aux into a single port. Which wire from the 3210 goes into the 9320 E/Aux port? What is done with the extra wire? If it helps, the wire color currently going into the E port is black and into the Aux port is white.

[@DanielByrns]

Mine is same why did you ever figure it out?

[@rb5235]

You do a good job with you teaching videos. Thanks! Have you any dealing with a Nest thermostat?

[@grayfurnaceman]

I haven't done anything so far, but I will when I can. Thanks for the support. GFM

[@rudy2ndjr]

Hello is it possible to use 5 qires with a heat pump? Any help

[@SombraLocs]

I was told that Y1 should be first stage heat and cool and that one difference is one will also energize the reversing valve. I thought you should always use W for heat, but now I'm confused.

[@grayfurnaceman]

There is no always in this business. On some stats W1 will be backup heat. On some, Y1 will turn on the reversing valve, and Y2 will be cooling. Alll you can do is look at the wiring diagram to see how it is wired. GFM

[@SombraLocs]

grayfurnaceman I was asking because I seen thermostats with no W terminal, in this case how would Y1 work as heating in heat mode?

[@grayfurnaceman]

SombraLocs If there is only a Y1 and no Y2, then Y1 is both heat and cool. In this case, the reversing valve will be energized by the system switch. GFM

[@Balticblue93]

@@SombraLocs Just out of curiousity, what thermostat did not have a W terminal at all? I have never seen that before.

[@SombraLocs]

@Kevin Bowman 😂😂😂😂😂 this was 8 years ago. I believe I was still in the process of starting HVACR school. Man, time flies.

[@Jizle05]

I have a honeywell thermostat(batt powered) with 4 wires coming out(red,blue,white, and green) going to an old singer electric furnace. The spots to hook the wires on the furnace are labeled C,G,R, W1 and W2. I have red on Rc&R(jumpered), white on W and green on G. For the furnace I have green to G, white to W1 and red to R. The think that has me confused is that there is no yellow wire for the cooling. This also throws me off to where the two wires(red&white) goes to on the board. I only have the red with red at the furnace. I know the white should be with yellow, but I don't have a yellow wire nor spot on the furnace for it. Any help will be very much appreciated!

[@grayfurnaceman]

The problem here seems to be there is no yellow wire. If the blue is connected to the Y on the stat, then the blue can go directly to the condensing unit of the air conditioner. There is no need for a connection at the furnace. If the white is connected to W on the stat, it should go to W1 on the furnace. Hope this helps. GFM

[@Jizle05]

I decided to replace new stat wire going from the thermostat to the furnace. I have red, green, yellow and white in the proper slots. For the furnace I have G-G, W-W1, Y tied to white from condenser and R-R along with the red wire from the condenser tied on to the board as well. As of now nothing is coming on...

[@nnormman]

Hello! I really need your help, I have a white Rogers it has 8 wires ,L,E,C,w2,G,YR,andO/B

[@pamkaturi]

I am replacing my old thermostat with a Honeywell rthl2510c, my old terminals are as follow: X-black O-orange Y-yellow W2- light blue and white G- green E- brown R- red New terminals are: B. O. G. Y. W/aux. NOt used. R. Rc. Any advice on how to connect it properly. Also how do I know if I have an auxiliary heat pump or not? Thanks

[@grayfurnaceman]

pamkaturi O to orange, Y to yellow, G green, E brown not sure, R and Rc jumper Red. If you have an outdoor unit you either have an air conditioner or a heat pump. You can tell if it is a heat pump by the number of wires going to the outdoor unit. 2 wires, you have an air conditioner. 5 or more, its a heat pump. Hope this helps. GFM

[@geraldchuks3275]

Just wondering why he keeps avoiding to answer any question regarding the black wire. He answered the other colors and disregard the black one. So let me ask where does the black-× wire connect to in the new thermostat?

[@groverknoll2900]

I purchases a Honeywell 7 day thermo.model RTH2510B showing the use of 4 or 5 color coded wires for use with my GE heat pump (running 35 years w/out repair) using aa GE Weathertron thermo model T344D100M179. The Weathertron has 4 hg bulbs with 2 white wires on left and only 1 on right.Please advise wiring instructions. I have pics but don't know how to send.

[@mrcrazy3872]

ok what if u have a 6 wire system for heating and cooling then how do I wire it, and what kind of thermostat would work any cheap one as long as it has cooling and heating or do I need a special one that well wire a 6 wire system ,the thermostat looks 100 years old its big and brown, so I don't now if I should even touch it cause everything is working but I would like to get a much simpilar one ,which I can set the heat or cooling and leave it alone ,thanks for any help

[@grayfurnaceman]

mrcrazy3872 I need to much more about this system. Can you send pics of the wiring at the thermostat? GFM

[@mrcrazy3872]

it wont let me post any pic on the message o well my luck.

[@mikeinpcola5543]

Nice video.

[@J.G.3]

I bought a new thermostat that has no terminal for the E wire which is Emergency Heat. They told me I need to combine the E wire and the W2 wire with a wire cap and run another wire from the cap to the W2 terminal. What type of wire cap and wire do i need to get?

[@grayfurnaceman]

+D Foxworth I have no idea what a wire cap is. Perhaps they are saying to connect both wires to W2. GFM

[@billnolan1411]

Can you put a Maples Chase thermostat 9601 for heat pump on a ;forced air gas furnace with no AC ? thanks

[@grayfurnaceman]

I believe you can. Just hook up the r and the w and place the system in em ht. Hope this helps. GFM

[@thesmoothjazzguy2012]

grayfurnaceman I have a question regarding demand defrost boards, I know that with demand defrost, there has to be a certain temperature differential between coil and ambient to start a defrost. How many degrees exactly is this differential?

[@grayfurnaceman]

It depends on the manufacturer and the age of the unit. It must be below freezing and the one's I have seen were about 15 degrees, but no quote on that. The newer units are have smaller differences. Hope this helps. GFM

[@thesmoothjazzguy2012]

Thanks. I know the difference between coil and ambient temperature is 15-20 degrees when the coils are not frozen, but it seems like it would be a lot more for the defrost to initiate.

[@grayfurnaceman]

John Smith With ambient at 30 degrees,and 20 degree split, that would give an evap temp of less than 10 degrees. At that point, the compression ratio of the compressor is very high and efficiency goes way down. I would think that if the unit is newer, it would be even less than 15 degrees. I don't have any factory specs on these parts. GFM

[@thesmoothjazzguy2012]

I think that my TXV on my 2 ton Trane XE 1200 is busted. On heat mode, it's maintaining a differential of 40 ( when it should be 15-20) and it's triggering the demand defrost when it's not even frozen.

[@grayfurnaceman]

John Smith I would first look into refrigerant charge. GFM

[@karessalovins3196]

How do I hook up my throats ate I have a red blue green and white coming out of wall

[@davidparker1377]

OK - I am replacing a thermostat that has both an E terminal and an Aux terminal - Honeywell TH8320U1008. My new Honeywell TH8320R1003 has a single terminal labeled Aux/E. How do I compensate?

[@grayfurnaceman]

I would just put both wires on the terminal. GFM

[@101ssnow]

I used to have a heat pump but replaced it with traditional condenser unit. need to know how to wire up the emergency heat option. Honeywell does not know.

[@flk3rd]

Scott did you find your answer?

[@freyalove3831]

Very helpful. Thanks

[@grayfurnaceman]

+Freya Love Welcome GFM

[@bardinkurtis]

so if there's a wire on o the reversing valve is energized in cooling no matter what? and if it's on b it's energized on heating no matter what?

[@grayfurnaceman]

+kurtis bardic You got it. GFM

[@antoniodgo100]

I have a 6 cable witch is orange ,blue .white,yellow,green and red I’m trying to connect a Vivint element smart thermostat but I can get it to blow cold air it seems to cool the house but not as good as with the other thermostat that I’m removing Can you please help ?

[@malophxable]

I have a question my new package unit is blowing cold air even on heat mode so I check my wiring on termostat and I notice I have R,Y,W,G,C but c is not connected out side on unit. am I missing a wire here? is a electric rheem classic package unit also unit and compressor works just fine but like I said heat mode blows cold air. TIA

[@grayfurnaceman]

The C terminal is probably not the problem. I would look for breaker kicked off first. Could also have elements or sequencers failed. GFM

[@freyalove3831]

I have a little issue with thermostat. When I turned "heat" on my thermostat, the heat mode didn't come on( left on 15 min). Then, decreased below temp 68F (my thermostat actual reading) to 63F and kicked in cool mode( appeared 2 snowflakes on my screen) and blew in cold air on HEAT setting. I checked the wire system, I tightened the blue wire and make sure nothing is loose. Still the heat mode didn't come on.

[@freyalove3831]

+Freya Love BTW I live in south Florida and has a heat pump. I'm clueless where the heat pump switch is located.... Super clueless.

[@freyalove3831]

+Freya Love Do you think it might be a thermostat malfunction ???

[@jacobdroesser1255]

How do you run the thermostat wire for heat pump unit pdoes it go fromthe thermostat to unit then from there to outside unit or what need help

[@grayfurnaceman]

The indoor air handler is usually the central part of the connections. The thermostat takes power from the air handler, and distributes it back to the air handler and the outdoor unit. Hope this helps. GFM

[@jonathanabraugh2356]

I disconnected my old thermostat, blue and brown were not used. I just hooked up my new Honeywell RTH3650D using the same wires, left out blue and brown. The outside compressor(?) thing comes on, but it's not working. The pipes are cold and the vents are just blowing cool air. What's going on? Assuming I have it hooked up correctly (at least as far as the instructions are concerned), what could be happening?

[@grayfurnaceman]

I assume you have a heat pump. You may not have set the changeover valve correctly in the installer setup. Check the advanced par of the manual. Hope this helps. GFM

[@jonathanabraugh2356]

Yeah, I do have a heat pump. I think I did all that. I went over and over it. And even called the help number.

[@grayfurnaceman]

Jonathan Abraugh Turn it to cool. if it heats, the reversing valve is hooked up backwards. GFM

[@jonathanabraugh2356]

I set it to cool, it blows cold air and the pipes get really cold. So that's working normally I assume. Anything else come to mind?

[@grayfurnaceman]

Jonathan Abraugh Not that I can think of now. GFM

[@ScubaSteve0224]

Have you ever seen a grey wired used? I'm looking to update my thermostat to the Nest and I have the following wires hooked up to the old thermostat. Red, Grey, Yellow, Green and White. Someone please tell me what the Grey wire is. Thanks

[@grayfurnaceman]

Gray is not commonly used in thermostat wire. The only way to know is to trace it to the furnace to find out where it goes there. GFM

[@ScubaSteve0224]

grayfurnaceman thank you so much for replying. I looked a little closer and on the thermostat terminal for the grey wire it has C for common. I know I was kinda shocked when I seen this because C is usually blue but this house was built in the early 80's so maybe grey is all they had available that day. Do you think it could be mislabeled by chance?

[@grayfurnaceman]

The thermostat color code is not universal. also, sometimes another wire that is usually used for common had an open. So you kind of love the one your with. GFM

[@ScubaSteve0224]

Got ya, thanks for your help. Have a great day.

[@antoniokristler6973]

You've eliminated all options other than the black wire so I would assume it would be common, depends on if whoever installed it did it right though :s.

[@jonathanriesco1]

Thank you for the information. I got a Honeywell RTH111 thermostat and the old thermostat wasn´t there, but the house has a heating well. Now, I have a cable with 8 wires. I got the red, yellow, green combination, but I still have the orange and blue wire. Do I need to connect both or witch one?n

[@grayfurnaceman]

There is no way to tell for sure without seeing the application, but heating only red and white. Fan green, cooling yellow, orange and blue are mostly used for heat pumps. GFM

[@nnormman]

Now I have a nest witch has 10 connections y1,y2,Go/B,Rc,W1,W2aux,C,*andRH?

[@Anhangel]

Can you help me repair my electric bycicle?

[@ejmyatt7308]

I just watched another video. He explained the yellow wire as the compressor wire, not the cooling wire. Any advice?

[@blakehollingsworth839]

Same difference!

[@christianmohammed3619]

would a blue is connected to red it work????

[@grayfurnaceman]

Probably not. What are you trying to do? GFM

[@christianmohammed3619]

I am trying to make auxuillary cord with old head phones

[@Manda22Sue]

Can you tell me how to hook this up to the nest 3rd generation

[@grayfurnaceman]

It does get a little complicated. The O/B terminal changes the heat pump from heat to cool. Is that where your problem lies? GFM

[@AngelMedina-ie7eg]

I have Red to R Blue to Y White to W Green to G Brown to 0 What does the brown connect to? My AC works, but the heat fan doesn't. Help me please.

[@grayfurnaceman]

In your case, if it is a heat pump, the brown is to the reversing valve. GFM

[@michaelkranz2529]

Wire color means nothing , you can use any color you want to as long as the wires terminate in the correctly , " Y " to. " Y " etc ... What happend is long ago people just started using red for " R " because red starts with the letter " R " and so on , there is no rule that says you have to use a certain color to designate a specific terminal on equipment

[@grayfurnaceman]

You are correct. But we have adopted a loose color code to make it easier to troubleshoot and install. GFM

[@michaelkranz2529]

True , I just wish it were mandatory to use specific color code , and have the inspector verify upon inspection , I would take some of the guesswork out of diagnostic work .

[@grayfurnaceman]

Most of the inspectors I know would be lost trying to do that. GFM

[@raptorclaw7]

As stated wire color is meaningless. If you don't know what a terminal does then you shouldn't be messing around with anything on you furnace, or AC or heat pump.

[@bkd-newyork]

can someone suggest me with Honeywell classic (round one) and i have only two wires, black and white. i tried to insert black to black and white to white but boiler does not work. Alternatively, i connect white and black with hand to keep it running so basically thermostat does not work. Any suggestions please...

[@grayfurnaceman]

Set R to one wire and W to the other. GFM

[@aplusmhs]

So for only heat...R, W & B?

[@grayfurnaceman]

It depends on whether the reversing valve is energized in heat or cool. GFM

[@pppjourneyonabike5992]

What is a common wire (black)?

[@grayfurnaceman]

It, of course, could be any color but most commonly will be black or blue. GFM

[@cuitzeo12]

I'm having trouble with a goodman air handler I have 5 wire thermostat cable on the unit R,W,G,Blue,Brown and I have 4 wires on room thermostat R,W,G,Blue and I have 2 wire from the Ac unit I need help I burn the fuses like 4 times can you help me

[@ronaldjohnson4470]

Thank you sir.

[@grayfurnaceman]

+Ronald Johnson Welcome GFM

[@emmanueladu4356]

What about brown

[@grayfurnaceman]

There is no specific use for brown, but it is commonly used as a second stage of backup heat. GFM

[@bloombrews]

Just read the Posts..........If You think that the "color" of the wires "Lost", Your thinking, So Do We..."Sometimes".!

[@forge52100]

What if you only have 6 wires? I don't have the orange or the black, but have the brown. I jumped red, yellow, and green and the AC came on. With the controller it would operate the heat, but not the AC. The outside unit would come on in AC, but the inside fan would not. Anyway, my wires are as follows on the controller, R-Red, O-empty, B-Blue, Y1-Yellow, E-Jumped to W2, Y2-empty, W2-White wire and jumped to E, G-Green, C-Brown, L-empty. It's a Protech controller. Since I jumped red, yellow, and green I hope a new controller will fix it. Thanks.

[@killer92293]

What. Is. The gray. Wire.

[@killer92293]

Mine has. A gray

[@votteoman]

does anyone know how to wire a central heat and air that only has emergecy heat. no hear pump. I need a diagram for this.

[@grayfurnaceman]

Check my channel for diagrams. I have several there. GFM

[@flk3rd]

I do not see the one that answers Chris's question

[@CellufunLover]

wish I knew how to get my heat to work :-( by this it looks hooked up right but it's still freezing

[@grayfurnaceman]

+Mary Lethco Usually wiring is not the problem if the unit has been running normally. All breakers and fuses ok? GFM

[@CellufunLover]

grayfurnaceman the fan is moving outside but not blowing out

[@grayfurnaceman]

+Mary Lethco Check the fuses for the outdoor unit, also the panel breaker. GFM

[@CellufunLover]

I would just like to update you on the issue. It was the internal motor that was bad and also low on fluid

[@grayfurnaceman]

+Mary Lethco Thanks for the update. GFM

[@ITSJUSTBERG2020]

Did something wrong house is spinning backwards.😭

[@ejcheck]

I wanted to change the thermostat on my Carrier based Heatpump sytem and I have encoutered issues. The current thermostat is a Comfort Zone II (master) with a 2nd zone slave thermostat. The wiring to the master is nothing as described and has only 4 wires Blue (RS-), Red (RS+), Green (VG) and Purple (V+). I have called Carrier and theyve told me Ithat they're wifi thermostats will not work on it and in any event I would have to talk to a contractor. Called Honeywell, and they told me there's wouldn't work. Called a local contrator (in NC) and they told me the control boards and dampers would have to be changed to change thermostats - ~$2500 Any thoughts would be appreciated

[@grayfurnaceman]

Elliot Check Unfortunately, there is not any cheap way out of this. The Wi Fi stats work ok with single zone systems, but with zoning its a professional job. GFM

[@ejcheck]

And extremely expensive Thanks for the help

[@shannonsharp4235]

There is NOT a color code for wiring! IT GOES BY FUNCTION! I WORK FOR HONEYWELL AS A TECHNICAL SUPPORT FOR WIRING RETAIL THERMOSTATS! DO NOT GO BY COLOR! GO BY WHAT TERMINAL THE WIRES ARE IN!

[@grayfurnaceman]

It is true that not all units follow color code. But to say there is no color code is chaos. You must start somewhere and that place is with the color code. Sometimes, when a thermostat or equipment is replaced, the number of wires used is not the same as the original. Also, we have indoor air handlers and outdoor units with their controls. Yes there is a color code. And we use it when we can. Thanks for the thoughts. GFM

[@shannonsharp4235]

While I can respect what you are saying, I guess all I can ask is that when people are asking for advice on wiring up a thermostat, please make sure that we are telling them to also watch for what terminals the wires are in, because I can not tell you how many systems I have had a phone call on because they ONLY wired by color and because the installer of the system used a blue wire as a common and they place it into b for blue....so on and so forth....and I wish that there was a different labeling for "RC" because I have also had a number of people place the "C" wire in the RC terminal because they didn't have a "C" on their thermostat because it was run on batteries only and they didn't bother to read the directions.

[@pecmapmUA]

"Rc" + "C"- 24V DC ? "Rc" "C" 24V AC? How right?

[@javiermontes3777]

What happen if I connect black and white together

[@carlosleiva9406]

@@javiermontes3777 I believe nothing will happen because black is just a common

[@billy99100]

Nailed it

[@coreymcniel3390]

you can learn from inplix plans how to make it by yourself.

[@richarddeno9898]

WELL THAT ANSWERS ALL MY QUESTIONS, BLAAAAA.

[@sloanhouseholder6169]

Brown is common on rheem

[@426superbee4]

a b c d e f g h red goes w blue goes to RC omg what a mess

[@jujuchiha]

Spit it out man

[@TheGrubmiester]

And the brown wire goes where, you never say

[@grayfurnaceman]

The brown wire could be used for any additional application. There is no specific use for this wire. GFM

[@armandorueda4615]

is good

[@grayfurnaceman]

Thanks for the support. GFM

[@armandorueda4615]

Thanks you for help

[@shirleycummings3020]

This thermostat is not cheap, it cost close to 400.00

[@caseyconrad9931]

you left me more confused then before I watched this... why not just go in order of the wires.. "this one is sometimes always this, this one is sometimes this, but not always, this one is this, but not always.... come on guy...

[@grayfurnaceman]

Casey Conrad Guess what. There is no universally used color code. Not everyone uses the same wires for the same thing. This is just a guide to what is commonly done. GFM

[@michaelhouser3123]

Wrong the brown wire is a signal wire if your going to explain the wires and what there for at least do it eite

[@grayfurnaceman]

michael houser The color code for control wiring is not set in stone. This video gives a common method but is by no means always used. There is no method that is universally accepted. GFM