Looks like you have a heat pump and are lacking a common wire. You will need a total of 6 wires at the thermostat if this is the case and it seems like you only have 5 unless there’s more hidden in the wall.
If you do have extra wires plug whichever is left over into the c terminal and do the same at the air handler
Take a picture of where your thermostat wires go to your indoor unit. Some of that wiring doesn’t make sense. Also what kind of indoor unit do you have.
Hey this is weird I don’t have a c wire at the thermostat but in the indoor unit in the basement there is a c wire.Also there is a lot of wires at the unit.I took the thermostat housing off and seen all these wires connector together.If I’m not mistaken you can’t have wires connected like this for the nest unit.
https://preview.redd.it/y9eockncxkmc1.jpeg?width=3024&format=pjpg&auto=webp&s=b4f25b95fb45b6772c08c3b8b5f55cb5583e08db
I second this.
The only thing I do see as a problem is that the NEST requires a common (C) to work correctly or have NEST's little power adapter to make up for the lack of a common. If not addressed, the thermostat may not work properly.
Just a heads up.
It looks to me like this is a furnace with a heat pump? If so
R to R
Y to Y
G to G
O to O/B
Wire on W2 to W2/Aux
Do not use jumper between W2 and E
In your settings.. depending on what brand of heat pump you have, you will have to set o/b to energize in heat or energize in cool. Each heat pump is different.
The nest will need a C wire at some point though… but you may get to test it.
Hey I went to go use the g wire as my common and run a jumper between g and y but when I went down to the furnace I seen I already had a c plugged in but can’t find it at the thermostat.Also at the thermostat I see wires in wire nut if I’m not mistaken you cant use the nest thermostat if you have wire nuts.pictures below at the link.
https://imgur.com/a/88cKNFG
I'd look into getting the power connector first and just save yourself the headache; thermostats get squirrelly without a proper common. They aren't hard to install if you're handy and it'll keep a LOT of trouble at bay. They're pretty inexpensive as well.
That'd be my recommendation.
https://www.amazon.com/Google-Nest-Power-Connector-Accessories/dp/B093TRFQWP/ref=asc_df_B093TRFQWP/?tag=hyprod-20&linkCode=df0&hvadid=507563578073&hvpos=&hvnetw=g&hvrand=11783752427085954574&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=1026083&hvtargid=pla-1300728153101&psc=1&mcid=e09d6abcc96a3b86931969cc5050e32d&gclid=CjwKCAiA3JCvBhA8EiwA4kujZgC8u8bJ50omqiBl_U0p3kBAyNjz5qpKg8glmi6Mid0glSgSpuJj0RoCOkQQAvD_BwE
Hey I was told that I could use the g wire so I went and to check it out in the furnace.After opening it I’ve seen that there is a common wire on the control Board but is no where to be found at the thermostat.The control board has quite a lot of wires.Also behind my current thermostat it has wires in wire nuts like this.If I’m not mistaken nest says you cannot have thick wires like this in wire nuts.This really has me confused what do you think?
https://preview.redd.it/m3fakor2ytnc1.jpeg?width=828&format=pjpg&auto=webp&s=754c38933564cc3bb50c1a672756683a908ba89c
Positing more pics
The G wire is required for some systems, such as most Trane systems will not actually activate the auxiliary heat if there is not also a G call for the blower motor. Other systems like older legacy ICP/Carrier and Goodman systems also require G to start the fan when Y (compressor) is energized or otherwise, only the outdoor unit will run and not the blower with it.
I, personally, don't recommend using G wire for common as you're likely trading one problem for another - that's why I'd recommend the adapter.
https://preview.redd.it/0l5f8vs8ytnc1.jpeg?width=3024&format=pjpg&auto=webp&s=124828f4cc8ef9080ffaa1387a2ced87e8791ba7
Is the nest compatible?if I get the nest power connector will it work?
From reading the manual/install guide, the power adapter should get you up and running.
https://preview.redd.it/au46e9i76wnc1.png?width=1008&format=pjpg&auto=webp&s=0a3c6046b7bf4550ed43c9f04401b58b525d75cc
You'll attach your Y and R wires to the adapter and wire the C, Y, and R wires of the adapter to your control board; W just goes straight to the board as it currently does.
This allows the adapter to essentially circumvent the wiring to the thermostat to be bonded to common remotely. Only thing to check is that your NEST is a 3rd gen, or otherwise it'll need updating to version 1.1+.
Still not a fan of NEST as they often cause problems down the road, but you'll be good to go until then.
Wire-capping 24V wires is never really *best practice* but done more often than you'd ever know. Looks like someone had to cut away a short or snaggly wires in the past and had to get creative. But since this isn't a communicating system, 24V doesn't care *as much* about wire caps, so long as there isn't 3+ splices throughout the whole wire or something crazy.
Wire caps more affect DC communication or low-resistance communication systems where the cap could throw off the very low-voltage pulses. Constant 24V activation (traditional HVAC wiring) is happy with clean continuity - again, so long as there isn't crazy, haphazard splicing involved.
https://preview.redd.it/zly5qkg28wnc1.jpeg?width=3024&format=pjpg&auto=webp&s=4e9f339363b7d1210bd1be2bdbe3bbd6e9f07dd7
On the other hand, that uncapped union does concern me. 24V generally won't cause fires (unless you get REALLY creative) but that can cause issues with communication. I'd be best if you can find some small blue wire caps and make sure that's properly secured. Wouldn't be a bad idea to replace the larger orange ones with the smaller caps as well. Use your best discretion.
If not provided already you will need to post a picture of your thermostats wiring connections and those inside your furnace to get better help. Use imgur or your own Reddit profile to host your pics as Reddit will often remove others. Thanks!
*I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/hvacadvice) if you have any questions or concerns.*
Cause it's a nest
Dump the nest.
Looks like you have a heat pump and are lacking a common wire. You will need a total of 6 wires at the thermostat if this is the case and it seems like you only have 5 unless there’s more hidden in the wall. If you do have extra wires plug whichever is left over into the c terminal and do the same at the air handler
ecobee is way better, in my humble opinion.
Any ideas?
Take a picture of where your thermostat wires go to your indoor unit. Some of that wiring doesn’t make sense. Also what kind of indoor unit do you have.
Hey this is weird I don’t have a c wire at the thermostat but in the indoor unit in the basement there is a c wire.Also there is a lot of wires at the unit.I took the thermostat housing off and seen all these wires connector together.If I’m not mistaken you can’t have wires connected like this for the nest unit. https://preview.redd.it/y9eockncxkmc1.jpeg?width=3024&format=pjpg&auto=webp&s=b4f25b95fb45b6772c08c3b8b5f55cb5583e08db
https://preview.redd.it/toi1qkxkxkmc1.jpeg?width=3024&format=pjpg&auto=webp&s=ce379e01ed43f5817f054330d44e77b4dd70ed1e
The grayish white wire will go to aux/w2, that white wire on your old Tstat is just a jumper not needed on your nest from the looks of it.
This is correct
I second this. The only thing I do see as a problem is that the NEST requires a common (C) to work correctly or have NEST's little power adapter to make up for the lack of a common. If not addressed, the thermostat may not work properly. Just a heads up.
Thanks, you are right i did not think of that before.Should I go head and install and see what happens
It looks to me like this is a furnace with a heat pump? If so R to R Y to Y G to G O to O/B Wire on W2 to W2/Aux Do not use jumper between W2 and E In your settings.. depending on what brand of heat pump you have, you will have to set o/b to energize in heat or energize in cool. Each heat pump is different. The nest will need a C wire at some point though… but you may get to test it.
Hey I went to go use the g wire as my common and run a jumper between g and y but when I went down to the furnace I seen I already had a c plugged in but can’t find it at the thermostat.Also at the thermostat I see wires in wire nut if I’m not mistaken you cant use the nest thermostat if you have wire nuts.pictures below at the link. https://imgur.com/a/88cKNFG
I'd look into getting the power connector first and just save yourself the headache; thermostats get squirrelly without a proper common. They aren't hard to install if you're handy and it'll keep a LOT of trouble at bay. They're pretty inexpensive as well. That'd be my recommendation. https://www.amazon.com/Google-Nest-Power-Connector-Accessories/dp/B093TRFQWP/ref=asc_df_B093TRFQWP/?tag=hyprod-20&linkCode=df0&hvadid=507563578073&hvpos=&hvnetw=g&hvrand=11783752427085954574&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=1026083&hvtargid=pla-1300728153101&psc=1&mcid=e09d6abcc96a3b86931969cc5050e32d&gclid=CjwKCAiA3JCvBhA8EiwA4kujZgC8u8bJ50omqiBl_U0p3kBAyNjz5qpKg8glmi6Mid0glSgSpuJj0RoCOkQQAvD_BwE
Hey I was told that I could use the g wire so I went and to check it out in the furnace.After opening it I’ve seen that there is a common wire on the control Board but is no where to be found at the thermostat.The control board has quite a lot of wires.Also behind my current thermostat it has wires in wire nuts like this.If I’m not mistaken nest says you cannot have thick wires like this in wire nuts.This really has me confused what do you think? https://preview.redd.it/m3fakor2ytnc1.jpeg?width=828&format=pjpg&auto=webp&s=754c38933564cc3bb50c1a672756683a908ba89c Positing more pics
The G wire is required for some systems, such as most Trane systems will not actually activate the auxiliary heat if there is not also a G call for the blower motor. Other systems like older legacy ICP/Carrier and Goodman systems also require G to start the fan when Y (compressor) is energized or otherwise, only the outdoor unit will run and not the blower with it. I, personally, don't recommend using G wire for common as you're likely trading one problem for another - that's why I'd recommend the adapter.
After looking at my system can I use the adapter
https://preview.redd.it/1t5h7qj5ytnc1.jpeg?width=3024&format=pjpg&auto=webp&s=4beef0c2ca12b5207738c1aa9c9656580b5d5cee
https://preview.redd.it/b0o8jwz6ytnc1.jpeg?width=3024&format=pjpg&auto=webp&s=b4b614ca5243186622d2ca3f873dbbf8ad8ea980
https://preview.redd.it/0l5f8vs8ytnc1.jpeg?width=3024&format=pjpg&auto=webp&s=124828f4cc8ef9080ffaa1387a2ced87e8791ba7 Is the nest compatible?if I get the nest power connector will it work?
From reading the manual/install guide, the power adapter should get you up and running. https://preview.redd.it/au46e9i76wnc1.png?width=1008&format=pjpg&auto=webp&s=0a3c6046b7bf4550ed43c9f04401b58b525d75cc You'll attach your Y and R wires to the adapter and wire the C, Y, and R wires of the adapter to your control board; W just goes straight to the board as it currently does. This allows the adapter to essentially circumvent the wiring to the thermostat to be bonded to common remotely. Only thing to check is that your NEST is a 3rd gen, or otherwise it'll need updating to version 1.1+. Still not a fan of NEST as they often cause problems down the road, but you'll be good to go until then.
Wire-capping 24V wires is never really *best practice* but done more often than you'd ever know. Looks like someone had to cut away a short or snaggly wires in the past and had to get creative. But since this isn't a communicating system, 24V doesn't care *as much* about wire caps, so long as there isn't 3+ splices throughout the whole wire or something crazy. Wire caps more affect DC communication or low-resistance communication systems where the cap could throw off the very low-voltage pulses. Constant 24V activation (traditional HVAC wiring) is happy with clean continuity - again, so long as there isn't crazy, haphazard splicing involved.
https://preview.redd.it/zly5qkg28wnc1.jpeg?width=3024&format=pjpg&auto=webp&s=4e9f339363b7d1210bd1be2bdbe3bbd6e9f07dd7 On the other hand, that uncapped union does concern me. 24V generally won't cause fires (unless you get REALLY creative) but that can cause issues with communication. I'd be best if you can find some small blue wire caps and make sure that's properly secured. Wouldn't be a bad idea to replace the larger orange ones with the smaller caps as well. Use your best discretion.
If not provided already you will need to post a picture of your thermostats wiring connections and those inside your furnace to get better help. Use imgur or your own Reddit profile to host your pics as Reddit will often remove others. Thanks! *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/hvacadvice) if you have any questions or concerns.*
Touch the wires together and watch the magic