How to install Nest smart thermostat with Taco zone panel.(switching relay)

How to install Nest smart thermostat with Taco zone panel.(switching relay
In this video we explain how to wire a Nest thermostat to a Taco zone panel
using 2 wires and 3wires with rib relay. smart thermostats do not work well with zone panels so we give you a quick solution, we also explain a 2nd option which uses a rib relay. plz subscribe and like. Email us or comment with any questions.
nest.com/
www.tacocomfort.com/products/e...
www.functionaldevices.com/
Climate Shield Heating & Cooling LLC
www.shieldhvac.com
[e-mail]
[phone]

[@shaileshprajapati9945]

Thank you for this video. I purchased a home last year that came with the Taco 3 zone relay and had only R and W cables. I was wondering how to connect to my new nest thermostats. This was very helpful. I connected my today and everything works perfectly well.

[@shielduniversity419]

Im glad it helped

[@ABlackMorman]

@@shielduniversity419 my com is all the way to the left how do I do it then?

[@shielduniversity419]

@@ABlackMorman run a wire to the left or attach it to the existing wire with wire nut

[@danielmcdonald5965]

I think that's my solution as well. You've got the RIBU1C in your video. I believe I should use the RIBU2C for 2 zones and use the 24VAC COM on the left the same way you connected the relay with the C wires on each zone. Is that correct?

[@ryankelly4462]

I'm fairly certain I have the same zone relay. I know little to nothing about resistors and am looking to pick some up to try this solution. Is there a specific resistor I should be looking for?

[@tomvarnham7487]

Thank you for making this video, it helped me to successfully get my thermostat hooked up and stopped the thermostat from giving me the error message!!

[@lilcoody1]

*Works great: **Fastly.Cool** and Warming environment perfectly controlled. I use 3 in different grow tents. It’s nice to see from your phone how your tent temps are. Does High and Low and records data.*

[@hongoshroom6708]

Thank you for the vid bro. Iv been stuck on this issue and Your the first to tackle it ! I’m gonna try this out later and let you knw how it goes.

[@shielduniversity419]

Your welcome. Glad it helped.

[@tedjohnson1009]

Thanks so much! I don’t randomly comment. My problem is slightly different but your video taught me enough to sort it out!

[@shielduniversity419]

Im glad it helped

[@danbyrd9088]

You. Are. Awesome! Many thank yous!

[@80660018]

Very nice. A how to video that actually shows how to

[@megannamojlik7696]

Great video explaining it!

[@Pinnovators]

Thanks for the video! I had to use a 500 Ohm resistor to make my Nests work properly. The 1K caused some erratic behavior and false triggering on the Taco.

[@shielduniversity419]

Sorry that it gave you trouble. I'm glad you found the exact problem.

[@mikeryan7012]

Which Nest model were you using?

[@Pinnovators]

@@mikeryan7012 I’m using 1 gen 3 and 4 Nest E.

[@carolineteo2950]

Thanks for the video!! I have a Taco 3 zone relay but each zone have 2 thermostat terminals for R & W only. There is one 24V COM terminal on the upper left corner in the panel. I have 3 t-stats, 2 for heat and a separate air conditioning unit in the attic, 1 is heat only. The t-stats were battery powered digital t-stats until last year. Last year I attempted to replace the 2 heat & air digital t-stats with Sensi smart t-stats without c-wire. The Taco experienced with flickering light. I ended up replacing only 1 heat & air t-stat without c-wire and the heat only t-stat with a c-wire connecting to the 24V COM terminal in the Taco panel. The flickering went away. It's difficult to run new wires from the panel to the 2 heat & air t-stats. Last week, I ran 2 c-wires (one from each air conditioning in the attic) tapping into the c of the transformer in the air handlers. I connected this new c to the air & heat smart t-stat. No complaint from the Taco panel. However, when I attempted to replace the last heat & air digital t-stat with a new Sensi smart t-stat with a c-wire, the Taco made loud noise and one of the zone light went on red. I saw your reply to one of the comments that when there are two or more smart t-stats connected to the Taco it might not work. Do you think this could be resolved if I insert a resistor between the W terminal and the 24V COM terminal (currently has a wire inserted for the heat only smart t-stat) for the two zones connected to the heat & air smart t-stats, since those two t-stats have c-wire from the air-conditioning? Do you see any issue with tapping into the c in the air handlers to provide 24v steady power to the t-stats? Please let me know your thoughts. Many Thanks!

[@carolineteo2950]

Just an update, I just tried the resistor, it doesn't solve the issue.

[@loversrlair]

Thanks for posting this video for ensuring me I am not the right person to do that which I have been trying to do for last 6 hours

[@frenchonion3359]

I have this issue on a new boiler install i have an sr506 with priority.. i dont have common on my low voltage side, just r and w.. do i need a different relay?

[@richcarter9476]

Thanks for the video. I have two wires to my thermostats and need a c wire to keep the Nest's powered up. Does connecting this resister between the W and C terminals in the zone controller accomplish this?

[@shaun8566]

I am moving to a home that has a three zone boiler. One zone for baseboard upstairs, another for baseboard downstairs, and the last for radiant floor downstairs. There is a separate thermostat for each zone and each zone has its own circulator. Right now everything is operated off mercury thermostats and I was looking to replace the existing thermostats with the Nest Learning Thermostats. (I do not utilize the learning features so I am not concerned with using the Nest for the radiant zone) I was going to upgrade to the Taco SR506-EXP-4 and was thinking that everything would be alright since there is a separate common terminal for each zone. I was expecting that I could simply wire RWC from the thermostat to RWC on the switching relay, however now you have me second guessing myself. What would need to be done to utilize three Nest thermostats successfully?

[@mattdeniston7068]

Thanks for this video! My setup is a little different, hoping for some advice. I have a radiant floor heat only (no AC, no fan) and trying to replace my old thermostat with new wifi thermostat. Thermostat wire has 4 wires, only red and white currently in use by old thermostat. On the other end, I've got a Taco ZVC403-2 where 2 of the three zones are in use. On the ZVC403-2, there is no C or common terminal, just a two "T" terminals where the red and white tstat wires are currently connected. So, I think I simply need to get 24V to my tstat using one or two of the spare tstat wires not in use (there's a green and blue). My first attempt was running a jumper wire from the "COM" terminal on the lower left of the ZVC403-2 (middle terminal in set of three labeled N/O, COM, N/C, in wiring diagram labeled as "Dry Contacts") to the green spare tstat wire and then connecting that green wire on the other end to the "C" terminal on the thermostat. That didn't work (tstat didn't get powered). My second attempt was running that same jumper to the upper left of the ZVC403-2 to the left terminal of the "Power In" 24VAC (coming from 24V transformer). This powered the new tstat, but as soon as tstat called for heat, the tstat stopped working. Have photos I can share. Thanks in advance for any tips!

[@sonarsan]

I have two AC units on the attic and two heating zones for my range house. I connect Nest thermostats for each zone but each thermostat can work only either with AC or a heat connected. When I connect both heat and AC the thermostat gives me E79 or E74 errors. But when a thermostat is connected to only heat it works without a resister. What would be the best option for my setup? Does it mean that if we decide to go with a relay option we need to have one relay per zone?

[@almitchell6012]

What if its saying no power to RH, I installed 2 nest learning tstat about 2 years ago worked fine up until about 4 or 5 weeks ago. Then 1 stopped working saying no power to RH, i have side hooked up to cool and the other to heat, i have both RC & RH connected.

[@noazhivago6012]

Would this work with an Sr503? Thanks!

[@EricS59]

Hi, I was wondering if you could help me on video with providing power to my nest thermostats. I have 2 Taco boxes connected to my boilers. New home I purchased and afraid to mess things up. I will of course glad;l’y compensate you for your time. Thanks.

[@timothynorton644]

TACO very clearly talks about this in their instruction sheet for the ZVC404 Zone Valve Control (search "TACO 102-393" for instance) but it's always good to see a video. TACO includes the resistors (1000ohm, 1/2 W) in the box - so, be careful what you throw out and, as always, if all else fails - read the instructions or tech info that comes with the TACO unit (it's only 2 pages). I am wondering, however, why go the more complicated route instead of just adding the resistor and using a 2 wire setup?

[@kenking4958]

Thanks for making this great video. How do I wire another transformer to keep the nest thermostat charged using the 3-wire/ rib relay configuration?

[@shielduniversity419]

Sorry for late reply. This is a lil complicated and would need to make another video

[@FenwaySausageWorks]

Would I need a rib relay for each zone if they both have a nest smart thermostat?

[@salemilio8869]

Is the Arco panel the same as taco panel

[@paulhamilton6025]

First, thank you for this, I believe it’s going to give me the flexibility I’m looking for. Two questions: with the resistor in place, the led still lights red, but the Nest no longer shows an error, correct? Red led would normally indicate no power to the circulator pump, but in this case it is powered as you demonstrated - correct? Third question, I guess - I can wire each Nest thermostat on the taco in the same way and have Smart Control across the system - correct? Thank you.

[@ItzDonnieDee]

Great video ... My question is will the rib relay wiring method in this video work for wiring the Honeywell T9 to a Taco sr503 zone panel? the Taco 503 has TT terminals where the tstat wires go instead of RWC from the panel in your video... And Can I wire more than one thermostat to the RIBU1C relay? Any help with this will be a life saver, thanks.

[@shielduniversity419]

There are rib relays that may allow you to do 2 thermostats. But it will be difficult if your a beginner. I would stick to one each. Also if your doing more than 2 thermostats I would use a separate transformer to power relays and thermostats

[@jennifereasterday3125]

We’re installing the SR504-EXP with the intention of running radiant cooling as well as the radiant heat. Any suggestions on wiring from the thermostat to the Taco to trigger the heat pump to heat or cool since there is only a connection to control the heat on the Taco

[@shielduniversity419]

Kind if hard to figure out your question with out more info or pics

[@dj5752]

THANK YOU FOR THIS VIDEO. OUTSTANDING. Question: I have a Taco Model # SR503 102-083. IT HAS NO COMMON WIRE SO I WILL USE THE RESISTOR ADD A WIRE AND GO TO THE COMMON PORT TO THE TOP LEFT OF THE RELAY. THIS UNIT HAS ONLY ONE (1) FUSE IT'S A 1 AMP FUSE MAX. DO YOU KNOW THE PHYSICAL SIZE AND IS IT FAST ACTING FUSE OR SLOW BLOW? I THINK THE FUSE IS 30MM LONG. THANKS.

[@theCECkicker]

This video is a God send!!! Thank you! Would this be the same for a TACO SR501 with only 1 zone? Looks very similar. Would the WYZE thermostat have the same setup?

[@shielduniversity419]

Not sure about wyze yet. Should work with the other taco

[@K1KO247]

So now can i use 1 nest thermostats to control different zones ????

[@onexsp1492]

Thanks for the video very helpful, just one question, I have the Sr 506 exp version and I have 4 thermostats, for now I want to install one smart ecobee thermostat, will this work properly if I use the resistor method?

[@shielduniversity419]

I will test it and make a video on ecobee with taco panel. I'll get back to you and make sure it works before I say yes

[@onexsp1492]

@@shielduniversity419 I would appreciate it man, Im subscribing. Thanks

[@shielduniversity419]

@@onexsp1492 Sorry for the delay. I tested the Ecobee, and it is not compatible with the Taco panel resistor method. You would have to use relay with it or run 18/3 wire

[@deepsubmicron]

I have an taco zvc404 with Thermostat terminals labeled T and T . No R, W, or C. Any ideas on how to wire up the Nest? Or should I get a newer model taco Zvc404?

[@shielduniversity419]

If you get a new 1 it has r w and common amd would be easier for you

[@TheArtOfConduitBending]

can you tell me which model nest thermostat you used for this video. better yet could you tell me any 2 thermostat brands that will work with the taco zone controller? Please i would greatly appreciate it.

[@shielduniversity419]

New 5th generation Nest learning thermostat. They sell them at homedepot.

[@shielduniversity419]

Thats what I would use

[@TheArtOfConduitBending]

And it would work with the navien boilers as long as i use the 1k watt resistor?

[@leonelramirez5077]

No one said anything about a boiler on here

[@etp1325]

I have a Taco cvc405. It does not have c connectors adjacent to the R&W connectors.

[@shielduniversity419]

Buy a new board or check my other vids with rib relay installed

[@timmandeville605]

Good morning, I have a Taco SR506 zone panel. 12VDC output on T1 and T2 to a 24VAC transformers that power the zone valves. I want to add wifi thermostats in my home but only have two thermostat wires. Any thoughts on how to add the "C" wire for this application? Thank you (I wish I had the Taco zone panel in this video!)

[@shielduniversity419]

Run new wires

[@Chris-uh3cm]

thanks bro

[@Rilessean]

Hi. Thanks for the video. This is exactly what I needed. One question overall. Why don’t you just wire the “green” common wire directly to the common on the TACO for zone 1? Wouldn’t that provide the needed 24v?

[@valdemarmendoza8572]

I am connecting the Taco 3 Zones. What about ZC and ZR conecction between boiler and Taco switching relay? . I can see you did not connected even the manual requiers it. Whta can we do?

[@shielduniversity419]

This video is only to connect thermostat to zone panel Not how to wire the entire zone panel

[@harismatsas7160]

Hello. I have the SR504 taco relay. It looks exactly like the one in this video but is missing the ”C” common input in each zone. Can I setup Nest thermostats using my taco relay or do I need to buy the one you have in this video? Is there a workaround ? I currently have 4 battery operated thermostats than control my hot water boiler which sends heat to radiators. I would like to switch the thermostats to digital ones and considering Google Nest. Three of my current battery operated thermostats use a 18/5 wire to connect the taco relay but only two wires are connected. The R and the W. The fourth thermostat only uses a 18/2 wire which connects to R and W. What do you suggest I do ?

[@shielduniversity419]

If it was my house I would by new boar to make it easier.

[@turbofroggy]

Use the #1 connection on the zone valve connections for the 24V for the common.

[@jeebolard]

This works for 2-wire setup on an Ecobee, too right? Red/White into R/W at the Ecobee, and just jump W to C on each zone with the 1000 Ω resistor? That's incredible...

[@jeebolard]

Just looked it up… Ecobee thermostats aren’t power stealing, so the resistor method only works on Nest thermostats, or smart thermostats that are power stealing. And even with a nest, the resistor method isn’t all that recommended, because under heavy usage, the thermostat doesn’t have enough time to keep its internal battery charged, leaving an opportunity for the system to fail under heavy load on really cold days or really hot days if you have air conditioning.

[@bluefloyd6058]

Taco makes it easy even with outdoor reset and indirect DHW. Much prefer the Ecobee over the Nest IMHO. Zero need for the relay on either thermostat ;)

[@shielduniversity419]

Thanks for the tips!

[@shaileshprajapati9945]

Also wanted to let you know that Didn’t have the option to put a 1K ohm resistor next to the White cable so I connected it directly to the Com Port without the resistor.

[@sparrow4809]

thanks

[@ldenorio]

my system does not have a zone panel just 2 taco zone valves, can you show how to connect nest with the power connector and 2 taco zone valves with 2 wires only

[@shielduniversity419]

2 wires is almost impossible. Best bet is to run 4 wire tstat wire

[@oliverbork2627]

On the new Nest Thermostat that requires a C wire what do you recommend? When I add in the C wire (normally I just use W and R) it can’t detect the W wire.

[@shielduniversity419]

Do you have the Taco zone panel ?

[@shielduniversity419]

How many wires do you have at the thermostat? Where are you connecting thermostat wires to? Need more info

[@oliverbork2627]

@@shielduniversity419 yes I have the Taco panel. So the old thermostat just used R and W. When I do R and W with the new Nest Thermostat it says it needs a C wire. Guess it is not being supplied enough power. When I added a common wire (C) the thermostat won’t detect the W wire.

[@shielduniversity419]

@@oliverbork2627 this is why I made this video did you watch it. If you use a resistor it should help you. Watch video and subscribe plz. You can even leave the common wire off

[@oliverbork2627]

@@shielduniversity419 When I have just the W and R wire in and a risistor between W and C it sees all wires. But it doesn’t not supply enough power with the risistor. (I already have one transistor on another zone on the board. That is with the Nest E Learning thermostat and it works great). Guess the best option is doing the relay? Since I have 2 zones I want to use a smart thermostat on would you recommend doing 2 relays instead of just doing 1 relay and 1 risistor. Its a great video and it solved my first thermostat, no problem with the risistor.

[@hilide]

Why couldn’t I simply replace the transformer in the multi zone heating relay to a larger va transformer and wire the nests thermostats the conventional way using a two wire system ? I’m adding three gen 3 nest thermostats and only have a two wire to each thermostat

[@shielduniversity419]

Do what ever youd like if you know what your doimg

[@alsufian94]

My nest requires a c wire . I only have R and W . I’m using a a single zone system . Anyway can I connect a c wire to the “COM “on my taco 501 relay to get c wire , the nest recognizes my r and w but needs a C

[@shielduniversity419]

Should be able to but let me check the zone panel first. What is the model number of zone panel

[@shielduniversity419]

Sorry I just noticed you mentioned 501 I will look into this

[@shielduniversity419]

I looked at the manual you should be fine. Just don't mistake any wires and crisscross them.

[@johnleite391]

I have a Taco ZVC403 Zone panel and the thermostat zone connections only have R and W. There is no common. Can I still somehow connect a Smart thermostat? Thanks.

[@aliencat1]

I also have a Taco ZVC403-4, 3 zone controller. My previous thermostats did not have a C wire connection, and the wiring was cut too short for me to easily add one. I used the resistor trick in this video to replace the old thermostats with three 3rd generation Learning Nest Thermostats, without adding a C wire. My system is hydronic radiant floor heating only. Only the R and W wires are used to each thermostat. I bridged a 1K ohm resistor between the C and the R at the Taco ZVC403 zone controller, exactly as shown in this video. The Nest controllers are wired for 2-wire heat, with W1 and RH. All my thermostats are working great, and the internal battery is able to maintain its charge. One important tip, is to charge your Nest thermostat before installing it, using the micro USB connector. In my case, my Nest thermostat was not able to draw enough power to recharge during setup using wifi, so the controller shutdown, due to low power. Pre-charging for 2 hours resolved that issue.

[@johnleite391]

@@aliencat1 Thank. I got in touch with Taco and they were helpful. I would suggest that anyone requiring assistance call their customer support or complete a support form on their website..

[@meltonsmith9833]

I have a ZVC404, is it possible to connect a smart thermostat?

[@shielduniversity419]

I made a video on zone valve panel look for it

[@BILLIARDLO]

Thanks for the video. I have a customer with a five zone, hot water baseboard system. He currently has an older Argo 6 zone controller (AR866) with standard two wire thermostats. There is a third unused wire (green) at each thermostat. He wants me to put in his new Nest thermostats to replace each of the older battery thermostats. Question: Do I need to change the controller and add relays for each new thermostat or is there another way of doing it? How would you approach it? Thank you in advance. Bill

[@shielduniversity419]

I would use a separate transformer for the rib relays, wire R, W and C at thermostat. Use the relay to close the tt on the Argo panel. Remember W will now energize the rib relay

[@BILLIARDLO]

@@shielduniversity419 Thank you. I think I understand. More Questions: For five zones (relays and Nest thermostats) is a 40va transformer large enough? Lastly, what model number relay do I use for each thermostat? To Confirm (as I can't attach my diagram): -From transformer to thermostat - one wire to R and the other to C on Nest thermostat -From RBI to Tsat - White/Blue wire to C and White/Yellow to W -From RBI to TT on Argo Circ Relay - Orange and yellow wires to each Thanks Again. Much appreciated!

[@shielduniversity419]

@@BILLIARDLO yes sounds right noy sure what model rib relay any supply house has them

[@BILLIARDLO]

@@shielduniversity419 Yes, I see in your video they are model # RIBU1C, about $15.00 each. Thanks Again!!!

[@BILLIARDLO]

@@shielduniversity419 Hi There! I just wanted to touch base with you on the job above, in which you helped me. Everything worked perfectly, just as you described. Thank you for your help. Its much appreciated! I have another similar job that I need your input on. I'll describe it in a separate reply, so as not to confuse the issue at hand. Thanks again!

[@peterpavlos]

Good Video what do you do if you have to install 3 smart thermostats in this situations, would u need 3 relays?

[@shielduniversity419]

Yes. And if you notice that the voltage or wifi drops out you may need external transformer to power the thermostats and relays.

[@wilsoncdeoliveirajr3115]

Hi if I have Central Air also connect to the nest can I also do the same procedure or that’s only if it’s heat ?

[@shielduniversity419]

Need more info on what u have

[@wilsoncdeoliveirajr3115]

So I just bought this house and I have with on those Taco panel with 3 zone but also have a Central Air , can I do that same procedure with the resistors and connect with the Centrail Air ?

[@wilsoncdeoliveirajr3115]

I’m a new homeowner so I’m clueless, if I need to do the “use the G wire for C wire “ where is the control board for my burnham oil furnace RSA 125TH-TB? Thank you so much if you can help me with this ...

[@shielduniversity419]

@@wilsoncdeoliveirajr3115 This is very complicated to explain. I would probably have to make a video for this application. There is no G in the boiler. The G would be in the air handler where it blows are for the Cooling On the thermostat RC, Y and G would work of the air handler. RH and W will work with taco zone panel

[@wilsoncdeoliveirajr3115]

@@shielduniversity419 oh I see would be nice if you had a video explaining that I’m hurting my head trying to install my 2 Thermostats and can’t get them to work at all ! Very frustrating but thank you for your time to respond to me ...

[@bokononisti2820]

I'm a little confused. You have a 3 wire low voltage cable running between Nest and Taco. Why not just wire R, W, C at Nest to R, W, C at Taco, and skip the external relay? R and C complete a power loop to provide constant power to the Nest (or any smart thermostat). W is switched on when Nest calls for heat. I have 2 wire from my old battery powered thermostat to Taco zone panel. I wanted to upgrade to smart thermostat and have access to replace the old 2 wire cable with modern 18/5 and thought I could simply connect R, W, C at thermostat to R, W, C at Taco. But this video has me wondering if that would work.

[@shielduniversity419]

Hi. I asked my self the same question. Sometimes you get away with it if you have 2 zones or less. But I found a few jobs that required a relay even though we have more than 2 wires. For some reason it causes voltage issues with zone panel. Relays switch back and forth as if power is dropping and you get errors on nest thermostat. Try it your way first it might work if not you can add relays

[@shaun8566]

How did this work for you? I was asking myself the same question. I am looking to utilize a 3 Nest thermostats, one for each zone in three different zones, and am now questioning if that is going to be an issue.

[@bokononisti2820]

@@shaun8566 Haven't tried it yet. If you try, let us know how it goes.

[@jackiez2689]

@@shielduniversity419 I did that, connect RWC (Taco) to RWC (Nest) direct and it was very inconsistent, wifi works sometimes, but nest indicates missing c-wire all the time. How does a relay help? What is the reason/theory behind it? Gonna try your method!

[@leonvitale6641]

I have a Taco SR503, and it does not have the Common for each zone. It's off to the side of the panel just one. I used the Google Adapter and hoped that would work. It keeps opening and closing my valve taco sentry valve. Sometimes it leaves it open when done heating or ends up closed when calling for heat. Anyone ever seen this?

[@shielduniversity419]

Havent seen it. Need more info or pics

[@SreeVadde]

Thanks for the video. I have the same setup but my nest says no power on R wire. Does this method work for me?

[@shielduniversity419]

Plz elaborate do you only have 2 wires? I need to know more info. What equipment do you have?

[@SreeVadde]

@@shielduniversity419 thanks for the response. Current setup is a two wire. R and W. Though I do have unused green wire. I tried using it as C on both nest and taco zone panel but still not getting no power on R error. Bit more background, I have 7 zone heating with 2 24V taco zone boards. 4 on one and 3 on other. I am having issue with second thermostat on each board. Looks like first one is using up full 24V and shows power on R and W n works fine. From second thermostat on show no power on R error and zone starts even before nest thermostat is put in wall plate. Hope that gives enough details.

[@shielduniversity419]

Did you install the 1k watt resistor from w to c ?

[@SreeVadde]

@@shielduniversity419 not yet. I don't have any on hand. I am checking with you to see it's doesn't cause issues on taco and it works. In my case does the resistor needs to be between W and C or R and C?

[@shielduniversity419]

According to Taco manual it is from w to c. If you have exact same set up as video it should work. Unless you had someone work on it or you worked on it yourself and crisscrossed wires and damaged the tstat already. If that is not the case the resistor should work with Nest. Does not work with ecobee. Ecobee hasn't upgraded the way it works yet.

[@alejandrostaroselski8964]

Hello! I tried to connect the C but as you said, if there are 2 zones or more it won't help.... that was my case ;( My question is, if i want to try the 2 wire (R and W) resistor solution, should i unplug the C wire first or let the C wire inside the hole when plugging the resistor? Many thanks!

[@shielduniversity419]

Disconnect the C wire before you install the resistor

[@alejandrostaroselski8964]

@@shielduniversity419 Thank you very much! One more question, why you said that trying to connect an external 24 Volt Transformer, C Wire Adapter directly to the nest thermostat is not a good idea? (just trying to educate myself because i thought that as an alternative to fix the problem)....

[@TheArtOfConduitBending]

and im asking for a two wire thermostat

[@shielduniversity419]

not sure what you are asking me

[@turbofroggy]

To fix a Nest and a Taco ZVC, all you need to do is connect the C wire. Totally fixes the issue. If your ZVC doesn't have a C connection, use the #1 connection to the zone valve connection for your C wire.

[@shielduniversity419]

I agree. Some old tacos dont have common terminals. Also ive seen some tacos malfunction with too many tstats wired into C. But yes common termiak will solve problem this is just other ways of doing it

[@GucciDiapie]

Do you mean take the wire that is connected to the Zone valve connector (I have 3 wires connected there so not sure which one I would take) and put that into the c slot for thermostat?

[@turbofroggy]

@@GucciDiapie yes. The 3rd wire would be the C wire which provides a constant 24vac. You can get it from the valve side if your zone relay box only has 2 wires for the thermostat. I have 5 Nests on a ZVC 406. Zero issues.

[@Jason-xk1eg]

Hey not sure if you still comment on these, but this seems to be about what I'm looking for, except instead of nest I'm using the newest ecobee (non lite version). I followed all the steps for the relay method, but when using the green wire for C it doesn't seem to have enough power to turn on the ecobee. It just does a quick flicker and then stays dark. Now I do have central air also connected to this unit, would that take more power then for the thermostat? Thanks in advance to any help.

[@shielduniversity419]

Not familiar with the new ecobee. Post pics of your set up

[@Jason-xk1eg]

@@shielduniversity419 it's pretty much the same as ecobee3 and 4 I believe, it might just have Alexa and some new power saving modes. Do you want pictures of the thermostat wiring or taco panel?

[@shielduniversity419]

@@Jason-xk1eg both

[@Jason-xk1eg]

@@shielduniversity419 what's the best way to send pictures. Seems like my imgur link replies keep getting auto deleted.

[@shielduniversity419]

@@Jason-xk1eg [e-mail]

[@BILLIARDLO]

I have a customer with a gas boiler and 4 zones of hot water baseboard heat that are operated with Honeywell V8043E1012 zone valves. They had battery operated thermostats for each zone, then went to 3rd Gen Nests. There are three other things that complicate this: Two thermostats control two separate AC systems in attic. There is an indirect water heater that works off the same boiler with its own zone valve. The original installer installed a Taco Zone Valve controller ZVC-404. I know it doesn't make sense as there really are five zones (four heat and the ID water heater) but somehow it worked where they were "comfortable". Here's the situation: Two heating/cooling tsats work fine, no glitches. The two heating only tsats work for a couple of days then have power error messages. Question: Do I really need the Zone Valve Controller? Can't I just wire the nests with the yellow wires going to the transformer through the nest with the end switches going to the TT on the boiler? Will The Nests work like that? Thank you in advance. Bill

[@shielduniversity419]

I'm pretty sure you can use break one yellow wire, use one side to R and the other to W. and the other yellow goes back to common. You going to need a common wire at thermostat going back to common on transformer

[@BILLIARDLO]

@@shielduniversity419 Thank you. That's what I thought. Is there a way to send you a diagram of my idea of the way it should look?

[@shielduniversity419]

@@BILLIARDLO ok but I can't be responsible if something goes wrong

[@shielduniversity419]

@@BILLIARDLO [e-mail]

[@BILLIARDLO]

@@shielduniversity419 Yes I understand . Thank you

[@beezer5623]

taco sr504 i have this, any advice how to wire the nest to it? Thank you if you can help or direct me to a link.

[@beezer5623]

oh they both have 3 wire

[@shielduniversity419]

@@beezer5623 3 wire very hard to do. Im going to make a video with a new component that may help

[@beezer5623]

@@shielduniversity419 ok cool 😎 thanks man. Happy Turkey Day

[@beezer5623]

@@shielduniversity419 oh one of them I can run a new wire very easy, the other, yikes!!

[@shielduniversity419]

@@beezer5623 yes run 5 wire

[@danielmcdonald5965]

This is a great video. With an SR504 panel, there's no Common for each zone but there's a 24V Common on the left side of the board, separate from the rest. Can you use these same instructions but connecting to that Common instead? Thanks for the help!

[@shielduniversity419]

I will when i gind the old board

[@danielmcdonald5965]

@@shielduniversity419 Unfortunately the separate 24V common didn't work with the RIBU2C. The Nest still reports no power although it can call for heat when needed, it's just not getting power. Any idea if those side 24V common connections actually work?

[@shielduniversity419]

@@danielmcdonald5965 post some pixs of what you did i have no idea what you have

[@danielmcdonald5965]

@@shielduniversity419 Thanks for the quick reply. The board is an SR504-4. Some links to a few pictures are below, there's a lot going on so if something can be shown better please let me know: photos.app.goo.gl/LHfjj479w1z3FkhK6 photos.app.goo.gl/GmVUKZcR5NXoAyCWA photos.app.goo.gl/GmVUKZcR5NXoAyCWA When I measure at the thermostat I'm not getting any voltage. I'm hoping the RIBU2C isn't significantly different from the 1C but the diagrams I saw seemed the same, just for 2 relays so I can control 2 zones. Any tips would be great, please let me know if I can send any additional details.

[@shielduniversity419]

@@danielmcdonald5965 i cannot see anything behind the wires What do you have at the zobe panel TT? Is orange and yellow connected to TT?

[@uggit.804]

Do you guys have any idea how to setup ecobee with edward zone a matic valve?

[@leonelramirez5077]

What is the model number of the valve? Is this existing set up or do you have new equipment and valves?

[@uggit.804]

@@leonelramirez5077 its Edwards MV48665. Connected Rib relay but no response. The valve has no codes. But it has a number on it such as 1, 2, 3, 4, 5, 6 which makes it so confusing. Installing new smart thermostat with existing condo valve.

[@shielduniversity419]

@@uggit.804 I can't find a schematic or the manual for the valve online. Can you post a picture of the terminals and or schematic on here

[@shielduniversity419]

If you can't I will call edwards hydronic and get some info when they are open

[@uggit.804]

@@shielduniversity419 ibb.co/rcgfknB ibb.co/41Q7BW6 ibb.co/8K1kFBC

[@bourret]

Good info. A question --you mention the specifics of the resistor by calling it a 1000 ohm watt resistor. but you didn't indicate the wattage --Is it 1/2 or 1/4 or something else-?

[@shielduniversity419]

Not sure I will find out.

[@bourret]

@@shielduniversity419 Also --my TACO board is an older version model 061699 which I can't find on the internet --my connection points on board to thermostat only show 2 --red and white --no c or common --in this case is there another place to jump the resistor between two contacts?

[@shielduniversity419]

@@bourret can you post a picture ?

[@bourret]

unable to post picture here but i did find one -- go to this link for picture --www.doityourself.com/forum/thermostatic-controls/612022-taco-zvc404-locating-c-question.html

[@timothynorton644]

My new TACO ZVC404 Zone Valve Control includes the resistors (despite their note to buy one) and the manual includes the following note: Troubleshooting: • Problem: Digital thermostats do not work correctly when connected to a zone valve control. • Solution: Some thermostats are a “Power Stealing” type which means they are powered by the zone control with just 2 wires (R & W). A resistor may be needed in order to have the thermostat work properly. This resistor should be placed between the W & C (common) terminals of the zone control. If the thermostat manufacturer does not supply a resistor, a 1000 ohm ½ watt resistor has proven to work with most models and is readily available at electronic supply outlets (e.g. Radio Shack). If the thermostat is battery powered, then check that the batteries are fresh and installed correctly

[@wirewaykingelectric4978]

Your always better off powering the rib relays with a separate 24 volt 40 Va trans as your still robbing power from the taco panels transformer Then simply use the n/o dry contacts and the common from the 40 Va trans back up to the nest t-stat 👍

[@suzanneseale9543]

Why don't you just put the green wire in the C terminal if you have 3 wires? Is the c supposed to be energized? I use the multimeter and it shows no power coming from the C. I can't figure out where the power to the relay is coming from on your video. Is it coming from the Com?

[@shielduniversity419]

You can do that too but I find that when using more than 2 zones it causes issues sometimes. Also not everyone has newer boards with a common terminal. This is also a 2 wire application so in this scenario we dont have 3 wires like you may have. Your suppose to have 24v from R-C if you have newer panel

[@suzanneseale9543]

@@shielduniversity419 I have only 1 common terminal for all 4 zones. But when I put the common wire in there and screw it down, the thermostat reads no power. Have I blown something up or maybe it was never connected correctly? Because I think the comm is supposed to be hot.

[@shielduniversity419]

@@suzanneseale9543 pull the wires off of the common off. If you have 24v after you remove them then im thinking there are too many thermostats and there is not enough VA to power all 4. If there is not power after you pull them off then something shorted and may have killed the transformer

[@garygresge4165]

Why don't you just use the green common wire to the thermostat and for get the relay thing?

[@shielduniversity419]

The reason I made this video is because I found a lot of technician wiring the zone panel with the nest the way you mentioned. Everything works fine as long as the thermostat is not calling for heat. Once a call for heat is made, you no longer have constant power to R and common. You now have one side of 24 volt power going through R and into W. This is where it causes issues with the taco panel, the taco panel randomly clicks on and off, voltage drops, if you have more then two zones, cube relays start to drop in and out. Again this is why I made the video and this is solely based on my own experience. You can call nest or taco for a different explanation

[@shaun8566]

@@shielduniversity419 I am trying to wrap my head around this. If the Nest is charging with the continuous 24v loop provided from R and C, why would it stop charging when there is a call for heat when there is still a continuous loop of 24v but now from R and W? Also does this imply that when there is not a call for heat the circuit is closed using R and C, but when there is a call for heat the circuit is now closed between R and W instead? I believe I am lacking an understanding in how this portion works so I may have not asked properly.

[@shielduniversity419]

It worked well for me. You can even add qn external transformer to make it better. The external being used for tstat circuits. Like I replied to the other guys ok here you can try it your way and if it doesn't work you can do it like the video. The reason I made this was because I has the set up your talking about and it was causing issues.

[@mikeryan7012]

Thank you for this video. Have you tried this 2 wire setup with the Nest Google E thermostat?

[@shielduniversity419]

Not yet I will look into it

[@mikeryan7012]

@@shielduniversity419 I have done the install without the resistors connected to the common because the control board in my Taco relay does not have a C wire terminal. Wired with only the two wires currently, the system appears to be working fine in that all three of my Nest E thermostats are powered up, have good communication with the app, and turn on the heat when I turn the heat up. However, for some reason my zones are not getting up to temp. The baseboard feels very warm, but not hot. I have put a volt meter to the power going to the pumps off the really and they register 120V every time a zone is energized. Any thoughts on what could be causing this? In this instance, could I wire up a transformer that outputs 24V, and solder a 1K resistor to the end of the wire, and then connect that into the W terminal?

[@shielduniversity419]

@@mikeryan7012 i would install a transformer but use relays not the resistor in this case. Also did you turn all the thermostats up at the same time? Does the panel start to make noises and alternate led lights? Are you getting 120v to all the pumps? If you are getting steady 120v to all pumps than you might have a pump issue or air in the baseboard. Did you try purging air ?

[@mikeryan7012]

@@shielduniversity419 Thank you so much for the quick reply. I did not try purging air. However, I have gotten the system up to full temp by simply connecting only one Nest. I have done this to all the zones. Unfortunately it will be very difficult for me to get more than 2 wire run to many of the T-stats which would be necessary to use a rib relay. With the three Nest E T-stats the relay lights do turn red when a zone is energized, and also the boiler "half fires up". The temp at the boiler reads 177. 120V power does read off the relay to the pump for all three pumps when energized. I say the boiler "half fires" because when it is fully running with one T-stat it sounds louder and at a higher pitch than it currently does with all three T-stats connected. It is a HTP high efficiency propane boiler. Sorry if any of this is confusing.

[@shielduniversity419]

If It was my job I would use a separate transformer and use the rib relay method. That way all you are doing is closing tt on taco panel without using up all the voltage by trying to power 3 thermostats and 3 relays and all the leds

[@maddoxinc1642]

NEST thermostats need to have its own transformer for power. They have an internal battery but its not for energizing relays.

[@shielduniversity419]

Hasnt failed me but prob would be better. The be boards have a common not the old board

[@maddoxinc1642]

@@shielduniversity419 I had a lot of problems with mine, had to install 24v transformers to make them work properly as well as isolation relays for the heater.

[@codymartin6704]

My taco controller doesn't have a common terminal 😣

[@shielduniversity419]

So upgrade it to the new model

[@everyuseridtaken]

Mine doesn't either. It does have the 24v COM terminal. I'm not experienced and would rather not have to replace the controller and reconnect all those wires for 4 zones. Can I just run new 18/5 wire for the one zone I need to upgrade the thermostat or is there another solution? I have a heat only system -- 2 wires. Looking to install Honeywell smart tstat.

[@shielduniversity419]

@@everyuseridtaken do you have pic or model number of Taco panel

[@everyuseridtaken]

Yes, it's SR504-4

[@shielduniversity419]

I looked at the panel and there is one yellow wire and 1 red wire coming off of the transformer. I think the yellow is the common. But you would have to cut it and splice it its a lil tough if your not experienced

[@tperki2322]

Appreciate the effort, but you really should organize it better. You call a resistor a diode, then call it a 1000 ohm watt resistor... I am left wondering if I can trust this information.

[@shielduniversity419]

Dont trust it call tech support or read an electrical engineering book

[@joshman2338]

Thanks for this I'm an apprentice electrician we had a job of installing new smart wifi honeywell thermostats and the home owner only had a WHITE and RED to each thermostat that only controlled the heat. We ran the new 18/4 wire and grabbed a 24 VAC common in the ZONE PANEL but did not incorporate the diode. I think the smart thermostat is stealing the power from the zone panel transformer. I shall recommend to try the RIB method because it is safer to the zone panel. I think I did notice the RED LED on the zone panels and it wasn't lit which means it wasn't calling to pull in those relays. Thanks for the breakdown man really appreciate it.

[@josephwalker1204]

Not sure why he is doing this. Please call TACO technical support. They recommend putting your third wire to c at the board and at the thermostat for the zone you are working on.

[@shielduniversity419]

Your not sure because your the type of tech that thinks he knows everything. But yes call taco everyone always call manufacturer

[@josephwalker1204]

@@shielduniversity419 Elderly trying to be helpful. If this is not a viable solution let TACO know. If it is incorporate it into your video. I wish you and everyone that is trying to resolve this issue well.

[@edbuscus360]

This was very not informative. Would have been nice if you explained WHY you can't just hook up a C terminal and WHY you're connecting a whole other relay to a switching relay. "It's not gonna work" isn't the best answer bud. Also hooking up a WHOLE OTHER RELAY to a switching relay is something a hack would do just use the resistor.