Zone Valve Wiring For Beginners (Honeywell demonstration)

Working model of zone valve wiring with motor and end switch internals close up in operation. 4-wire zone valve. How it works and how it is wired into a boiler low voltage system. Full boiler low voltage covered (for beginners).
00:00 Introduction
00:31 Valve Motor 24V Circuit
01:08 T and T 24V Circuit
01:43 End Switch
02:13 Wiring The Motor/Thermostat Circuit
03:54 Wiring The End Switch/Boiler Circuit
04:40 Zone Valve Internals In Action

[@kotaplumbingandheating]

Mike, you’re the man - I always struggled with hydronics/controls when I was starting , wish I had these videos some years ago.

[@JerseyMikeHVAC]

Thanks, David. Me too. My helper has been using these videos to do most of the wiring on his own without me having to step in. Really helps. Thanks for the comment.

[@curtvincent3728]

FINALLY! Someone who shows a diagram with a complete 24 VAC loop! Now things make sense as you talk. The diagram in the beginning is priceless for a newby like me! I took a screenshot of it and printed it out. Thanks Jersey Mike!

[@JerseyMikeHVAC]

Glad it helped!

[@DFWKen]

Thank you, Jersey Mike! That makes something that appears very complex in my home's mechanical into something really simple. We just bought the house and there is nothing here to control an ELAN home control system. So, I'm in the process of removing the 5-zone hydronic system from the ELAN whole house control system and will control it with 5 separate Honeywell T9 thermostats. Immediately, I ran into an issue. First, I simply hooked the two conductors that came from the AprilAire thermostat's R and W terminals to the new Honeywell R and W terminals. No joy! The new thermostat display didn't even light up. Then, disconnecting from the thermostat, I tied together R to W wires and expected it to actuate the zone control valve. It didn't. The 25 vac is present and tying the R and W wires should have, I believe, actuated the valve for water flow and closed the micro switch so that the boiler would turn on. I'm not sure why it doesn't. From my HVAC knowledge and your diagram, I believe it should have. I'll need to investigate further. In the meantime, I reinstalled the old AprilAire thermostat (R and W wires), but I now have to turn on another untouched zone to get the boiler to come on. Your fine video will help me to diagnose further. Thank you for taking the time to make such a good video, simplifying the wiring and how it works. Ken

[@JerseyMikeHVAC]

Those T9 thermostats need a common wire I believe to charge. Thats why it may not be coming on. It's wired correctly, just missing a common.

[@Angel-bs1hm]

At 4:35 am., just wanted to thank you, Jersey Mike!

[@JerseyMikeHVAC]

You're welcome!

[@danielcarrillo4894]

I don’t install boilers often And the one i had today had a mess of wires and looked like crap. After watching this I was able to fix that mess and install all 3 zones accordingly Thank you this saved my day !

[@JerseyMikeHVAC]

You're welcome

[@jimgrass]

You sir, are the MAN! Easiest video to follow out of all of them.

[@JerseyMikeHVAC]

Thank you!

[@richardmore2032]

This was an awesome video. Great job explaining, editing , and no "fluff". More videos should be made like this. Would like to see a video with a "C" wire that the new smart thermostats use.

[@JerseyMikeHVAC]

Yeah getting a lot of questions about that. Planning on doing a vid for that soon.

[@marcelnowakowski945]

Thanks a lot for your videos! Logical, simple, right to the point. Cheers from Vancouver, Canada!

[@Cyprusdoctor]

Mike ,thank you for your thorough explanation.Peter Kariolis.

[@JerseyMikeHVAC]

Anytime, Peter.

[@gurindermanget1848]

Solid Video, thanks.

[@JerseyMikeHVAC]

You're welcome

[@3DRundown]

You, literally, saved my Christmas.... ❤

[@heliodoromadrid8723]

😮 yes finally somebody wants to help the beginners. Thank you again buddy appreciate it so much. Thanks for your knowledge for your time. Thanks for thinking about us the beginners. Have a blessed day man. Hopefully you do more videos man. Thanks, 😅

[@SAMUEL7.3]

thank you very much for that display, very helpful.

[@ahmedtahoum8396]

Thanks Mike for the helpful info. Need more about low water cut off and auto feeder wiring and how they work together. Thanks

[@JerseyMikeHVAC]

Have you watched this one yet? kzbin.info/www/bejne/mITIi6SpbdOSbq8

[@TheJesserdog]

Very easy to understand. Thank you for simplifying it,.

[@JerseyMikeHVAC]

No problem

[@danherring5676]

Nice. That was very clear. Thanks a lot.

[@jaybrown7088]

thanks for sharing, easy to follow.

[@randy783]

Very helpful, thanks. I’m pretty sure I need a new switch

[@mendey14]

Thanks again blessings to you

[@JerseyMikeHVAC]

You are so welcome

[@bilelsalhi4192]

Thank you very much I’m still struggling with this boiler wiring I really appreciate you boss

[@JerseyMikeHVAC]

No problem 👍

[@roncalvo251]

Great video. You make it seem so simple

[@JerseyMikeHVAC]

Thank you

[@roncalvo251]

I have a question..when you add other zones you connect them to together and they all get wired together and get connecter to transformer and boiler wire, correct? Just the thermostat must be added to add zones correct? Thanks

[@JerseyMikeHVAC]

Each zone is a plumbing loop which is controlled by a zone valve, which in turn is controlled by a thermostat. Additional zones would require additional plumbing of some kind.

[@zhang32796]

Awesome mike, thanks for sharing

[@JerseyMikeHVAC]

No problem.

[@genevonderlinden1768]

Great video !

[@JerseyMikeHVAC]

Thank you!

[@escobklyn2696]

Great Job !!!

[@JerseyMikeHVAC]

Thanks!

[@houcineelmerzak3299]

Good job thanks for your help

[@JerseyMikeHVAC]

You're welcome. Thanks for the comment!

[@user-pd4jb7gv7n]

Very cool

[@oilandfireguy1739]

Thank you so much for these videos. I'm an oil burner tech and haven't had any training on the 24v side of things. I work mostly with taco 3 wires tho.

[@JerseyMikeHVAC]

No problem. I may have a few old 3 wire tacos around. I'll put em aside for a future video for ya.

[@oilandfireguy1739]

@@JerseyMikeHVAC thanks so much. I already understand them much better based on these videos!

[@kamrank9846]

You are no 1

[@JerseyMikeHVAC]

Thank you

[@sugarshanemikey7359]

1 year in this video was very helpful. Can you make one where you draw out steam wiring?

[@JerseyMikeHVAC]

Sure. I can do that. Going to be focusing on boiler vids these next few months and and I'd love to get some steamers in there.

[@rcmechanialgroup2856]

Thanks for showing how it works visually. On new installs, is it easier/better do use a zone relays?

[@JerseyMikeHVAC]

No problem. Yeah, if youre running multiple circ pumps then zone relays are the way to go.

[@TedM2024]

Thank you. How would a stat needing a c wire for power tie into this. Example being a tekmar 561 stat.

[@JerseyMikeHVAC]

Typically best to go back to the common on the transformer.

[@ChrisW-vk8ty]

Mike, Love the videos. Learned alot. STRUGGLING with smart stats right now that need C wire. Found electrician had wh and red flipped on power transformer originally and fixed that but still cant get the smart stats to call. Have HW baseboard only, no cooling. Switched wires no issue b4 with old stats. Does the C wire go to the "common" on the transformer or load? Have tried both ways but still can't get it. Have 5 zones total including sidearm dom HW. Thoughts?

[@JerseyMikeHVAC]

I'd you have 5 Honeywell zone valves on a 40 VA transformer it might not be enough power to charge a thermostat on top of it all. Those transformers can only handle 5 zone valves max as it is. How many smart stats are you adding? Have you checked the common wire for continuity to make sure it's good?

[@JR-ly6bx]

wow fantasic demonstration.... basic question on zone valve... do they need to be installed in a specific direction?

[@JerseyMikeHVAC]

Yes. There should be an arrow on the valve body. If the zone valve is going on the supply side of the boiler piping, the arrow points away from the boiler. If on return side piping, arrow should point towards boiler.

[@tahoefor]

Mike, incredible explanation, many thanks. practically everyone else misses the point about dual circuit and little switch behind actuator. Latest boilers like Navien have zone support built in. How does one wire zone valves and thermostats to the boiler then?

[@JerseyMikeHVAC]

I have very rarely zoned out Navian boilers, but what I do know is that the zone relay will have individual R, W and (optional) C connections for each of the zones for the thermostat connections. It will also have Normally Open N/O), Normally Closed (N/C) and Common connections for the corresponding Zone valves. On zone valve connections to the zone controller you'll almost always be using the N/O connection and not the N/C. With Taco 3-wire ZVs, the N/O connection would go to terminal #1 and the Common to terminal #2. On Honeywell 4-wire ZVs, One wire would go from N/O to one of the yellow wires and the Common to the other yellow wire. Doesn't really matter which way. I have seen Taco zone valves wired into Navian zone controllers without terminal #3 on the ZV being hooked up at all, so although I'm fairly certain, I'm not 100% sure that Navian PCB Zone control doesn't require a TT signal from the Zone valves end switches. The ZVs only need power to actuate the physical valve itself. So I'm assuming it's the same with Honeywell 4-wires in that the 2 red wires are not hooked up. I believe the only time T/T wiring needs to be made is when you're running more than 3 zones and an external zone controller is required, and that would be from the external controller to the internal zoning panel in the PCB. I have also been made aware before that the PCB setting have to be set to "zoning disabled" for it to work, which seems completely counter-intuitive to me, but it seems enabling that feature is for when you're using Ready-Link cable for the external Navien Smartzone Zone Pump Controller, rather than for when you're zoning directly off of the PCB itself internally. You likely need an external circulator pump for Navian zoning applications, as the internal pump is often not sufficient.

[@tahoefor]

​@@JerseyMikeHVAC thank you for reply. you gave me very valuable hint and hopefully useful to your other subscribers. I troubleshot my wiring, called support line, I have the same Taco zone valve, normally closed as you've shown in the video. Latest NCB boilers do not need the 2nd red cable pair, the little switch at all. I left those wires hanging. I hooked up my yellow cables actuator to normally open (NO) and common on the boiler. This has to be a mistake in vendor specification because my valve is normally closed (NC). When tstat calls for heat, NO pair of connectors is energized to ~26 VAC and stays at 26V until the valve is open, letting the water through into the coils. The normally closed pair is at ~2V. Traditional 24V wall transformer can be removed. External system pump for radiant heat is also driven by thermostat closing R->W bridge on the boiler. 120 VAC pins are on boiler front panel. It's sufficient for smaller pump under 2.5A max. My pump will stay on until desired supply temp is reached plus few degrees over. It then turns itself off until supply falls 10F below desired T to prevent short cycling. Since the boiler is the one providing the power for zone actuators, it feels like there is no ambiguity or the need for the switch loop anymore. It knows whether it's sending 24V to the motor or not. Valves and pump are working perfectly and synced with thermostats. I am off to new problem. plumber got something wrong and the water is not going into floor supply, pressure dropped.

[@JerseyMikeHVAC]

@@tahoefor So it WAS N/C. Makes more sense. I was thinking N/O didn't sound right, but I was told N/O.

[@georgek.6494]

Hey. great video ! I do have a question about radiant flooring.. I had 3 zone valves.. I replaced 1 zone with radiant heating. Do you have a video explaining the wiring from the thermostat?

[@JerseyMikeHVAC]

Not really familiar with radiant floor stats, unfortunately. But I can't imagine them working radically different from conventional thermostats.

[@patrickmaloney4125]

Mike - great video, even better was your explanation. I am in the process of modifying a 5 zone boiler system and incorporating the a/c into the mix. What is your recommendations with the smart thermostats & controllers available. My goal is make the system work from one thermostat, including the a/c. Luckily, the builder installed 5 conductor wiring for each of the 5 thermostats in the house. Right now everything is operated manually with the old mercury thermostats. Thanks!

[@JerseyMikeHVAC]

Is your AC system Zoned? or is it just 1 central thermostat?

[@patrickmaloney4125]

@@JerseyMikeHVAC a/c system is one zone, ductwork throughout entire house.

[@patrickmaloney4125]

@@JerseyMikeHVAC one thermostat for a/c

[@JerseyMikeHVAC]

OK. Another question (sorry), but when you say you want to make it all work from one thermostat, do you mean all 5 zones from one thermostat? Just want to be clear before I give advice. I also need to know what kind of zone valves you have.

[@patrickmaloney4125]

@@JerseyMikeHVAC So I thought that was a good idea, and I am seeing that perhaps it's not. I thought controlling everything from one location would be efficient and more cost effective by keeping teenagers from manipulating the thermostat to frequently. Since I first sent this question, I learned that one of the zones can control the others, and that is the case here for one of the other zones. I will get back here once I troubleshoot these zones. By the way, the wiring is a spaghetti mess. I am considering using Nest 3rd gen thermostat(s) for each zone, however, I would like the main floor thermostat to be both heating and cooling.

[@buildingnfixing7348]

Thank you for the great demo. I am having issues since I started cleaning up my boiler and installing Nest thermostats. Any chance ya can hit me up if ya have a contact?

[@fuelsmalden]

Could you make a video explaining wiring an external zone control on an oil fired boiler. Controlling donestic hot water?

[@JerseyMikeHVAC]

It's the same set up. Only difference is than an aquastat on the water storage tank takes the place of the thermostat. When the water temp drops below the setting on the aquastat a switch closes and the zone valve motor is energized the same way a thermostat energizes the zone valve motor on a call for heat.

[@shytown2406]

Mike I have steam radiators in my house, single pipe, do I need to bleed the radiators of air even though they are steam?. I have some radiators that get hot very quickly and some take forever to get hot. Love your channel.

[@JerseyMikeHVAC]

Usually there is either a steam trap or an air vent on the radiator that is hindering things. If the radiators that take time to heat up are hot in one spot and cooler elsewhere there may be water trapped in there. Sometimes the little air vent is plugged. One little trick you can try is to remove the air vent and try to vacuum out the radiator through that hole. Sometimes that frees things up for me.

[@Woaitudou]

Mike, thank you for the great video. I have the same 3 zone wiring just like you are showing here. Now I understand how the spaghetti works. I have a question for you. I am going to replace the thermostats with the Google Nest thermostats. The instruction says it needs a C-wire, but I only have two wires connecting to the existing thermostats. How do I solve the problem? Do I have to use a power connector? If yes, how do I connect it? Thanks.

[@JerseyMikeHVAC]

I just released a video a few hours ago on how to wire a power connector to a taco zone valve, but if you're going to install multiple Nests it probably isn't going to work. You may need an external transformer and relays. Im going to be working on a video for that.

[@Woaitudou]

@@JerseyMikeHVAC I watched your video about connecting the power connector to the Taco valve, which is different from the Honeywell valve. How to connect to the Honeywell valve as shown in this video? Thanks.

[@JerseyMikeHVAC]

@@Woaitudou I did a similar video on the Honeywell valves. You can check it out here: kzbin.info/www/bejne/jofWYZ5nlsatl5Y

[@jdavey4138]

Mike, Where is the C-wire required for Nest thermostats? My wiring has 4 wires, but only red/white are hooked up.

[@JerseyMikeHVAC]

The common is on the 24v side of the transformer. One terminal will feed 24v to the tstat/zone valve, the other receives it back as the common.

[@leibynunez675]

Can nest thermostat and an old thermostat control their own zone? How would that wiring look like?

[@JerseyMikeHVAC]

Sure. Wiring is the same, aside from a common wire that may be required for the Nest. I have several videos on that.

[@soufianemess7681]

Hi. Thanks for the video! I do have a quick question... I just finished installing a smart thermostat for my boiler and I connected the thermostat with the R (load) rather than at the end with C. Is there a good practice on that? In your diagram we can see the C from the transformer goes to W of the T-stat. Mine would go to the C of the motor. What's your thoughts?

[@JerseyMikeHVAC]

That's perfectly fine. It's a simple circuit and you can go either way with it.

[@soufianemess7681]

@@JerseyMikeHVAC I was thinking the same.. except when your t-stat is having R from the transformer connected to it.. you either need to shut off the electricity completely before manipulating a t-stat or be careful with the wires (R) when pulling off the t-stat. I feel like you gonna tell me the best practice is anyway to shut off completely electricity before doing any work :D thanks for the reply

[@JerseyMikeHVAC]

@@soufianemess7681 Ha. Yeah pretty much, bit just to protect the transformer from burning out on a short. No fuse in the circuit.

[@bnappi22]

I have 3 zone valves with low voltage but 1 is 120v to an old thermostat. Can you explain this? How can I convert this last thermostat to low voltage? ty

[@JerseyMikeHVAC]

How long ago was the boiler installed? Generally a line voltage thermostat wires directly into a heater, like an electric baseboard heater. If there was an electric heater or some other line voltage heating arrangement existing before the boiler was installed, it's possible a 120V zone valve and thermostat was worked into the newer heating system running on low voltage controls as a lower cost alternative, because it would have been a difficult and costly job to run new low voltage wiring between the boiler and location of the 120V tstat. In other words, they stuck with the 120V arrangement because it wasn't worth the cost t convert to low voltage. I have encountered a few situations where running new low voltage wiring to an existing tstat location wasn't possible without a lot of tearing into walls. We resorted to installing a wireless tstat with a receiver running the zone valve.

[@hmdwn]

Mike, I'm in SE Pa. (19036) you need to come over!

[@JerseyMikeHVAC]

Maybe I will!

[@hmdwn]

@@JerseyMikeHVAC ... please let me know if you service SE Pa. my newish Crown Boiler is frying zone valves $$$$$. Unless new old stock green tops Tacos have an expiration date (joking) And now it's tossing a code 4 error. Heck it's only three years old!

[@JerseyMikeHVAC]

@@hmdwn Ha. Nope. Definitely not your Tacos. Unfortunately, that's a little bit of a hike for me (I'm just outside of NYC). But code 4 is a no flame signal. Shut off the burner switch, clean the flame sensor in there with a dollar bill (it's down by the burners) and turn it back on. That might be all it is. If not, it may be an issue with the wiring or control board itself. Crown used to be a really good brand, but it's taken a real nosedive lately.

[@user-oc1ei9jk2j]

Hi, In our area they use these Honeywell V8043F1036 3/4" Sweat Zone Valve with Screw Terminals and End Switch. Can you do a video with one that has the screw terminals? Please, please, please.

[@user-oc1ei9jk2j]

also the setup on my boiler is daisy chained. I would love to see how the first valve is wired.

[@nilolee2426]

Hey Mike, new subscriber here. I have a question regarding my original gas boiler hydronic system installed in early 90s. It doesn’t have spill ,rollouts switch in Utica boiler. Everyday I watched KZbin, I learned about safety issue from you guys. Thank you. Do I need to install these safety switches now?

[@JerseyMikeHVAC]

Yes I think you should, but you want to call the manufacturer directly and get their recommendations on what switches specifically to put in. You can't just use any switch. I'm sure you won't be the first to call about it, so they should have answers for you.

[@nilolee2426]

@@JerseyMikeHVAC sorry to bother you again ,I called the company today and gave the model of my boiler, she said Utica aq02101 for both spill and roll out switch but when I look it up it’s look the picture is more looks like for spill switch only. I’m not sure if she’s right about the roll out. Can I just put any roll out switch (the one that has like a thermistor)?

[@nebulousJames12345]

on the zone valve, does it matter which red or yellow wire is connected to which? or can it be either red and yellow wire?

[@JerseyMikeHVAC]

No they can go either way, so long as red and yellow are not mixed. Those are separate circuits.

[@nickortega46]

Can you do a video on the uponor zone valves or is it the same thing

[@JerseyMikeHVAC]

I haven't worked much with Uponor, but I looked at Uponor's manuals and diagrams and it's exactly the same thing with their 4-wire valves.

[@kyledakilla8724]

I've installed these at work and only have to use the 2 yellow wires and not use the red wires. Why is that? Thank you, great video!

[@JerseyMikeHVAC]

The red wires are a separate circuit with these zone valves, often powered by a completely different transformer. They're no connected to the thermostat at all, but the boilers burner circuit directly. The zone valve acts like a relay between one circuit off of the yellow wires and the thermostat and the other circuit on the red wires and burners.

[@missdhara6434]

Can someone please help? I installed a new gas bolier recently. But for some reason the boiler is running without reading the thermostat. Is this a faulty wiring or something to do with the boiler installation? The thermostat is getting power, it reads the time and measures the temperature in the room, but it doesnt regulate the house temperature set on the thermostat with the boiler . Its set at 70 but the house temp is 90! Is this a wire burnt out or is it a faulty installation? its Burnham X207, 210,000 BTU gas fired hot water boiler. How could the thermostat just stop working all of a sudden when it worked just fine before the boiler was installed? Seems to me the wiring to the boiler just wasnt done right.

[@NROhvac]

Do you live in PA/Jersey area? Are you still having trouble?

[@pgreenx]

1:52. I thought the zone valve button turns on the pump and not the boiler? Doesn’t the boiler fire independently to maintain temp?

[@JerseyMikeHVAC]

A Triple Aquastat will fire a boiler independently to maintain a minimum temp. On a cold start boiler arrangement, the end switch fires up the boiler and a circ pump together.

[@pgreenx]

@@JerseyMikeHVAC thanks - I had to replace me zone valve and it looks like it supplied power to the pump relay or something like that

[@ginbimbe3150]

Forgive me. I’m trying to understand this. It’s been a few years since I’ve been in the field. But if a goes to common isn’t that hot to common. A direct short ? I thought tstat terminals are breaking hot ?

[@JerseyMikeHVAC]

It's not going directly from hot to common. T stat gets power at R through the zone valve motor wiring. W goes back to common. Some guys put the ZV on the W wire side and just run power straight to the stat, but ZV motor doesn't run either way until the Tstat closes the circuit.

[@ginbimbe3150]

@@JerseyMikeHVAC ok yeah I was just talking with someone and I think I get it. Or at least what someone was explaining to me earlier. .. r from transformer up to r at stat. Out w to one yellow on zone valve. Same for next tstats and zone valves. Other yellows are in common. Can get wire nutted. One red wire from end switch goes to “t” terminal at boiler. And other red to other “t” terminal at boiler .. am I on point or way off? Lol. Appreciate your assistance sir.

[@andreaskallika3993]

How do i add a c wire to a nest in this circuit

[@JerseyMikeHVAC]

Common at the transformer

[@corbana4743]

Mike awesome videos, I could use ur help wiring my new peerless boiler, two zone valves plus I got to add another zone valve to the indirect water heater, willing to pay if u help me remotely. I can do all the plumbing no problems just wanna make sure my wirings right Thanks

[@JerseyMikeHVAC]

The aquastat for the water heater can get wired into the zone valve like a thermostat. Only difference is that it doesn't matter which way red and white get hooked up, so it's easier. I have a few other zone valve videos that might help you out. Let me know if you have any questions

[@stephenboyd4775]

You have a dead short from r to common in your diagram

[@JerseyMikeHVAC]

There isn't. I just didn't include loads existing in the burner circuit to explain zone valve operation. The load items are represented by the single lightbulb in the video.

[@kevonslims7269]

That’s an odd way to wire then system. All reds from thermostats should go to hot from external transformer All w form thermostats should to one side of zone motors The common from external transformer should got to other side of zone motors Then the TT should be wired in parallel to all 3 zone end switches.

[@JerseyMikeHVAC]

A guy who did this for 25 years taught me this way, but I have another video showing the same way you describe it as well.

[@Mobileunit6]

Still confused

[@cropduster001]

Maybe for beginners you should start with one zone.

[@JerseyMikeHVAC]

I did start with wiring in just one valve. I go into wiring multiple valves in another video.

[@cropduster001]

@@JerseyMikeHVAC: I have a 555-050 3 pole and can't find a simple wiring diagram. I don't know how to test the power head.

[@JerseyMikeHVAC]

kzbin.info/www/bejne/oZ-aZIlmd9OGp5Y

[@tenzinlhawang9792]

Thanks, it helped a lot 🫡