TACO Zone Valves For Beginners (wiring, operation, diagnostics)

All of the basics on Taco zone valves (3-wire), from how they work, how they are wired and how to run a few diagnostic tests.
00:00 Introduction
00:24 Terminals #1 & 2
01:02 Internal circuit (terminals 1 & 2)
01:28 Power Circuit (purpose)
01:45 End Switch
01:58 Thermostat's role
02:27 Wiring power to zone valve
03:28 Wiring Common to XFMR
03:39 Testing for power (multimeter)
04:08 Continuity Check on Internal Power Circuit
04:47 End switch / T & T internal wiring (terminals #2 & 3)
05:24 T & T wiring connections terminals 2 & 3
05:45 Operational Timing (Diagnostic Patience)
06:45 Continuity on End Switch terminals
06:55 Multiple Zone Valve Wiring
07:11 Wiring 24V Power to Multiple T-Stats
07:33 Wiring 24V Power From T-Stat to Zone Valves
07:53 Wiring Multiple Commons to XFMR / T Circuit
08:10 Wiring terminals #3 to other T circuit connection
08:30 Different Wiring Configurations Caveat
08:45 Suggested Material / Conclusion

[@WillWinder]

Great video, thank you! A lot of videos have tips and tricks but don't explain what's happening. The way you go into the details, especially about the thermal coil and why the valve takes so long to open, is incredibly helpful. No need to remember tricks now, I know how it works!

[@sweetpeali6313]

Iv been doing hvac for 5 years and had 3 years of schooling and this video is superrrrrr helpful even for me I get confused sometimes! Thank you for the clarity!

[@JerseyMikeHVAC]

Glad it helped!

[@Powernuts]

You’re the man Mike! currently learning to follow my father & grandfather’s footsteps w control wiring, let’s get to that money baby👍

[@supermaple1919]

Good day sir I am so happy I came across your channel because yesterday I had a lot of problems trying to figure out about wiring the zone valves with red and yellow wires. Every channel on KZbin I tried is like a whole PhD course on how to get it done, and I just received all the information that I need from you in just a few minutes you are a master at what you do and you are a great asset to us thank you so much.

[@JerseyMikeHVAC]

You are most welcome

[@pchurch90pc]

Great video boilers are and overlooked area of our field is crazy!!!!

[@dominicpetruzzelli2100]

Thank you. Your video helped me finally grasp wiring and diagnosing these valves. Much appreciated.

[@JerseyMikeHVAC]

No problem.

[@Trapstahjt]

Awesome video man

[@TheMazzimM]

Brilliant.

[@billcameron8119]

Great video exactly what I needed to figure out the wiring in this house thanks!!!

[@JerseyMikeHVAC]

You're welcome!

[@benjamincox8608]

Thank you, great video.

[@JerseyMikeHVAC]

Thank you

[@mikecacioppo5639]

Your good, very informative video. Thank you. 👍👍🌟🌟🌟🌟🌟

[@knightnight1331]

This was very helpful thank you

[@JerseyMikeHVAC]

You're welcome.

[@mikhaelkozik6455]

This helped. I though 3 was 24v once end switch closes so had problem with relay for boiler. This answered problem i had

[@jessicaklein4389]

OMG thank you for this!!!

[@JerseyMikeHVAC]

No problem!!

[@shawnpatriciashalabieh5063]

That was amazing.. good job.

[@JerseyMikeHVAC]

Thank you, Shawn.

[@shawnpatriciashalabieh5063]

Are you gonna make a videos about other zone valve like white Roger. And boiler wiring

[@JerseyMikeHVAC]

I'm going to be doing a boiler wiring video this weekend, from zones valves, aquastat all the way down to roll/spill switches and the gas valve. I'll do a white Roger vid eventually. I like to actually have a few for the making of the video but I don't see them too often.

[@williched]

Thank you

[@JerseyMikeHVAC]

You're welcome

[@holdurhorse9149]

I wish you had explained couple words about the lever on zone valve for manually controlling !!!

[@kennethdengler1763]

One thing when you do a continuity check between terminal 1&2 you got to make sure that the T stat is turned all the way down. So you also won't read through the T stat, and give you a false hope.

[@JerseyMikeHVAC]

Good tip!

[@purenaturefy]

Where is the T stat ?

[@danlux4954]

I have three wires but the zone valve doesn’t turn on the boiler. The pump is always on and the boiler kicks on when aqua stat calls for heat. Trying to troubleshoot one zone to see if it’s the power head or tstat.

[@benhaynie310]

Learning a lot, thanks. Got a clarifying question about my established system, installed late 80s I believe. It's been working fine until recently (I think its a bad valve, gonna keep poking at it). My valves are currently wired with tstat R on terminal 1, 24V xfrm on terminal 2, furnace on terminal 3. I found this vid's wiring and thought it would be better to do it as you have it so that the tstat controls the current on 2 and 3, ideally turning off the furnace when it stops being called. As it is, seems like as long as the valve is open it leaves the boiler running since 2 is getting constant 24V. So if there's a stuck valve (mine is) it ends up constant calling. Is there a reason to have it wired how it is, or would it be better to switch it? Also, it looks like the furnace TnT terminals are both live when being called? One coming off the 24V xfrm and one coming off terminal 3 of the valve. Is that right? I've gotta be missing something, since the system obviously works. Any help would be appreciated!

[@JerseyMikeHVAC]

T stat should not control terminals 2 and 3. Only terminals 1 and 2. A complete circuit between 1 & 2 is controlled by the thermostat which in turn activates the powerhead that will release the end switch and open and close the valve body in the process. The end switch is your control of the furnace circuit on 2 and 3 only. It will not control the valve body if you're trying to bypass 1 & 2 to directly control the TT circuit with the stat. Terminal 2 should only lead back to the transformer common that is shared by both circuits.

[@AlexeyKaplan]

Hi Jersey, in case of combi boiler I am using Utica MAC-150 when should I use external circulator pump? If I do need it can I use only 1 pump for return in case of two zone house (with zone valves)? Is there a way to install circulating pump without control board, using only the boiler TT terminals? Thank you so much for such a helpful videos.

[@rzawistowski33]

Question, I have 2 zones in my house with one of these for each zone, thermostat in bedroom and dining room. Bedroom thermostat and valve work fine. Dining room wasn't working, I figured thermostat cuz its a really old mercury. I changed it, it worked for about a day then nothing. Won't kick on boiler but will click when i pass room temp on the dial. When i check the voltage it was aroud 22. Also, Valve is really hot even when the other "working" valve is cool. My work around was to manually open the valve, basically turning my house into a single zone running off my bedroom, which isn'ta long term solution. It seems 90% likely the valve is the problem. Any thoughts?

[@JerseyMikeHVAC]

What is the VA rating of the transformer and what voltage are you reading off of it? It could be the valve but 22 volts is a little low. Typically I read 26-28 volts off of transformers.

[@gdinunzio136]

Hi Mike, quick question if you have a second to answer. I have an oil burner with three zones; all zone valves are TACO, with a 24v transformer. Two of my zones have Google Nest thermostats (and they work fine). The 3rd zone has an old mercury thermostat. I purchased a Honeywell RTH6500WF WiFi thermostat, and the manual says the device will only work with the C Wire connected. The current thermostat has a red wire to the R terminal and a white wire to the W terminal. A third wire (green) in the wall is not connected to anything, and when I trace it back to the zone valve, the green wire is not connected to anything at the zone valve either. Do I need to use the green wire if 24 v is going to the thermostat via the red wire? I went with the Honeywell because it was cheaper than buying a 3rd Nest. My AC is a separate system from my heat and uses a separate thermostat (A Honeywell connected via a TCC gateway). So I hope if the new Honeywell will work, I can add it to my TCC account.

[@JerseyMikeHVAC]

You can use the green wire as the common. C at thermostat, terminal 2 at zone valve.

[@gdinunzio136]

@@JerseyMikeHVAC thank you. I appreciate you helping me

[@kylemlsantos97]

Awesome video! Why do you prefer a wire nut instead of both wires sharing terminal 2?

[@JerseyMikeHVAC]

Thank you. Only reason is because the connection is more secure with one wire at the screw terminal. With 2 or more wires there, it's possible that vibrations over time can sometimes wiggle one of the wires loose. It's kind of rare, but it's one less potential problem avoided.

[@MrRadiodio]

my Bryant BW1 boiler heat has a honey well controls limit, transformer an relay 3 wires red white an blue going to the taco valves There are 2 valves how do I wire those 3 wires if you dont mind..thank you

[@l.a.m7645]

I've seen a triple aquastat that has a built in transformer labeled T TV Z can u do an in depth video on that?

[@JerseyMikeHVAC]

I go into one of those aquastats in this video here: kzbin.info/www/bejne/m3ObhXagjZpnZ68

[@caflorez89]

I have 3 zone valves. I am having connection issues with zone valve #2 terminal #2 since this has wires 3 wires all tied into it with the screw from terminal #2. The 3 wires are coming from the following. - First wire from zone valve #1 terminal #2. - Second wire from transformer - Third wire from zone valve #3 terminal #2. Can all 3 wires be put in a ring terminal where then the ring terminal is held in place by the screw from zone valve #2 terminal #2 for a better connection? And if yes, do you recommend a specific ring terminal?

[@JerseyMikeHVAC]

Yes. you can do that. Though I would take all 3 wires off of the #2 terminal, snip back and re-strip them, twist them all together with a 4th wire and secure them with a wire nut. Take the 4th wire and put a spade connector on it and secure that back to the #2 terminal.

[@hmdwn]

On my four year old Crown Boiler: the red and white wires going down to my Boiler's TT ... does it matter where the R & W wires connect at the Boiler's TT... I don't see a any markings (+ -) at the T T.

[@JerseyMikeHVAC]

They are interchangeable. Doesn't matter.

[@MiceNine9]

Have a strange diagnostic condition that isn't covered in this video. Maybe somebody can help. The 2 and 3 terminals have continuity on both of my zone valves, even when the valve is closed and there's no call for heat. The valve still opens when the thermostat calls and closes when there's no call, but there's always continuity between the common and the end switch. As a result, my circulator pump runs constantly, even when there's no call for heat. Even tried killing the power to the boiler and unhooked all of the wires, just to make sure it wasn't because of a hack wiring job, but still have continuity. Is this a common failure, or is there something else happening in the boiler?

[@JerseyMikeHVAC]

So you have continuity between 2 and 3 terminals on BOTH zone valves with the power off? Even with the wires disconnected?

[@MiceNine9]

Just wish I had seen this before replacing a perfectly functional relay😕

[@l.a.m7645]

If u don't hear click on tstat and room temp is 62 degrees when setting goes past 62 a click should be heared, if you don't hear that click would tstat be bad?

[@JerseyMikeHVAC]

It depends. Sometimes that could be an indication of a bad stat, but not always. A lot of stats these days have built in delays on them, so even during a call for heating or cooling, there may be a 5-minute delay if the mode was changed from one to the other, if the power was interrupted, if there is a zoning system or if it's just an efficiency feature of a smart stat. Sometimes it's a communication issue between equipment the stat isn't picking up on which can be a set-up/programming issue on new smart stat installs. Typically, if a system isn't doing what its supposed to be doing after giving a stat enough time to work through delays, I'll bypass the thermostat to try to force start the system. If the system starts up, I start suspecting thermostat issues.

[@purenaturefy]

@@JerseyMikeHVAC @l.a.m7645 Where can I find the T Stat

[@purenaturefy]

Where are the #3 (red) wires from both Taco Zone valves going? Where would they connect ?

[@JerseyMikeHVAC]

Those wires get tied into the boiler's burner circuit, which is often power fed through a different step down 24v transformer. They usually run into the boiler itself near the controls and get tied into two T&T wires made available for that purpose.

[@rookie_pulls9676]

where's the final connection for the 3rd wire? I see its connected to the XFMR common (white) and wire#3 (red) all connected but where's the final connection? does go back to the boiler?

[@JerseyMikeHVAC]

I go over all of it late in the video.

[@purenaturefy]

Did you find where the third wire goes?@@JerseyMikeHVAC

[@Arkadiusz.11]

how many zone valves could you put on 1. 24 volt transformer

[@JerseyMikeHVAC]

Typically, a 40va transformer is good for 3 Taco zone valves.

[@jrip4789]

Will a stuck valve cause a circulator pump to constantly run?

[@JerseyMikeHVAC]

Does the boiler cycle on and off with it? Or all alone constantly?

[@carloschavez9425]

The common wire from terminal 3 and another common white wire coming from the transformer there is 2 common wires going to the boiler

[@charlesortega4056]

The transformer red wire and white wire have positive and negative ?

[@JerseyMikeHVAC]

It's alternating current, so no. They can be switched and the circuit can still work. But most transformers will have a "load" and "common" label just to indicate which is the 24 volt source.

[@shanemoro474]

My condo association told me my zone valve was installed backwards and causing "rumbling" idk in the pipes? The maintenance guy took my white wire off terminal 1 and left the red wire on terminal 2. Do I just swap the red and white wires? Was it wired backwards or installed backwards on the pipes? Please help

[@JerseyMikeHVAC]

If it is backwards, it is the valve body that is backwards, not the wiring. Wiring has to go on the same exact way as it was before.

[@yasserovalles2727]

I tried to wire everything the way you shown on the video but I am not getting any power to that thermostat.

[@JerseyMikeHVAC]

My videos cover typical, standard wiring practice, but sometimes HVAC guys get a little creative and do things a little differently. Typically if it doesn't work, this is usually the case.

[@brianr797]

Your the Saggymaster

[@k00lboricua]

So I get 25 volts from my transformer but I get about 1volt from my taco. But they still working. Is there something wrong?

[@JerseyMikeHVAC]

Depends how it's wired, when you're testing and where you're testing at the valve. If it's working, you'll have 24volts on terminal one on a call for heat.

[@danlux4954]

Any propress models ?

[@JerseyMikeHVAC]

Haven't really seen one yet. I'm going to have to get my hands on one soon.

[@Johnnyredtail]

I live in a multiunit sharing the same boiler. My apartment never goes above 68 F degrees no matter how high the thermostat is set for. Is the thermostat being bypassed? I'm thinking the new landlord would like nothing better than to be able to do this.

[@JerseyMikeHVAC]

It's a possibility the way some people are, but there are other issues I can think of first. Are all the baseboards hot or just some? The boiler max water temp limit could have been lowered too. Usually set from 180 to 195. A bypassed thermostat will either not provide heat to the zone at all or will run constantly. A second thermostat could be spliced in somewhere, I suppose, but you'd have to get pretty creative to limit temps to 68 in a remote space using it. You'd most likely have large temperature swings.

[@Johnnyredtail]

@@JerseyMikeHVAC Yeah... I've talked to some of the other tenants and most of the are using extra heaters in their apartments. So it's quite possible the boiler temp is being kept lower now under the new owner. I tried a manual over-ride at the valve unit and it didn't seem to change much. Thanks for the suggestions all the same.

[@mohawkmike142]

you can't check continuity on a zone valve (or any device) with the circuit wires connected.

[@JerseyMikeHVAC]

You can, you just have to make sure the circuit is open at the stat (not calling).

[@cropduster001]

I missed terminal 3. Do I need that for a single zone?

[@JerseyMikeHVAC]

Yes. That completes your T & T circuit so the boiler knows when to fire up and shut down.

[@cropduster001]

You didn't show the terminal 3 hook up. Does it go back to the neutral on the transformer?

[@JerseyMikeHVAC]

I show the complete wiring on all 3 terminals in the later part of the video.

[@cropduster001]

@@JerseyMikeHVAC: I'm in a condo where we share the same boiler. I have two wires from the thermostat and two from the transformer, does that make a difference?

[@JerseyMikeHVAC]

Wire it the same as the others.