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Honeywell heating zone valve Heating Zone Valve Wiring & Manuals
Index to Zone Control Manuals & Diagrams - wire up a heating zone valve

Hot water heating system zone valve installation manuals. Here is our index to zone valve manuals, sorted alphabetically by manufacturer name.

We include basic zone valve wiring instructions. For detailed zone valve wiring, choose the manufacturer from our list and then the instruction manual for your specific zone valve.

This article series describes how to wire up heating zone valves.  We include wiring diagrams and installation instructions for most zone valve model and multi-zone controllers, and we describe special wiring problems that can occur if you mix different types, brands, or models of heating zone valves on the same hydronic heating (hot water heating) system.

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

Zone Valve Wiring Hookups for Hydronic (Hot Water) Heating Systems

Taci ZVC493 wiring diagram - click to enlarge - at InspectApedia.comZone Valve Manuals & Wiring Diagrams - Alphabetical

Individual Hydronic Heating Zone Valve & Control Wiring Notes by Brand are given below.

Also see

COMPATABILITY ISSUES AMONG ZONE VALVE BRANDS / MODELS - wiring conflicts & confusion

Illustration: the wiring diagram for the Taco ZVC 403 Multiple-Zone-Valve Controller. [Click to enlarge any image] - be sure to check the exact wiring diagram for your particular control and application.

Caleffi Z One Zone Valve Installation & troubleshooting at InspectApedia.com ... Caleffi Z One Zone Valve Installation & troubleshooting at InspectApedia.com

 

How to Wire Multiple Taco SR502-SR506 Switching Relays

How to wire two Taco switching relays in series to control up to 8 heating zones - at InspectApedia.com

To control up to eight heating zones you might wire multiple standard switching relays together as shown in this TACO wiring diagram. This illustration is from the TACO SR503-4 Switching Relay Instruction Sheet whose link is given above. [Click to enlarge any image]

Watch out: Be sure to see important instructions and safety notes in that document.

Question: Having trouble wiring up different zone valve controller brands together

Mixed brand zone valve wiring schematic (C) Daniel FriedmanHi, I have a HE II Weill McClain natural gas boiler.

A few years back I converted about 1/4-1/3 or my house into hydronic radiant floor heat running off same zone as the baseboard. The guy who sweated the tubes and zoned it out has never come back to hook up the zone controller.

Schematic at above-left: wiring hookups for a mixed-brand zone valve installation: Honeywell & White Rogers. Click to enlarge any image or schematic.

Someone else came out the other day to hook it up. I have a TACO SR502 2-zone controller and this person purchased a Honeywell L6006C 1018 aquastat controller.

I am thinking he purchased the wrong aqua stat.

He said the whole system will never allow for 2 zones. [Click to enlarge any image]

I spoke w/techs @both TACO and WeilMcClain who, both said, I can have my floor heat operate separately from the BB units.

(I do have 2 thermostats).

Can you shed a little light on this, please? Thanks, - T.B. 10/27/2013

Reply: known problem; Example of Wiring Different Brands of Zone Control in Same System

Absolutely, if properly wired, you can take a single loop of hot water baseboard heat and subdivide it, giving each sub-loop its own thermostat and zone control valve.

Properly wired, the individual thermostat calls for heat, the zone valve opens, when the valve is fully open an end switch in the valve connects a second pair of wires that turn on the circulator pump back at the boiler.

Photo below, (reader contributed) illustrates typical wiring connection at two zone valves.

Zone valve wiring, multiple zones (C) InspectApedia On most U.S. systems the circulator runs sending water through the open zone loops and a primary control at the boiler, monitoring water temperature, actually turns the boiler on or off as needed to re-heat the water.

In addition to your control, the Honeywell L6006C 1010, Honeywell's L8124A,C and 8151A are triple aquastats similar in function, often used to control zone valves.

Where you can run into trouble is with an installation that has a mix of different brands of zone valves. In that case, the wiring instructions for one company may be different from the other.

When I got into that trouble years ago I was wiring up a Honeywell zone valve to a system already using Flair zone valves. I called my heating supplier who had Dave Ferris (now retired) on deck to answer wiring questions.

The solution was trivial once Dave said - Just hook the red wire to terminal "x" and the yellow to "y" and so on.

My ugly rough sketch above on this space needs to be re-drawn neatly, but there I show how we successfully wired-up a mixed brand zone valve installation. I had two Honeywell zone valves and one White Rogers zone valve. [Click to enlarge any image].

Watch out: in wiring the mixed-brand zone valves shown in my sketch above, it is important that

The correct wiring depends on the zone valve models.

Without Dave the next-best is to look  with care at the instructions that came with the zone valves, and at the wiring diagrams for hook-up instructions; if you are left still confused, the manufacturer will know how to hook-up.

More about wiring Taco zone valves -

see TACO ZONE SENTRY VALVES [PDF] installation instructions

Zone Valve Compatibility Notes

Typical zone valve installation at a heating baseboard - Flair Corporation adapted by InspectApedia The Flair and White Rogers are compatible with one another with no special tricks

Watch out:

The Honeywell zone valves are NOT compatible with Flair and White Rogers unless you follow careful wiring details.

I give an example above, but you may need to review wiring with the manufacturers of your zone valves.

In fact Zone-A-Trol zone valve installation instructions carried this warning:

Zone-A-Trol Valves should not be wired in the same circuit with zone valves of a different make or manufacturer

without first consulting your local Zone-A-Trol representative or our factory engineering department for special wiring information. [2]

Master Control & Zone Valve & Thermostat Wiring Connection Tips

The thermostat wires on the master (primary) control will show about 20-volts from the on-board thermostat relay transformer inside the primary control.

No voltage should be presented by the zone valves, thermostat, or transformer circuit TO the primary Controller.

We see 24-volts through the zone controllers and transformer but Zero voltage on the zone valve end switch wires that go to the thermostat TT terminals on the master or primary control.

Reader Question: how many zone valves can be connected to a single thermostat?

3/5/2014 TEJ said: how many zonal valves for floor heating can be connected to one room thermostat

This question originally was posted

at ZONE VALVES, HEATING

Reply: use of a switching relay to control multiple devices from a single thermostat

Normally one thermostat controls one heating zone and is connected to one zone valve. But as the thermostat is basically an on-off switch, indeed we've discussed with readers the successful combining of more than one zone valve switched by the same thermostat.

Watch out: to avoid overloading the TT or its power or circuit, check the zone valve wiring instructions. For switching multiple zone valves with one thermostat you may need to have the thermostat control a switching relay that in turn switches the gang of multiple zones.

A typical switching relay such as the Taco SR502 - 506 can swit3ch 4 zone valves or more.

To find out more about the Taco switching relays I cited contact

or if you are in Canada contact

The company's website is at www.taco-hvac.com and their wiring guide is at www.taco-hvac.com/uploads/FileLibrary/100-9.0.pdf

Danfoss Zone Valve Controls, Manuals, Instructions

Other Danfoss manuals & products are at

Honeywell Zone Valve Wiring Wire Colors

General Honeywell Zone Valve Wiring instructions (just below) are followed by links to Honeywell Zone Valve Instruction Sheets

Typical zone valve yellow & red wire connections:

Honeywell zone valve wire sketch (C) Daniel Friedman

[Click to enlarge any image]

Honeywell zone valve wire sketch (C) Daniel Friedman

See this image for DETAILED WIRING DIAGRAMS FOR HONEYWELL ZONE VALVES V8043A, V8043E, V8043F & T822

See this image for DETAILED WIRING DIAGRAMS FOR HONEYWELL ZONE VALVES V8043E & T822 & T822

See this image for DETAILED WIRING DIAGRAM FOR A TYPICAL 3-ZONE - HONEYWELL ZONE VALVES & AT87A TRANSFORMER

See this image for DETAILED WIRING DIAGRAM FOR A TYPICAL 5-ZONE - HONEYWELL ZONE VALVES & AT87A TRANSFORMER

Above Honeywell zone valve wiring diagrams are from Honeywell's motorized [zone] valve installation instructions [3]

Watch out: when installing zone valves not to overheat the valve or its parts.

Honeywell MZV Zone Valve actuator cited & discussed at InspectApedia.comWe were taught to completely remove the zone valve motor and electrical parts while sweating the zone valve to the heating system piping, but even so, overheating can damage the zone valve moving parts or o-ring seals.

Honeywell warns not to use silver solder when sweating zone valves because of the higher temperatures required with silver solder.

Honeywell Zone Valve Installation & Wiring Manuals

Shown here: Honeywell MZ Zone Valve Actuator motor

Flair Zone Valve Wiring Connections at the Thermostat & at the Zone Valve

From Flair Manufacturing's original installation instructions for the Flair Zone-A-Trol we include these wiring details. The Flair Zone-A-Trol valves in the company's wiring diagrams are typically shown wired in parallel.

How Are Multiple Zone Valves Wired?

On installations where it is not convenient to wire from valve to valve as in the diagram, a separate 3-color wire conductor can be run from terminals 1, 2, 3 of each zone valve to a convenient junction point.

By observing and respecting the color codes, conductors from corresponding-numbered terminals of each zone valve may be joined or spliced together and a single conductor may be conducted from that splice to the appropriate power and control terminals shown in the wiring diagram.

Wiring the Zone Valve:

Wiring the Thermostat with this zone valve

Watch out: when connecting wires to terminals at the zone valve and at the thermostat or any other control, do not let the stripped end of the wire touch or short out against any other wire or terminal.

Flair zone valve hookup schematic (C) Daniel Friedman

Multiple zone valve wiring

Below we illustrate how a "gang" of Flair zone control valves would be wired-up.

Flair zone valve hookup schematic (C) Daniel Friedman

Flair zone valve hookup schematic (C) Daniel Friedman

See this image for Complete and detailed wiring diagrams for FLAIR 2-WIRE ZONE-A-TROL VALVES. [image] An example from that page is shown just below.

See this image for Complete and detailed wiring diagrams for FLAIR 3-WIRE ZONE-A-TROL VALVES [image]

Flair zone valve wiring for 2-wire thermostats

Flair Zone Valve with 2-Wire Thermostat: wiring diagram

The Flair control wiring diagrams below are excerpted from THERMOSTAT WIRING DIAGRAMS

Flair 2-wire thermosat wiring diagram at left the thermostat wiring diagram illustrates use of a Flair APOV2 wall thermostat in a typical 2-wire application controlling a heating appliance.

In this application the thermostat is acting as an SPST (single pole single throw) switch to turn heat on or off, often by operating a zone valve.

When used to operate a zone valve the thermostat wires are connected to the zone valve terminals, not to a primary control on the heating boiler.

[Click any image to see an enlarged, detailed version]


Flair 3-wire thermostat wiring controlling a zone valve

Flair Zone Valve with 3-wire thermostat: wiring diagram

At left the thermostat wiring diagram illustrates typical use of a Flair APOV2 wall thermostat in a 3-wire application controlling a heating appliance.

In this application the thermostat is acting as a single pole double throw (SPDT) switch to control heating & cooling or in some zone valve applications.

Also see our table of Flair thermostat wiring connections found above at

The table below is an excerpt from THERMOSTAT WIRE CONNECTIONS

How to Wire a typical Flair 3-wire type Wall Thermostat

(3 wires found in use at the wall thermostat)

Flair model ANOVO Thermostat fed from a Flair zone valve

(4)
As wire colors may vary, note the wire colors Wire coming from Flair zone valve terminal (4) "Open" . Note 1.
(5)
At the Flair zone valve and Wire coming from Flair zone valve terminal (5) "Common"
(6)
Match those colors to terminals at the thermostat as shown here Wire coming from Flair zone valve terminal (6) "Closed"

Notes to the Table Above

1. The [Honeywell 5-2 Day Programmable Thermostat - RTH2300B1012] thermostat cannot be used if your old thermostat had and used any two of the following wires: R, RC, RH, 4 and V.[5]

More Flair Zone Valve Wiring Instructions Diagrams

Macon Controls Zone Valves, Manuals, Instructions

Macon VM-Series Electric Zone Valve Actuator at InspectApedia.com

Macon Z60000 Electric Zone Valve Actuator at InspectAapedia.com

Schneider Electric Zone Valve Manuals

Reader Comments & Q&A on Schneider Zone Valves

On 2020-02-25 - by (mod) - troubleshooting Schneider Zone Valves

Leo

I'm puzzled too but your diagnostic steps so far are helpful; clearly something is dropping power - either just to the thermostat or to the thermostat and to the boiler itself or to a circulator or circulator relay.

The cause of power drop could be deliberate: a timer or economizer, or a poor connection or control board (perhaps affected by temperature variations).

Forcing the zone valve open and then getting heat tells me that the circulator was running but the zone valve not opening.

That condition means that hot water can't circulate from the boiler through the zone and that in turn would mean the boiler is seeing the call for heat, turning on, heating up but then reaching its HI LIMIT and shutting off.

So I'd look for a sticking zone valve or bad zone valve control head.

On 2020-02-24 by Leo

Hi, I am having an issue with my heat that and I cannot diagnose what could be the source of the problem. I have 2 zones(2 normally closed Schneider zone valves) water boiler and 2 AHU(basement and attic).

Zone 2 heat works perfectly fine during the day, I checked the Rh and W1 wires with voltmeter, get 28V reading. When I use ecobee app standing next to the water heater and call for heat I see the zone valve opening and hot water starting to circulate. Works just as it should.

Something that I cannot explain happens at 10PM, The Rh and W1 wires reading is 0, when I call for heat the zone valve does not respond. I changed the zone valve and ecobee, did not help, exactly the same issue.

In the morning at about 9AM the power to Rh and W1 are back on and everything works fine. When during a night I use the manual ON lever on the valve the boiler kicks in and works just fine. What do you think could be issue and how could I fix it? Thank you!

 




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Reader Comments, Questions & Answers About The Article Above

Below you will find questions and answers previously posted on this page at its page bottom reader comment box.

Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2020-10-20 - by (mod) - how do I add another 24V transformer?

Spark

You'd use an additional transformer to send 24VAC right to the zone valve that's in turn switched by the thermostat

See examples on the page above or in this example from the page:

Example of transformer power to zone valve (C) InspectApedia.com

On 2020-10-19 by Sparky

My boiler is working but isn’t the aquastat L8148A transformer to small to power four zone valves and i need to add another transformer? If so how do i wire it?

How to wire a separate transformer to my four white rogers type 1311-102 units and my Honeywell aquastat L8148A,E,J

On 2020-05-24 - by (mod) - how do I wire up my zone valves?

Eddy

Please start with the zone valve wiring described on the page above. Then don't hesitate to ask if any of that is unclear.

In the most general terms, of 4 wires at a zone valve

2 wires are connecting to the thermostat to get a call for heat - the thermostat activates the zone motor that rotates to open the valve.

2 wires connect to the circulator pump or boiler to tell it to run - that's an "end switch" that closes to turn on the circulator after the zone motor has rotated to open the zone valve.

On 2020-05-24 by Eddy

From the boiler there are 2 wires that connects to the thermostat how do i add a zone valve with 4 wires to the system?

On 2020-04-22 - by (mod) -

Sure, Steven,

Take a look at our wire size guide over at SE CABLE & BRANCH CIRCUIT WIRE SIZES vs AMPS

and you'll see three sizes of thermostat wire often used, #20, #18, and #16, but the most common is #18 wire.

In fact,

Honeywell ProSeries thermostat wiring connections (C) Daniel Friedman at InspectApedia.comWatch out: recently, repairing a no-heat problem at a home in northern Minnesota we found that a service tech had installed a new Honeywell ProSeries programmable thermostat that was giving trouble: intermittently the thermostat just wouldn't call for heat - it would not switch on the zone circulator.

I finally tried wiggling and tugging on the thermostat wires originally wired thoughout this home in about 1960. The Honeywell thermostat uses a "push-in" thermostat wire connector and it just was not grabbing the wires reliably.

I replaced the fancy (expensive) programmable ProSeries thermostat with an older-style and very simple Honeywell T87 thermostat that uses an actual screw terminal to grab the thermostat wire.

I'm happy to report that better thermostat wire ended the recurrent no-heat problem in the home.

Taking a closer look at the old copper thermostat wire that was, after more than half a century of service, still in great shape, I noted that it was #20 wire - a bit smaller than what some modern controls anticipate, especially the push-in-connector types.

Thus I prefer #18 thermostat wire in new installations.

Below is the Honeywell ProSeries thermostat, removed from the wall, showing those push-in wiring connections.

On 2020-04-21 by steven k

hi, i'm adding a 3rd zone, heat only.
my hot water boiler is piped for it and has a vacancy,,, and my TACO box also has a 3rd zone opening.

My question is hopefully a simple one... what gauge wire do I need to run to the new thermostat??
thanks

On 2020-03-08 - by (mod) - help wiring a Valemo zone valve

Sure Bob

Take a look at the Valemo zone valve installation manual that includes wiring diagrams (like the example I give below) found at

VALEMO ZONE VALVE IO MANUAL [PDF] (2016)

Valemo zone valve wiring connections cited & discussed at Inspectapedia.com

On 2020-03-08 by bobblkship

Need wiring diagram for Valemo zone valve with two black wires for thermostat control and two red wires for end switch.

On 2019-11-09 - by (mod) - simple diagnosis to see why your zone won't shut off:

Tyler:

Let's do some simple diagnosis to see why your zone won't shut off:

Basically the room thermostat is nothing but an on-off switch responding to room temp.

Go to the thermostat for the heating zone that won't shut off.

Disconnect the thermostat from its wires - leave the two ends apart.

DOES THE ZONE VALVE CLOSE - or if you don't have zone valves - DOES THE ZONE CIRCULATOR STOP?

IF the zone STOPS then the problem is the thermostat itself or a setting on it

If the zone does NOT STOP
Then
It is possible that the thermostat wires are shorted together.

We'll check that next.

Simple test for shorted thermostat wires:

How to test the TT wires for a short together.

Disconnect the thermostat from the wires at the wall and leave the two TT wire ends apart - not touching

Disconnect the thermo sat wires at their other end, that will be at a zone valve OR at a circulator pump relay if you don't have zone valves; leave the two ends apart - not touching.

Then use a DMM or VOM in OHMS mode to see if there is continuity between the two wires - check both pairs of ends - if you see anything other than infinite resistance then the wires are shorted together somewhere en route.

Thermostat wires that are shorted together are functionally equivalent to the thermostat calling for heat forever.

See

inspectapedia.com/electric/DMM_VOM_Safety.php DMMs VOMs SAFE USE OF

and

inspectapedia.com/electric/DMM_How_to_Use.php DMM DIGITAL MULTIMETER HOW TO USE

OK so IF the TT wires are NOT shorted together

THEN there is either a bad zone relay controlling the circulator pump OR a bad zone valve relay that is not closing the zone valve OR a zone valve itself that is jammed "open".

On 2019-11-09 by Tyler

Having some trouble with one of my zones shutting off. Changed the thermostat and still won't stop. Any ideas to check?

On 2018-02-22 - by (mod) -

Oui Jean

R = Rouge (red)

W = Blanc (white)

B = Noir (black)

On 2018-02-22 by jean blanchette

pour être certain,l'aquastat pour bouilloire white rogers 11d05-1 les connections d'arrivée du courant sont bien dehaut en bas R pour rouge ,B pour noir etW pour blanc,MERCI, j.blanchette@hotmail.fr

Reader Question: Adding a third heating zone with its own zone valve

I am adding a third zone (basement) to my oil fired hot water baseboard heating and have it all planned as far as the plumbing is concerned.

The add-on heating zone will have it's own 24V zone valve so will require a wall mounted thermostat. I'm only looking for heat so I believe a 2 wire thermostat is sufficient. My other two zones have their own valves and thermostats and the wiring at the valves is all connected with wire nuts and doesn't make any sense to me.

I guess my question is, can I just connect my new valve and thermostat directly to the aquastat terminals that "appear" to power the other valves and thermostats ?

If so, is there anything I need to be aware of, like possibly wiring it backwards and frying something ?
If I can just add the new "loop" directly to the aquastat, in what order are the connections made ?

Example, aquastat to one connection at valve, 2nd connection at valve to one connection at thermostat, other connection at thermostat back to aquastat ?

If you need me to provide more detail on the types of thermostat, aquastat and zone valve I am using I can. My zone valve has two red wires and two yellow wires. The instructions seem to indicate that I only use the yellow wires and the red wires were for auxiliary, whatever that is. Would much appreciate your input. Thanks. - Will 11/10/11

Reply:

Will I think this will help clear things up a little for wiring a 3rd heating zone using a zone valve approach:

When the TT calls for heat (yes 2 wire is fine) it tells the zone valve for its zone to OPEN. When the zone valve is fully open it in turn tells the circulator pump to start pumping. (There is an "end switch" in the zone valve that performs this second function).

So you'll find a pair of wires from TT to the zone valve and a pair of wires from the zone valve to the circulator relay.

Watch out though: the wiring connections can vary a bit among zone valve brands - if all of yours are the same brand you can look at the existing valve, follow the wires, and you'll see how the zone valve is hooked up. If there are different brands you'll need to ask for a clue from your HVAC supplier or the manufacturer.

Reader follow-up:

Dan, thanks for the information. So I effectively have two circuits to connect. One 24v circuit runs in series as follows - transformer, zone valve, thermostat, transformer. Please can you confirm this.

The other circuit is simply connecting the other two wires on the zone valve to the connections on the circulator relay.

For the first circuit, do you know where my transformer is likely to be located ? I have the box on the front of my furnace which contains controls for how hot the water gets and when it needs to be heated. Would it be in there ?

For the second circuit to the relay, I'm assuming the relay is attached to the circulator pump itself.


...

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ZONE VALVE MANUALS & WIRING INDEX at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


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INDEX to RELATED ARTICLES: ARTICLE INDEX to HEATING BOILERS

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