Zone Valve Control FAQs-4

Zone Valve Motor / Head Install or Mount

What causes Honeywell zone valve to separate were the O ring sits ?

Why do or what causes Honeywell zone valve to separate where the o ring sits there are four screws holding it in place and one bolt lets go pushing the o ring out are these bolt acting like a shear pin On 2019-11-12 by neil -

Answer by (mod) - Honeywell V8043 Zone Valve Assembly, Parts, Separating

Neil

It sounds as if the actual valve body of your Honeywell zone valve is separating from the control head?

That's not a problem I've encountered except where someone or something was loosening the connection of control head to valve body. Vibration? Freezing?

If we assume for the moment that the proper zone valve head was selected to mount on the acutal mechanical zone valve base, I suspect the head was not properly installed, seated askew, OR the base itself has been damaged.

Can you post a photo so we have a clear idea what we're discussing?

Shown above an excerpt from ZONE VALVE MANUALS & WIRING

from the manual one of the Honeywell zone valve manuals at the link I gave above - the V8043

At ZONE VALVE MANUALS & WIRING you can download the manual for the V8043

How to replace Sparco PowerTrack zone actuators broken into pieces

Here is a pic of the system, any insight someone could provide on changing my zone valves and the steps I need to do to pull it off would be so appreciated!

I have 4, old, Sparco PowerTrack zone actuators on my system that are literally broken into pieces.

I want to replace them with more modern zone valves (was thinking the Honeywell 3/4” Sweat valves).

I have no experience with boiler systems but no how to sweat and do copper plumbing.

Can I just cut out the old actuators and install the new zone valves on my own?

I understand how to wire them.

I don’t know if I need to depressurize my system or drain it before I do any of that (or how to do those things, but would love to save my self hundreds to thousands of dollars from doing it myself). On 2021-05-24 by Trevor

Reply by (mod) replacement Sparco PowerTrack zone actuators from Honeywell.

@Trevor,

Forgive the slow reply - we've been swamped with questions.

plumbingsupply.com sells replacement Sparco PowerTrack zone actuators from Honeywell.

If the failure is the actual valve and not the motor then to repair these you'll need to

- cool down the heating system (turn it off and wait)

- drain off pressure and water from the lines enough that the piping in the area of work is empty (so it can be soldered) (open the boiler drain, using a hose to direct water to a safe drain location)

- disconnect and label the zone valve wiring connections - with POWER OFF

- cut out and sweat in new valves

- re-fill the heating system (assuming it's a water-only system)

- get the air out of the heating pipes so you won't be air-bound

(Search InspectApedia.com for AIR-BOUND HEATING SYSTEMS to see how we get the air out completely)

How to Override the Zone Valve - force open or force closed

Emergency use of the manual open lever on a zone valve or pushing the head down

I have 2 zones both with taco 571 valves. Zone 1 works fine but 2 doesn't.

I have 24v on 1and2 and turn up thermostat to 90 but it never opens, and I don't get any volts between 2 and 3.

I've tried replacing the head and still nothing? But it works in the open position? 2016-12-22 by Stephanie

Reply:

Stephanie:

For emergency heat you can manually open the valve by pushing the "manual" level in the valve head all the way down.

Having replaced the head, did you test to see that the valve body would open and close easily? It may be jamming.

Sometimes when the lever won't move the valve (or if your zone valve is a model that doesn't have an actuator override lever like the Honeywell zone valve in my photo) the service tech will simply remove the motor head entirely and use a pliers or wrench to manually turn the zone valve to its "open" position.

That can keep your heat on while you wait for a replacement of the failed zone valve. - Daniel Friedman

How do I override the zone valves on my heating or cooling system?

In my high-rise condo there are several 45-year-old McQuay/Daikin fan coil heat exchangers each with hot and cold water feed.

One unit has stopped blowing cool air. It's unclear to me whether the hot side is stuck open or the cool side stuck closed. Each side has a Honeywell line-voltage zone valve on one side of which is a "spigot"-type water valve and on the other a lever-type valve.

We are scheduled to have these HVAC units replaced in the next few years and, based on prior repairs to other of my units, I know this repair will require cutting open my drywall and run about $800.

I don't want to do that again knowing how short-term it is.

I'd like some advice on how I can manually override the zone valves. I can reach down through the exhaust duct and reach everything. Thanks. On 2019-05-09 by Mike

Reply by (mod) -

Mike

Typically the service tech will pull the zone valve head so that we can figure out if the problem is in the actuator motor, wiring, or other head problems, or if the problem is a corroded or jammed valve itself.

With the zone valve head removed, if the zone valve stem (exposed when the control head is removed) can be rotated easily with a small pair of pliers then the issue is the control head or wiring or a zone valve controller relay.

If the zone valve will turn then you can manually rotate it to the OPEN position.

And as you'll read in this article series on heating zone valves, some models such as many of the Honeywell zone valves have a manual over-ride lever that can be latched into the OPEN position.

by Mike

Thanks for your reply. My suspicion is that the zone valve on the hot side is stuck open.

Cool water comes in, but mixed with the hot water, it doesn't allow the circulating air to get cool. If I wanted to manually shut off the hot water, would it be done by closing the spigot on the hot line or by closing the lever valve? Or doesn't it matter?

Should the Macon Z60000 zone valve be set to Auto or Open? Heat won't turn off.

I have an older Actuator, the Macon Z60000.

It has two settings, Auto and Open.

Right now it is on "open" and my forced hot water baseboards are usually fairly warm, not hot, but you can tell heat is coming from them and this happens even when its 85 degrees and the thermostat is off and when the batteries are removed and it has no power(not hardwired).

Should it be set to "auto", it would seem that is the case as no matter what I do I can't stop the heat. On 2022-08-15 by Jeremy Actuator, the

Reply by InspectApedia-911 (mod) - "OPEN" position forces the valve to remain open all the time

@Jeremy,

Here is the

MACON Z6000 ZONE VALVE INSTRUCTION SHEET [PDF]

If the valve is working properly it should be running in AUTO.

The "OPEN" position forces the valve to remain open all the time - you may get heat when you don't want it - when there's no call for heat.

What happens is this: when the zone valve is forced "open" then hot water may circulate through the zone piping by normal convection (hot water rises, cool water falls in the piping loop) even when there is no call for heat and even when the circulator pump is not running.

How does the manual OPEN/CLOSE control work on a zone valve?

When I turn the zone valve manually to on, should

(1) the gears slip?

(2) the lever be pressed against the black button for the end switch?

I am wondering whether I have a defective zone valve (but it is new) as the gears feel like stripped gears when I slowly push to manual open and the lever wasn’t pressing against the black button so didn’t call for the boiler. - 2019-02-02 by Alex

by (mod) - zone valve gears are slipping, valve doesn't open

I suspect that the actual mechanical valve is jammed and needs replacement.

Followup by Alex

Here is a picture showing the lever not pressing on the black button but the manual switch is all the way open.

[Photo above-left]

Is there a wireless thermostat that can control heating zone valves?

I have zone zone valves and the wires going to thermostat are broken.

Is there wireless thermostats I could install to control them? On 2018-12-04 by George Stone

Reply by (mod) - Sources of wireless heating zone valves and zone controllers

George:

Sources of wireless heating zone valves and zone controllers

Honeywell provides heating zone control systems that can work wirelessly, including controls that can work with a smartphone app as well as a wireless thermostat.

Honeywell REDLINK

Honeywell Aquatrol

Also there's

Honeywell Wireless Zoning Adapter kit - YTH5320R1025 that includes Wireless FocusPRo Non-Programmable Thermostat and Wireless Adapter,

Also see HBX Control Systems' ZON-0550 is the first Wi-Fi enabled zoning control to the hydronic industry and can be used in many different applications from radiant heating to forced air delivery systems or a combination of both applications.

The ZON-0550 module has the capability to control up to four (4) THM-0300 or THM-0500 thermostats per controller and can operate pumps, valves or motorized dampers to provide heating and/or cooling to your HVAC system.

The control can be expandable up to a maximum of 20 zones that utilize wireless pairing communication.

The zone controller provides outputs (R-W-Y-G-X) for air delivery systems to control fancoils, furnaces, and air conditioning units. The zone outputs also allow for humidity control.

HBX Control Systems Inc.
Address:4516 112 Avenue SE
Calgary, AB, Canada
T2C 2K2
Website: http://www.hbxcontrols.com
Toll Free: +1 (855) 410 2341
Fax: +1 (403) 720 0054
Email:info@hbxcontrols.com
Support:support@hbxcontrols.com
© 2018 - HBX Control Systems Inc. Privacy/Legal Feedback youtube

Also Home Automation by JUNG includes wireless zone controls of which I've read mixed reviews.

All of the zones left in the manual "ON" position means you have heat while waiting for repair, but no zone control

My serviceman has ordered new zone valves but without them, my boiler is heating my house just fine in 18 degrees below zero.

He said he left it permanently on so I’d have heat. I have in floor heating. 2020-01-16 by Gwen

Reply:

However, Gwen, with all of the zones left in the manual "ON" position you have no zone control. That is, all heating zones are on all the time.

That may be just what you want when it's 18 below zero, but at warmer temperatures, in most buildings some areas need more heat than others. In that circumstance you'll reduce your heating cost and increase comfort by having working zone control.

Follow up:

Thank you for the reply. It is definitely not the zone valve of the zone valve control head as switched it with the one from Zone 1 and experienced the same issue. I also checked the 28V transformer although I knew it cannot be the issues as it supplies power to both zones. Chased the transformer wires to zone valves to ensure integrity, wires from the Aquastat are fine as well.

The Aquastat is connected to both zones outside of the unit so something was wrong with it zone 1 wouldn't be working as well. There is only 1 pump for both zones so it cannot be the issue either. For the last few days Zone 2 started to work normally but I haven't changed/ fixed anything besides replacing the Zone 2 valve head but the issue persisted at that time.

My guess is that Rh or W1 wires are damaged somewhere inside walls and when it gets colder at night they lose the contact. But that is a very wild guess as I noticed the issue happening exactly at 10PM on those days.

Reply:

Changing the zone valve head is a good diagnostic step to rule out. Component, but if the zone valve is still sticking open or closed the problem could be the mechanical valve itself that is a valve body.

And like you I don't rule out and intermittent poor Connection in the thermostat wires themselves.

Sometimes you can detect a problem by checking for continuity between the wires after disconnecting them from the thermostat at one end and the zone valve at the other.

You can also try temporarily switching the zone valve directly by substituting a jumper for the thermostat

See solutions at COMMON WIRE at THERMOSTATS

Follow up:

Great minds think alike! This weekend temperatures dropped to the lower 30 again and the Zone 2 quit working.

I found the old thermostat (with batteries) and the remainder of the 18 gauge wire that I used to run C wires from haulers to ecobees and connected that wire on one end to the Rh wire from the 24V transformer to thermostat and W1 wire from thermostat to zone valve.

The other end connected to the old thermostat.

When I call for heat using the old thermostat the zone valve opens the mechanical valve... heat works every single time I test/ use it instead of turning on the zone valve manually.

At the same time when I test the Rh and W1 wires upstairs there is 0 voltage.

Interestingly, testing Rh with Y gives 5-6V. So it looks like it is the thermostat to transformer/ zone valve issue.

The worst of all possible outcomes, as there is no way to run a new wire without opening walls on 1 and 2 floors.

Unless there is some kind of device that I can hook up to ecobee and downstairs that will communicate to each other(maybe something could be built using 2 rasberry pi).

Half my house is freezing cold - I need emergency zone valve repair

I have dual zone water heater. One zone isn't working when thermostat calls for heat but other is fine.

Can I out the switch to manual open? And if I do should I shut of thermostat for that zone? This way when other zone calls for heat it can cycle hot water to both zones.

Half my house is freezing and need to find parts and get fixed. Sending a pic of my two zone switches or gates I think On 2018-11-13 by Justin -

by (mod) - how to open a zone valve by hand - manual lever - to override or force the zone valve to remain "open"

Maybe, Justin.

There is a manual zone valve switch that can be used to latch your zone valves into the OPEN position - pointed to by the yellow arrow in my clip from your photo.

Slide the lever to the right until it latches under the protrusion from the top of the horizontal lever slot.

However one mode of zone valve failure is the jamming of the mechanical valve itself. If this has happened you will find that you can't move the lever to latch into the open position.

Reader note: some zone valve models can be moved to the "open" position by turning a wheel in the bottom of the valve. Other models may not have a manual wheel or lever to open the valve.

Priority Zone Valve Feature

Two zone valves on boiler, but one won't go on unless the other one is also on

I have 2 zone valves on my boiler and zone1 will not go on if zone2 is not on. When zone 2 is on everything works good.Is this a bad valve or a wiring issue. - Frank 10/8/2012

Reply:

Frank, if you mean that the zone valve itself does not operate or it's end switch does not turn on the boiler unless another zone valve is on then it's likely to be a wiring problem.

Watch out for the case of two different zone valve brands - sometimes their wiring hookup details are different.

First floor heating zone won't run unless second floor zone is on

I have 2 zone water baseboard heating.

Recently we found 1st floor (zone 1) can't turn on by the thermostat unless the 2nd floor (zone 2) is on On 2017-12-12 by Joy

by (mod) - turn off priority zone feature

Joy

That sounds like either there is a wiring error or perhaps the zone 1 circulator isn't running so that zone won't get heat unless both zone valves are open and zone 2 circulator is running (perhaps abetted by the pipe arrangement of your system so that circ 2 will push water through both zones)

Ask your heating service tech if your heating zone controls include a "priority zone" feature. If so, that may simply need to be turned off

Other zone valves won't run unless I raise one particular zone thermostat on my 4 honeywell V8043E1012 zone valve System eith a Dunkirk Helix boiler

Once I lower the thermostat a few degrees on my hot water baseboard system, one of the thermostats calling for heats is preventing others to cycle.

Once I raise that stat a few degrees, others begin to cycle.

Is this a bad zone valve motor in the one? 4 honeywell V8043E1012 zone valve. It's a Dunkirk Helix boiler. - On 2018-01-02 by Mike A

Reply by (mod) - look for a priority zone heating system set-up

Mike

if your heat used to work correctly and no one has made any changes in the wiring then I have to rule out a wiring error. However that was my first guess. My second guess is a problem with a wiring connection or a bad relay that is not turning on your circulator pump.

In general, in normal wiring no thermostat should affect the operation of the other thermostats. You might if this is an old problem follow the wiring connections.

But on some newer heating systems there is one "priority" thermostat connection or zone valve that is intended to give boiler-heat priority to the domestic hot water heat production - such as for an indirect water heater.

That's so we give priority to the person standing in the shower over the folks who are sitting dressed in some other room.

So if the wrong zone - the one intended for a domestic hot water heater - is controlling a space heating zone instead, that needs to be reconfigured or its priority feature simply turned off.

by Mike A

yes i saw that its by itself. Any ideas on why that 1 zone shuts the others that are already on off ?

by (mod) - zone valve for indirect fired water heater

To be clear

Some zone controllers use one specific connection point for the water heater. Do not connect a regular heating zone thermostat there.

Followup by Mike A

yes mine has that plus water tank has its own circulator pump when dominating stat is disconnected all others work.

Also the dominating zone valve is a newer Honeywell others are older.

No one was using the hot water i noticed this issue at 4am today I'm puzzled not sure if the motor became stuck open preventing others to open seems odd.

Dan also the hot water heater was on and did not prioritize over hea, but once I turned on dominating stat with others on already it shut off all other demands except water demand ? puzzled..

I just tried this turned on other stats waited 30 sec then turned on dominant stat once I did that the others stopped calling for heat?

What happens if you disconnect the bad or dominating thermostat at the control box

What happens if you disconnect the bad or dominating thermostat at the control box? If all of the other's work properly that I would look at the connection points in the control box.

Some control boxes have a connection for the a tankless water heater which will automatically switch off companion heating zones when there's a call for domestic hot water.

Dan the pump works fine problem is when heat is calling from the one stat no others turn on with temps it those zones fall but the stats are calling for heat in the falling temp zones.

The control box in basement near boiler only shows the one stat calling for heat none of the others are but all stats in the rooms are calling for heat. On 2018-01-02 by Mike A

Strange & Interesting Zone Valve Q&A

Switching from an oil burning boiler to a high efficiency gas Bosh boiler resuing old Taco zone valves - boiler overheat risk?

I am switching from an oil burning boiler to a high efficiency gas Bosh boiler. I have two bids differing by about $1400.

The bids cover the same thing except that the higher bid calls for redoing the piping from the new boiler into the heat zones and replacing the old Taco zone valves with new zone valves that would open instantly when heat was called for, the other bid reuses all the piping as is and retains the old zone valves.

The reason given was that the Taco valves take time to open and that the new boiler would tend to overheat waiting for that valve to open. Is that a real concern or are the Taco valves fine for the new 95% efficient gas furnace? 2017-04-22 by David Mills

Reply: will the boiler overheat while waiting for the zone valve to open?

I don't understand what the higher bid contractor is actually thinking; Why would a boiler over-heat; it is controlled by its aquastat settings. Furthermore, what are we talking about here - a matter of seconds, not even minutes, for a zone valve to open.

However if the Taco zone valves are quite old it'd make sense to install new units for reliability. Still why on earth that would require complete re-piping of all of the zone piping leaves me confounded.

For an authoritative answer you could try calling the boiler manufacturer's tech support line - be tactful and taciturn - they won't want to irritate the contractor whom they probably consider their "real" customer.

Is a zone valve required on a single zone, in slab system - Do I need a Zone Valve at all?

Stupid question here, is a zone valve required on a single zone, in slab system?

Combi-boiler feeding indirect HWT and single zone in slab that has three loops of that helps for background information. The in-slab is not the primary source of heat for the area as well. On 2022-11-12 by Ben

Answer by InspectApedia (Editor) -

@Ben,

Typically the indirect hot water tank will be fed as a separate heating zone so you would need a zone valve that opens or closes between the boiler and that tank.

Therefore you ought to have a second zone valve to control the building heating loop.

That allows the two separate uses of the boiler to operate independently of one another.

Can replacing a hot water tank affect a zone valve?

Would the zone control valves have been affected when a hot water tank was replaced? (Apr 8, 2014) Carpenter

Reply:

Carpenter,

It seems unlikely that replacing a hot water tank would affect heating zone controls with the following exceptions:

IF you were replacing an indirect-fired hot water tank that is heated by a separate heating boiler, the hot water tank acts as a separate heating zone on the heating system; if the tank replacement technician messed with controls or wiring on that heating zone then it may be operating differently or improperly.

IF when the water heater was replaced someone accidentally (or out of ignorance) bumped into or messed with a zone control (say trying to find the one that operated the indirect water heater) that might have led to an embarrassing snafu that someone may be reluctant to admit.

Reader follow-up:

Ch and hot water were on constantly and not responding to control panel and still on after set to 'off'.

This followed hot water tank replacement. We had to employ different heating company who have sorted valves but my 86 year old mother is left with gas bill of over £400 as a result of this fault.

The original technician said he did not need to check everything worked ok as he was only replacing tank! Incidentally, the top of the tank had erupted like an open flower,it wasn't just leaking.

Could this have been caused by valve malfunction to begin with and therefore should have been checked?

The bill and gas charge together are £800 and I think we will just have to accept it! Thanks for your info.

Reply:

Carpenter,

What an aggravating snafu. It sounds as if there were multiple faults, and with the apology for sounding like a fussy old lady (I'm not, I'm a fussy old man), you all are darn lucky nobody got killed by a BLEVE explosion when that water tank ruptured. If you can send us some photos please do so, using the CONTACT link found at page bottom and I can comment further.

For a hot water tank (geyser) to burst open under over-pressure it is possible that it was not properly protected by a temperature & pressure relief valve.

It also sounds as if perhaps the original technician MIGHT have crossed up some control wires, not wired them correctly, been confused about which zone control was for hot water, or something like that.

And it also sounds as if possibly a temperature upper limit control was not connected or not working - which is mere speculation on my part since even at over temperature the TP relief valve should have been installed and should have opened.

There are other possible errors such as someone shutting off a water valve that left the system with no place to push expanding pressure.

It's not reasonable for us to diagnose too exactly what happened just based on a few text notes, but certainly it sounds as if improper installation, controls, safety devices, and possibly operation all were involved, and most critically:

you want assurance that a qualified expert plumber has examined the system for proper installation, safety, and building code compliance.

How far does a zone valve open

How far should a zone valve open ? Mine appears to only open slightly.

Wondering if the lever should move all the way to the left. (Nov 14, 2014) Mike r

Reply:

Varies by model, but generally 180 degrees; the lever moves fully to the OPEN position.

How do I know how many zones do I have?

How do I know how many zones do I have if I see 3 cold & 3 hoot lines in my furnace room, 6 lines total from the floor - 7 Feb 2015 Sharon

Reply:

Chris

Normally each heating zone has its own thermostat. Count thermostats.

Should I turn off the zone circulator while my heating system is down for repairs?

I have a boiler that is down and want to know if the circulation pump (multi zone) should be turned off of left on while the system is fixed (2 days)?

Any harm either way? On 2017-12-28 by Stevec

Reply by (mod) - keep the circulator running to reduce risk of frozen heating pipes

While it won't protect the rest of your house from freezing, you might reduce the risk of frozen heating zone pipes by keeping the circulator pump on during the "down time" for your boiler.

But

Watch out: depending on what repair is needed at the boiler, if the system pipes have to be opened and/or partly drained to do the boiler repair, the circulator will need to be OFF - at least in part to avoid risking damaging the circulator impeller by running it while "dry".

Is installing a new zone valve easy?

I have a gas fired hot water baseboard system with two zones.

The lower zone is not working,could this be a faulty zone valve and are they easy to install if I bought one? Plumbers in our area are really swamped now after H.Sandy, so I was going to try it myself. Am I asking for trouble? 2012-12-17 by RJ

Reply:

RJ,

Installing a new zone valve typically involves cutting out the old one, draining the system enough to solder in the new one, wiring up the new one, and bleeding any air out of the system.

If there are isolation valves on either side of the zone valve (usually not there) the job would be easier;

I can't say what's easy or not for someone I don't know - it's basic plumbing plus heating knowledge necessary to wire the valve (read the instructions and copy the old hookup if the valve is the same brand and model) and knowledge necessary to bleed air out of the system if neeeded.

InspectApedia also offers articles on how to bleed air from the system.

Which zone valve brand is best?

I'm replacing boiler zone valves (have boiler serving 8 condominium units), which is better: Taco zone actuator or Honeywell mechanical valve? On 2020-09-21 by Anonymous-

Reply by (mod) -

Anon:

Heating System Zone Valve Failure Rates, Failure Data, Honeywell vs Taco [ Vs other brands including B&G, Bell & Gosset)

Thank you for a helpful question on the reliability or quality of Taco vs Honeywell zone valves and actuators.

I have used, installed, and repaired both brands of zone valves since the 1970s; In the northeastern U.S. I've seen more Honeywell than Taco zone valves installed, but I have no actual zone valve failure rate data that demonstrates one BRAND is "better" than the other.

Reading comments by various HVAC service techs we see an OPINION that "which is better" Honeywell or Taco turns in part on which zone valve model you're installing.

I've seen some complaints about the TACO No. 271 and other complaints about the TACO 500 series and I've seen kudos and praise of the TACO ZVC series zone valves.

"Complaints" are anecdotal reports, not peer-reviewed expert research on failure rates.

It's likely that both Taco and Honeywell have failure data for their products based on their own research, on field reports, or both. But I've not found that data available to the public.

Bottom line: Both Honeywell and Taco make reliable zone valves.

But Watch out: wiring a MIX of the two brands on a single heating system requires some care as the two brands are not wired identically.

We discuss that in this article series.

What is the point of a zone valve in the extension radiator loop

I have a boiler in an extension that provides hot water to the kitchen and extension.

The hot water and CH (central heating) in the original house are provided via a 22mm feed from the boiler via a Dunsley Nutraliser to the house radiators and bathroom hot water. All this works fine. All radiators have thermostatic valves to control the heat in individual rooms.

However, the 2 radiators in the extension are tapped off the 22mm feed to the main house and have a 2 port Honeywell Motorised Zone Valve in the loop (not in the 22mm).

This seems to have stopped working as the radiators were cold even with the Thermostatic Valves fully open.

Head has been removed and valve now moves very freely using very little finger force.

Checking the wiring (5 wire) against a wiring diagram the orange wire goes to a connecting block but no further. This was a professional installation not DIY.

My understanding is that the orange is normally intended as a feed to tell the boiler to fire. However the boiler fires fine and must be getting signals from other valves within the boiler itself.

What is the point of this valve in the extension radiator loop as it just seems to get a signal to open from the controller, take a few seconds to open and then stay open until the programmer switches it off and the spring closes it?

Seems to be an unnecessary component in the system. Thanks On 2021-02-19 by Dafydd

Reply by (mod)

I have made the mistake of removing and tossing a part whose function I couldn't understand.

Usually people don't go to the trouble of installing a valve or control unless it was needed.

But yeah, there can indeed be a "left-over" control from discontinued equipment or devices.

First let's get heat back: for those two zone valves: try putting the valve in the MANUAL OPEN position to see if that restores heat; that'll be diagnostic.

If the valve is open and you still have no heat in those zones and the circulator is - for sure - running, then in the ARTICLE INDEX see our advice on troubleshooting an AIRBOUND HEATING SYSTEM

Why add a zone valve? to have automatic control of heat in the location that the zone-valve-fed radiator(s) or baseboards enjoy.