Hot water heating system zone valve diagnosis & repair:

Frequently-asked questions about heating zone valves on hot water (hydronic) heating systems.

This article series helps troubleshoot and fix problems with zone valves on hot water (hydronic) heating systems.

Hot Water Heating System Zone Valve Diagnostic FAQs

These hot water heating zone valve questions & answers were posted originally

at ZONE VALVES, HEATING - you should see the repair advice given there.

On 2020-09-12 by (mod) - how to replace a heating system zone valve without using solder or sweat fittings

Thomas

How to replace a zone valve without having to sweat (solder) connections:

Zone valves are pretty generic and interchangeable, with the caveat that you have to look carefully at the wiring connections to get that right. Those details are in manuals found at ZONE VALVE MANUALS & WIRING INDEX

To connect a zone valve without soldering copper (sweat connections), you'd need to buy a valve that uses threaded pipe (in the U.S that's NPT threading) connections.

Here's an example of a zone valve that connects by providing female NPT threaded connections

- this is a Belimo zone valve sold by https://bostonaircontrols.com/ and others.

I'm not touting this particular brand nor any other specific product.

You could try SharkBIte non-sweat push-type connectors like a 3/4-inch SharkBite push-to-connect coupling.

Do not try using PEX tubing as the heating system temperatures are likely to exceed the PEX maximum (typically 130F).

But SharkBite, used in an all-copper system can work.

"SharkBite Universal fittings have a maximum temperature of 200°F maximum pressure 200 psi when used on copper pipe."

Here's a SharkBite 3/4" copper connector that sports male NPT on one end.

You'll need to use either a coupling (shown below) or a SharkBite connector that provided a male NPT fitting on one end

- to connect to the new zone valve, and a push-to-connect to copper fitting for (probably 3/4") copper heating zone piping on its other end.

[Click to enlarge any image]

Below is a photo showing typical Sharkbite connectors, in this case where I was hooking up a Bosch tankless water heater to a control valve and a service drain.

On 2020-09-12 by Thomas

I was wondering If I could replace a 40004850-001 Honeywell end-zone valve with some other replacement Zone Valve. Preferably the NON SWEAT type .

I have a 3 Zone system and a brand new thermostat on this zone and the other two zones respond when I call for Heat but this one doesn't. It looks like water got into It from the top. All 3 were replace about 5 years ag

On 2020-05-11 - by (mod) -

Jack

Thanks for asking a great question. Yes, we've had reports of water hammer from a too-fast closing zone valve, combined with high velocity circulation of water in the zone.

On 2020-05-11 by jack

Can a zone valve in a residential hot water system that closes too fast cause water hammer?

On 2020-03-02 by Anonymous

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).

On 2020-02-27 - by (mod) -

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

On 2020-02-27 by Anonymous

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.

On 2020-01-16 - by (mod) -

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.

On 2020-01-16 by Gwen

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.

On 2019-11-12 - by (mod) - what causes Honeywell zone valve to separate were the o ring sits there are four screws holding

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?

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

Below is an excerpt from ZONE VALVE MANUALS & WIRING https://inspectapedia.com/heat/Zone_Valve_Wiring.php

from the manual one of the Honeywell zone valve manuals at the link I gave above - the V8043 [Click to enlarge any image]

On 2019-11-12 by neil

why do or what causes Honeywell zone valve to separate were 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 2017-07-15 by (mod) where to find dissolved-resistant zone valves

Denys,

Thank you for asking - I've done more research on dissolved oxygen issues for heating systems - please see a detailed reply to your question, now found at

DISSOLVED OXYGEN DAMAGE CONTROL - inspectapedia.com/heat/Dissolved-Oxygen-Damage-Prevention.php

I've asked Honeywell if the company specifically recommends any particular zone valve models as resistant to dissolved oxygen as I haven't found such products. Meanwhile at the article I cite you'll see how industry experts suggest avoiding damage from dissolved oxgyen in residential boilers.

On 2017-07-15 by Denys

Question: are there zone valves that resist damage from dissolved oxygen in hydronic heating system boiler water

Denys Picard said:

Honeywell warns that makeup water feed to a boiler may damage the rubber plug of Zone Valves 8043 and make them fail.

Are they zone valves resistant to dissolved oxygen from makeup water feed? Thank you.

On 2017-07-15 by David

Thank you for the answer and reference research, as I am not familiar with these equipements, I tend to read all instructions carefully. And yes, I have an open loop system that feeds on my softened and filtered well water, but my heating system is well equiped with many automated gas purging devices

.I hope it will be enough to ensure good performance for a reasonable time. I guess that all other brands also do put this caution then.

On 2017-05-19 by (mod) - ticking zone valves

David:

If the valve ticking stops after the system has cooled down I suspect it's thermal contraction; sometimes using plastic noise reducing pipe mounts can reduce or even eliminate that problem.

If the zone valve is ticking continuously and never stops that sounds like a failed or jammed zone motor and the valve head probably needs replacement.

On 2017-05-18 by David

We have a two-port motorised valve that makes a ticking noise when the hot water is switched off.

Is there anything that can be done about this?

On 2016-12-26 by (mod) - no heat: thermostat exposed to drafts? Overheating zone motor?

Perhaps there is a draft r at or in the wall cooling the thermostat,or the temperature sensor could be dust blocked.

If with the motor-head removed from the zone valve you cannot easily open the zone valve then it needs replacement.

If you can open the valve but the line never gets hot, I suspect the line to that zone is air blocked. In that case,search InspectAPedia.com for AIR BOUND HEATING SYSTEM to read repair details.

On 2016-12-26 by Steve

I moved it to manual but it didn't turn over in that zone. So I moved it back. As I raised the other zone upstairs the lower zone started to kick in. That's why I was wondering if it could be the motor of the zone valve.

On 2016-12-26 by (mod) could a bad zone motor explain it sticking?

See if the zone valve is stuck shut; see if you can latch the valve in a manual OPEN position.

On 2016-12-25 by Steve

Hello I could use some advise. I have a two zone heating system. They were both just working fine but now the lower level stays cold and only gets warm when the upper level kicks in. I changed the lower thermostat but the problem persist.

A year ago I had the upper valve changed and it was suggested then that the other one would need to be replaced soon. Does this appear to be my problem now, that I need a new zone valve motor for the lower level.

On 2016-12-22 by (mod) emergency use of the manual open lever on a zone valve or pushing the head down

Stephane:

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.

On 2016-12-22 by Stephanie

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?

On 2016-12-22 by (mod) - too many thermostats & zone valves on one power transformer

Al,

Perhaps 7 thermostats is 3 more than a single power transformer can support - or if the setup uses 2 transformers you may have blown one.

On 2016-12-21 20:53:47.644169 by Al

I have a 7 zone heating system with thermostats. I was trying to replace honeywell thermostat with nest, when i un-installed the thermostat and installed nest, i noticed that i lost power and nest was not functioning.

my other two rooms also lost heat because they are wired to the same transformer(however, the other two rooms have power just no heat). Is this a bad transformer issue or something else?

On 2016-12-13 by George

I have a 7 zone heating system with thermostats. In two of the rooms the thermostat is set a 63, but the heat goes up to 79. What could the problem be?

On 2016-12-13 13:03:05.522294 by (mod) Drayton ZA5 zone actuators & multiple controls

Logically one, either, or both thermostats should work to call for heat. No third control is used. Perhaps one reversed low voltage wires.

On 2016-12-13 08:19:05.911904 by Dafydd

I have added underfloor heating to my system and made it a 2 zone heating system. Both zones operate independently of each other and fire the boiler up as expected but I'm having issues with both thermostats calling for heat at the same time and both valves being closed. I know this will be a wiring issue requiring a signal from somewhere to ensure this does not happen.
My wiring is very close to the S plan wiring.

I have Drayton ZA5 zone actuators
My boiler is a Veissman Vitodens 100
My room thermostats are Honeywell Wireless CM927

I know this is a wiring issue but I can't see to find a solution.

On 2016-11-03 by Mike Rose Taco zone controller

I have a Taco zone controller on my furnace, professionally installed, but the issue is that even after tightening the screws down holding the wires securely, they keep loosening up. Then I notice a zone is cold, go down and tighten them up again and the zone immediately kicks in. Is there some known issue with Taco controls? This unit is mounted on the furnace itself, vibration? Cure? Thanks.

On 2016-06-06 by (mod) thermostats not working right - shorted wires?

Check for thermostat wires shorted together

On 2016-06-06 by Roland

Thermostat work only once wayatwe running I mean always hot water running,no regard the position of the thermostat imean high or low open or closed n.b. brand new motor valve

On 2016-04-26 by Shaun

Had an indirect HW tank go on my gas 3 zone HW system & went with a new set up having an electric HW tank wired direct to my circuit box. Problems of all kinds.
Heat not working. Utica boiler (usc5) will fire up and then shut down after 15 sec or so.

Called hvcc people back and they are now telling me after a $226 service call/estimate that all 3 of my Erie zone valves are bad and need to be replaced.

What are the chances of all 3 valves going at the same time? When they cut the pipes to remove the old indirect tank and wired the new tank (by the way they piggybacked it on the panel cause there was not enough room) could that have somehow damaged my 3 zone valves (the 4th was for the old HW tank and pipe was capped but wiring was just left)?

Other bad news is that when i took my 1st bath with the new 50gallon HW tank, the HW stopped about 1/4 of the way in filling and turned cool. What gives? Granted the tub is at the opposite end of the house but the old 40 gallon tank had no problem filling the tub with hot water.

On 2016-01-23 by (mod) zone valves for radiant heat

Check that the zone valve you are using is designed for use with your radiant heat system; also check the low voltage power supply.

On 2016-01-20 by Bruce

The radiant heat component of our heating system was calling for heat 24/7 but the heat was barely trickling in. I replaced the zone valve that was the problem. The new one has the same problem - it only opens partially. I have to manually open it all the way.

It stays fully open until the thermostat stops calling for heat. Both zone valves then close. When heat is called for again, it only opens partially, and, again, the boiler is on almost constantly, with the heat barely trickling in, unless I manually fully open it. Thoughts? Thanks.

On 2016-01-01 by (mod) basic zone valve wiring debugging

Denis:

This may help:

On a call for heat the thermostat is acting as a simple "on-off" switch. Connected to 2 wires at the zone valve, it tells the valve motor to open to permit hot water to flow into the zone.

When the valve motor has turned to fully open water flow, and end switch in the valve control head connects two more wires that tell the circulator to start. That's the usual 4-wire Honeywell zone valve set-up.

If your circulator pump relay is not working then either we've made an error in wiring or the zone valve end switch isn't working.

But there are compatability and wiring errors that come up if we mix two different brands of zone valves on the same system, both of which are trying to turn on the circulator pump. To sort that out we need to know both brands and to look at their wiring instructions.

I've run into this trouble myself - I used to call Dave Ferris at GEM supply in Poughkeepsie and Dave would say "oh yeah - for that, just connect the yellow wire to terminal X" - but Dave has retired.

Take a look at

https://inspectapedia.com/heat/Zone_Valve_Wiring.php

that may help.

On 2016-01-01 by Denis

The valves are just out of the box. I have only one that is wired for the moment & suspecting a faulty valve head was in my trouble shooting sequence. So I tried on a head from another not yet installed valve & the problem persisted.

As is, the zone is operating beacause as statted before, the valve opens when the thermostat asks it to do so.

But since the pump contactor did not energise, I've used a spare thermostat to feed the it. So 1 thermostat operates the valve & the other one operates the pump contactor who feeds the heating element contactors.I didn't think it would help but I have also inversed the leads at the feeding transfo to no avail.

On 2015-12-29 by (mod) problem with the zone valve control head end switch

This sounds like a problem with the zone valve control head end switch.

Indeed I've run into wiring questions when mixing brands of valves.... more asap

On 2015-12-28 by denis maringouin The Taco zone valve wiring

New taco zone valve does not energise the circ. pump contactor.

Hi,

I finally figured out why I keep burning out my magnetic contactors that feed the elements in my electric domestic boiler! The Honeywell zone valve end switches cause the magnetic contactors to chatter. As a result, they overheat and burn.

I’ve had technicians change the 2 main contactors 4 times in the past 30 years & they have burned once more. I knew something had to be causing these failures & that it was not just the contactors that where failing so I started investigating & I figured it out that the end switches where the culprits.

I found 2 new contactors on line & also purchased new Taco 571 valves. Replacing the contactors was a breeze but I’m stuck on the valves.

The old Honeywell valves have 4 wires, 2 for the valve & 2 on the micro end switch. The Taco valves have only 3 wires.

The diagram for the Taco valve shows:

- 1 wire from the transformer that goes to feed the thermostat & continues on to the # 1 terminal on the valve.

- The 2nd wire from the transformer goes to

A:- the # 2 terminal on the valve,
B:- one pole on the circ. pump magnetic contactor.

- The 3rd terminal on the valve goes to the other pole for the circ. pump magnetic contactor.

I figure this to mean that; the #2 contact on the valve is common to the thermostat & the circ. pump magnetic contactor.
Therefore:

(a):- the thermostat circuit is completed from the transfo, to contact #2 on valve, out at contact #1, through the thermostat & back to the transfo.

(b):- the end switch circuit is completed from the transfo, to 1 pole for the circ. pump magnetic contactor , to #2 contact on the valve, out contact #3 on the valve & back to the other pole on the circ. pump magnetic contactor.

This means that when the thermostat closes & makes contact, it open the valve which when open should close the end switch that should energise the circ. pump magnetic contactor that in turn should energise the 2 sequenced element contactors.

Well, nothing is ever easy!! It doesn’t work

The valve opens but the circ. pump magnetic contactor does not energise.

Can someone help me? Thanks, Denis.

On 2015-11-24 by (mod) possible bad zone valve motor

Valve

The issue can be in the motor - that can be replaced without removing the valve body -
or in the valve assembly itself.

Pull the motor and see if you can easily rotate the valve stem.

On 2015-11-23 by valve sticks on

I find that sometimes one of my zone valves will stick on causing my house to overheat. If I tap it with a wrench, it will click off. Lately it has happened more often so I need to correct it. Do you think I need to replace the whole valve or just the actuator motor assy?

On 2015-11-07 by (mod) unwanted heat in one zone

Look for

- thermostat wires shorted together

- a zone valve stuck open

- a flow control valve at the boiler stuck open or manually in open position

On 2015-11-06 by Fred

I have a 2 zone hot water baseboard the upstairs baseboard is hot with the thermostat turned off

On 2015-05-07 by (mod) stuck zone valve diagnosis

Help

I'm concerned that if the zone valve is stuck open the problem may be in the valve body not the motor. Remove the motor or "head" from the valve and see if the valve itself is jammed. If so the whole valve needs replacement.

On 2015-05-07 by Help

I have a 2 zone heating system (3 if you include the hot water). Zone 1 and hot water work fine. Zone 2 is stuck in open position (Honeywell 8043f, lever has no resistance). Zone 2 only (and always) provides heat if hot water or zone 1 is requesting heat.

However, if Zone 2's thermostat is requesting heat, the circulator and furnace do not come on. This is a one circulator system. I think I have to replace the motor of the Honeywell8043, but not sure, since it doesn't work when the thermostat is requesting heat.

 

On 2017-06-25 by Rob

Can anyone tell me why I have two inline zone valves on my hot water system? And one on my central heating?

On 2017-05-05 by Wayne Rife

The reason the higher contractor wants to replace the piping is to create more work and make more money.

On 2017-04-22 by (mod) switching from an oil burning boiler to a high efficiency gas Bosh boiler

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.

On 2017-04-22 by David Mills

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?

On 2017-03-11 by (mod) - where are the zone valves located?

Shibu

Take a look at the photos at ZONE VALVES, HEATING - you can see the mostly silver-covered zone valves - usually located near the boiler and best, on the cooler return-side of the heat piping loop. But a zone valve can be located at more remote spots too if a heating zone loop splits into a sub-loop elsewhere in the building.

The thermostat controls the zone valve, telling it to open or close in response to a call for heat. The zone valve, when it is fully open, closes an "end switch" that turns on the circulator pump - in most designs, though in some countries installers keep the circulator on all the time - in that case the zone valve just opens or closes.

The temperature of the water turns the boiler on or off.

Search InspectApedia using the InspectApedia serarch at the top or bottom of any page, looking for ZONE VALVE WIRING to see typical wiring diagrams for all of the common zone valve brands and types.

On 2017-03-11 by shibu

hi can any body hive zone valve installation working procedure ,where the location in heating systems
thanks shibu

On 2017-02-17 by (mod) are zone valves ball valves?

Yes or stop valves. Most models are not the more-reliable (and more costly) gate valves.

On 2017-02-17 by Bob B

Are these valves just ball valves?

https://inspectapedia.com/heat/Zone_Valves_010_DJFcs.jpg

On 2016-12-09 by (mod)

What return, anon? If you mean the zone valve: it's normally fully open or fully closed.

On 2016-12-09 by Anonymous

I just want to know if I should have my return fully open or partially open

On 2016-12-04 by Dan

Thanks , my installer has just come back to me and has also said that it doesn't sound right. I'll see what I can do about a replacement. Thanks for your reply. Dan

On 2016-12-01 16:47:41.029481 by (mod)

Dan:

Buzzing zone control sounds unusual, perhaps a failing low voltage transformer or a valve that's jamming.

On 2016-12-01 by (mod) taco zone valve is not shutting off when desired temp is reached

Joe,

If nobody changed the wiring then more likely the valve is jammed open or its motor has failed. Can you manually close the valve? If so, try that. IF you can't move the mechanical valve parts then the zone control needs replacement.

On 2016-12-01 by joe

my taco zone valve is not shutting off when desired temp is reached, it is staying in the open position .is this caused from thermostat wiring into relay being backwards?

On 2016-11-30 by Dan

I've just had 2 zone valves (Sunvic) fitted to separately control under-floor hearing in one room and the central heating in the rest of the house.

When the valves open or close there is a loud noisy buzz for 45 seconds or so. Is there such a thing as a silent (or at least very quiet) actuator? The noise is driving myself and Mrs Dan mad... Thanks

Moderator reply:

Dan take a look at the diagnostics and cures

at HEATING SYSTEM BUZZING NOISE

On 2016-11-29 by john a - wrong voltage at the thermostat?

I have a 3 zone system on a boiler unit.

Each zone has a valve and relay and 1 thermostats. problem is i have a thermo runaway on 1 of the zones, I pulled the thermostat and the radiators for that zone cooled down. I replaced the thermostat and all seemed fine for a day, now back to thermo runaway.

I checked the voltage and i get 75 volts at the thermostat, that does not sound right to me (24 v system). I get 24 volts out of transformer, goes through small circuit board and ups to 75 volts. Is this the operating voltage for the zone relays or valves? what can cause the 75 volts on the thermostat from the system?

On 2016-11-27 by Anonymous

I HAVE 8 ZONE VALVE DO I TO BLEED THEN EVERY YEAR AND WHAT THE BEST WAY

On 2016-10-20 by (mod) voltage drops when 7 zone valves are on one transformer

Good question, Andre.

We often read about people hooking up too many zone valves to a single transformer, overloading it. When updating this article I'll be sure to include your helpful comment.

Readers should also see -LOW VOLTAGE TRANSFORMER TEST
and
also see ZONE VALVE MANUALS & WIRING INDEX

On 2016-10-20 by Andre - make sure they have at least a 75VA transformer for the valves

Just curious about the query whose 7 zone valves keep failing once a year. I wonder what the rating on the transformer is? If it's a standard 40VA like you find on a lot of equipment from the factory, 7 of those valves will try to draw 60VA if they all open at once.

The voltage will sag, the current will go through the4 roof, and you'l burn the windings on those tiny synchronous motors. And this is not just an instantaneous short either - once those valves start going, they keep going as long as necessary.

Readers should make sure they have at least a 75VA transformer for the valves - 60VA for full load plus 20% headroom.

On 2013-02-19 by Karl

Can I put a shut off valve in the supply side of my two zone oil fired hot water. The zone has a shut off at the circulator on there return side. But if I want to isolate one zone (for repairs, busted pipe), and the only way is to shut off the water to the furnace, thus shouting down both zones. I just wasn't sure if the was something I was missing.
Thank you
Karl

On 2013-02-08 by steve

have a gas heat boiler that keeps overheating it starts banging and the relief valve goes off have replaced circ pump expansion tank relief valve zone control panel supply valve and problem is still there boiler is a super hot Saturn series

On 2013-02-01 by Austin

I recently had a plumber remove one register of our baseboard heat in the basement. We have three zones and now it seems the two zones for the upstairs are running concurrently. I have the third zone shut all the way down on the thermostat and it still seems to run when the second zone is turned on. What can I check that the plumber might have messed with?

On 2013-01-08 by Margaret

I have an Argo AZV 244P Zone Valve Control unit and Honeywll Rev A 40004850-001 zone control valves. Does the signal which illuminates the red light in the Argo unit truly come from a contact closure in the Honeywell valve, confirming that the valve is in the fully open position? In the Argo wiring schematic, and inside the cover of the Honeywell zone valve, is that signal labeled "end switch"?

On 2013-01-07 by Scott

I have a four zone boiler system. The boiler will not fire for the basement zone. I have moved the zone valve to manual so it is receiving heat when other zones fire the boiler. What can I check/replace so the basement zone will fire the boiler based on its thermostat?

On 2013-01-04 by Dan

I will be adding an addition to my home. The existing portion right now has forced hot air but the new addition I will be installing base board heat (Hot Water Heat). Eventually the whole hose will be turned over to base board. The new addition is aprox 1500 to 1600 sqft and the existing is aprox 780 sqft.

What size furnace will I need? The 1st floor new addition will be lets say zone 2, the 2nd floor will be zone 3 and eventually the existing structure of the first floor will eventually be turned over to base boaseboard and made zone 1.

Will I have to start out with a smaller furnace so it don't cycle on & off to often and damage the furnace or can i buy the correct size for the entire home? I will be turning the existing over approx in a year.

On 2012-12-23 by Sarah

Great Site - I have 3 zones and the downstairs just seems to keep running (not constant but seems to be the only zone really pulling heat) and it runs even with therm. turned down. One of the other zones gets minimal and the 3rd I can't seem to get any heat to -

I'm thinking because the basement is sucking up all the power/heat. I can't get someone here over the holiday and I'm getting worried about pipes freezing in the one zone getting no heat. Can I just disconnect the valve for the basement? I know nothing about this stuff so really unsure! Can I just disconnect the wiring from the therm. to the valve?

On 2012-12-18 by (mod) -

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 .

On 2012-12-17 by RJ

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?

On 2012-12-11 by (mod) -

Scott,
Possibly if you include adjustable flow balancing valves. After all, equal length is not enough to assure even heat across 3 loops as they may rin at different levels, have a different number of turns, even run through building areas with different rates of heat loss. In sum, maybe.

On 2012-11-30 by Scott

in a water boiler system with approx. 120 ft of 3/4 in fin tube can I separate three loops into 40' sections with a manifold without zone valves and get even heat through all loops with a boiler that has a net IBR of 74K

On 2012-11-27 by (mod) -

Terri,
Please see your question and our reply in the bottom of the FAQs in the article just above.

On 2012-11-26 by Terri

i have 2 zones to my furnace basement zone works , but the zone upstairs makes noices as if its working furnace kicks on (2 mins) but no hot water going thru pipes ... Help!

On 2012-05-11 by Guy

Excellant and on point!

...

Continue reading at ZONE VALVES, HEATING or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see ZONE VALVE REPAIR FAQs-2 - more-recent zone valve troubleshooting questions & answers

Or see these

Zone Control Articles

• DISSOLVED OXYGEN DAMAGE CONTROL
• ELECTRIC MOTOR DIAGNOSTIC GUIDE to test zone valve motors themselves
• THERMOSTATS, HEATING / COOLING
• ZONE DAMPERS
• ZONE VALVES, HEATING - home
• ZONE VALVE MANUALS & WIRING INDEX - home
• ZONE VALVE SIZE vs GPM

 

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INDEX to RELATED ARTICLES: ARTICLE INDEX to HEATING BOILERS

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