FAQs about fixing zone valves on hot water heating systems - set #3.

This article series explains what zone valves are, how they work, where they're installed, and how to troubleshoot and repair them.

FAQs on Zone Valves - 3

These hot water heating zone valve questions & answers were posted originally at ZONE VALVES, HEATING - you will enjoy reviewing the advice given there.

On 2018-06-30 by (mod) - electrical wiring for zone valves - amateur can mean trouble

Judy

I prefer to stay out of what my mother called "a lot of who-struck-john" arguments where people stand in a circle and point blame on the next person to their right.

But in my OPINION, I would prefer to have a licensed electrician do electrical wiring and a plumber do plumbing.

You need to find a different electrician, one who is familiar with wiring radiant heating systems, thermostats, zones, controllers, or who will at least read the instructions in the installation and operation manual for your heating system and each of its controls - be sure that your installer left those with you - and talk to the heating company directly if needed.

On 2018-06-30 by Judy

We're building a small house with 3 zone radiant heat. The plumber said it is all ready to go except for the wiring and to call the electrician.

The electrician says they don't do that wiring anymore...the plumber should do it. Who do I believe?

On 2018-04-12 by (mod) - put zone valves on the cooler return side of the heating loop

Ron

Zone valves will work properly on either supply or return side of the system, but in my OPINION and that of many service techs, installing the zone valve on the return side is preferable since the valve then operates at a lower temperature and has a longer life.

You'll find that recommendation in typical instructions for zone valves as well.

On 2018-04-12 by Ron

In a residential hot water (radiators) system are the zone valves installed on the supply or return side of the boiler. Does it make a difference?

On 2018-03-31 by Clarence Cook

I have a multi-zone system with a single grundfos circulator. All zones are calling for heat but the circulator does not come on until the water temp falls enough for the furnace to start. As soon as the water temp reaches 190, it, and the circulator stops. The zones are still calling for heat to no avail. All lights are lit in the two argos calling for water and all zones are open. Any ideas? Thanks

On 2018-03-03 by Randy

I have replaced the b&g pumps series 100 with Honeywell 3 speed pumps because I get a lot of water fall noise in the pipes. The flow valves probably have never been touched. I have been bleeding air from baseboards for days and still have lots more (air bubbles) any suggestions thx

On 2018-03-03 20:41:37.278748 by Randy

I have a system built in the 60’s boiler replaced in 2010 one floor,2 thermostats and 2 circ pumps. 2 returns and 1 supply. I don’t see any zone valves I see 3 b&g flow control valves. What am I missing?

On 2018-02-22 22:44:13.153726 by (mod) -

Alan

The valves may have been set as they are to balance the heat delivery among various ares of the home. You can of course experiment with changing them as your needs could be different from those of prior occupants.

Insulating heating pipes improves system efficiency but watch out in a new-to-you house: don't insulate heating pipes if they're being used to provide heat at some otherwise un-heated space harboring water pipes that could freeze.

On 2018-02-22 22:44:12.094305 by (mod) -

Alan

The valves may have been set as they are to balance the heat delivery among various ares of the home. You can of course experiment with changing them as your needs could be different from those of prior occupants.

Insulating heating pipes improves system efficiency but watch out in a new-to-you house: don't insulate heating pipes if they're being used to provide heat at some otherwise un-heated space harboring water pipes that could freeze.

On 2018-02-22 22:11:36.200633 by Alan

Hello. This may be a bit off topic but help would be appreciated. We have moved into our "new" home" (18 years old) about 4 months ago, and I noticed that the ball valves for the 3 zones of the hot water heating system are set at approximately 1/2 way open (or closed). Is this the correct setting or should I open them fully?

1 zone, the finished lower level, is particularly slow in warming up when my wife wants to go downstairs to sew. Would opening the valve fully allow for more rapid heating?

Also, should the heating copper pipes be insulated? We hired a company to do "complete insulation work" but they did not do those copper pipes; only the hot water supply for domestic use. Thanks so much. alanmglasser@gmail.com

On 2018-02-12 22:46:52.285666 by (mod) -

James

I'd Use the on-page search box at the top or bottom of this page to find the diagnostic article on BANGING HEATING PIPES and also the article on WATER HAMMER - as those offer detailed diagnostic and repair suggestions.

On 2018-02-09 14:14:58.289544 by James O'Grady

I have been having problems with my firsy floor heating zone. I have a slant fin gas hot water baseboard system.

When the first floor called for heat the boiler would short cycle. I also would getting banging pipes. I have changed the thermostat the expansion tank and know the zone valve and bled the lines of air.

The boiler turn on and ran when the first floor zone called for heat and it seem that what i did solved the problem.

But 8 hours later I once again had banging pipes all the way up to the second floor zone. What esle could be wrong with this system

On 2017-12-10 03:44:44.796004 by (mod) -

Gene, with six zone valves are we blowing the low voltage transformer? I'd add a 2nd one and split the work 3 & 3 on each transformer.

I'm the same age (almost) as you so I can be frank. The contractor is a dope. There is almost never a "blueprint" for thermostat wiring, in fact even the word "blueprint" is wrong - it'd be a wiring diagram.

But any service tech who is worth the cost of the gasoline to drive to your home knows how to follow the damn wires.

On the other hand, when we're dead we won't be cold. I'm more worried about when you're too old to follow your own wires, but not dead, and you're cold and your contractor is too - whatever- to follow the wires to fix a bad connection or relay.

Anyway Gene your previous questions and our discussion are below on this page among comments, and will also be found at

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

On 2017-12-10 by Gene 12/9/17

I have 6 zone valves and 3 small Taco pumps 2 zones for each pump and 6 thermostats I was using 4 zones and it worked very well I added 2 more zone valves and I have been making this for a few years and when I had to replace the trans former I had all theses pairs of wires at the transformer by adding the a pair at a time .

I had a heating contractor came out and he ask for a blue print I said there was none so since I am 76 years old if I was to dye they would want to tear out all of this that would be a bad idea I know it has worked great I just need to get it going again. Any help would be appreciated Thank You.

On 2017-12-10 by (mod) -

Carl:

In a typical 24VAC system with just a few zones each thermostat talks to a zone valve (assuming you're using zone valves) or else to a circulator relay (if you have one circulator for each zone)

Where there are 5 zones you might look at a multiple-zone controller like the the controls we discuss at ZONE VALVE WIRING https://inspectapedia.com/heat/Zone_Valve_Wiring.php

On 2017-12-10 by (mod) -

Gene I'm not sure I understand the question. If by "keep this" you mean this article series, just bookmark it.

To wire 6 zones you probably want a pair of multi-xone controllers as your note suggests.

On 2017-12-10 by Gene 12/9/17

Hydronic heating need wiring 6 zone valves V8043F with Omron relay G 2R-S 24 volt to 3 small 110 volt Taco pumps wiring how can I keep this to come back to for later ?? Each pump has 2 zones

On 2017-12-09 by carl

hi all, we just moved into a house and are trying to figure out the wiring for the 5-zone hot water baseboard heat.

The system uses 120V line level thermostats for each zone, and I'm trying to plan to replace with 24v and relays connecting the 24v to the 120v sections.

I see how this would work for single zone, but what's difficult to figure out is how each of the thermostats connects back the the boiler and valves for each zone. The wiring is spaghetti since it's using romex and mixed in with all of the normal 120v lines.

should I expect each thermostat to run back to the valve? do they all have to run to the boiler as well? Any links to wiring diagrams for these multi-zone setups with line level thermostats would be helpful- they seem really uncommon,

On 2017-12-09 by (mod) -

Heating boiler water hammer noise tip for readers:

Water hammer, discussed in general

at WATER HAMMER NOISE DIAGNOSE & CURE

can occur in both building potable water supply systems (sinks, tubs, showers) and also in hot water heating systems as well as at water heaters or calorifiers.

At water heating equipment water hammer risks an additional hazard besides noise: water hammer can cause leaks at the temperature/pressure relief valve. And over time a relief valve that leaks can also clog from mineral deposits and - to put it technically - crud on the valve seat.

A clogged relief valve means that the heating equipment is unsafe to operate, risking a BLEVE (search InspectApedia.com for BLEVE Explosions for details)

If your heating system is giving a loud BANG when the zone valves open or close (and circulator starts or stops) take a look at the location of the zone valves. Good practice locates the zone controls and circulators on the return side of the hydronic heating loop. There's theory that the slightly lower temperatures give longer component life and that this location will reduce water hammer noise in the heating zones.

by locating the circulator downstream from the return-side zone valves - that is, between the zone controls and the boiler, the impact of the pump start-up on the zone valve is reduced.

If you continue to have annoying water hammer banging when the circulator pump starts (or stops) consider changing out your zone valves to a slow closing valve such as the Taco #570.

On 2017-11-30 by (mod) -

Gene,

I don't know to what your yellow and blue leads are connected. But I'm guessing you refer to zone valve wires.
The thermostat has to be calling for heat, the you should see voltage at the zone valve.

On 2017-11-30 by Gene

I put on a new 24 volt transfomer and with test leads it shows 24 volts but then I connect leads on yellow and blue leads and it shows no current why ?

On 2017-11-21 by (mod) - zone valves can sometimes be hidden

Dave

Annoyingly, zone valves can sometimes be hidden enroute on the heat piping between boiler and a specific building area, but usually they are very close to the heating boiler itself, usually on the return side. Take a look at your boiler, follow the heat piping coming into it.

On 2017-11-21 by Dave

my kitchen, bathroom and family room run off a different zone than the rest of the house and is not currently producing heat(gas) I replaced the thermostat with negative results. Now I hear it might be the zone valve, where do I find the valve and how do I replace it

On 2017-10-29 by (mod) -

AJ

Is this a brand new zone valve just installed? If so perhaps it's the wrong model - there are valves that work in just the way yours is described.

If it is an old valve with a new problem I suspect that its wires are shorted, reversed, or the control head circuit has failed.

But the fact that you found valves installed backwards is a tipoff that someone who was not an expert has been installing heating parts, so she or he may have also selected the wrong type of zone valve or may have crossed wires.

On 2017-10-29 by AJay

I have a zone valve that is doing the exact opposite of what it is suppose to be doing, when the thermostat kick on the valve closes and we dont get heatn when the thermostat is off, it opens and the room gets hot... Why is it doing this?

I work at a hotel and each room is individually zoned. We have baseboard heating. I onbly have 3 rooms that this is the problem in. We have chnge 2 valves that were put in backward but that did not fix the open and closing issue.

On 2017-07-15 by (mod) -

Rob

I'm confused too. Normally I'd expect to see just one zone valve - used to heat water in an indirect-fired water heater system; but

Perhaps the second zone valve is on a hot water circulating system that provides instant hot water at all fixtures.

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?

Question:

(Mar 1, 2015) kevin said:
just replaced thermostat zone calling for heat base board are cold still

Reply:

HEAT WON'T TURN ON in More Reading - ARTICLE INDEX (above)

or the air bound heating system repair at

inspectapedia.com/heat/Air_Removal_2.htm

may help you out - assuming your boiler is running.

I suspect your system is air bound.

Question:

(May 7, 2015) Anonymous said:
Baseboard rad line busted.lost glycol.how do I get air out of system

Reply:

Anon

see the step by step procedure at

inspectapedia.com/heat/Air_Bound_Heating_System.php

Reader question on stuck zone valve: V8043D1205/U

(July 20, 2015) Robert said:
I have a normally open honeywell zone valve with 24VAC, 5W, 6RPM output motor actuator. The valve closes on when energized.

The model is V8043D1205/U. The thermostat is reverse acting. Now, if we turn down the thermostat, the thermostat will send 24VAC to the valve motor and the motor will operate to close the valve.

The valve will usually close in 10-15 sec, but it may take few minutes to reach the set temperature. That means there will be a period when the valve is fully closed but there is still power to the motor from the thermostat - until the set temp is reached. So, once the valve closes fully, what happens next ?

Will the motor keep operating / turning trying to close the already closed valve and damage the gear assembly and also causing overheat in motor that will burn the motor ?? Is there any mechanism inside to stop motor turning the gears once the valve reaches full close position and there is still power to the motor ?? Otherwise damage will result ??

Reply:

Yep you may need to replace the motor or the whole valve;

Question: why are some zones too hot when the thermostats are not calling for heat

1 Nov 2015 Kerry said:

I have a 14zone HWBB system installed during home construction 8years ago. Each room has its own loop and thermostat. I have zones that are hot 10-15 degrees above set points. All check valves were replaced 10/15/15. System worked fine until spring 2015. When I noticed the hot zones

Sorry, I guess my question from yesterday should have been , why are these zones so hot when the thermostats are not calling for heat? Water is somehow bypassing the check valves, which is why I had them replaced. Any thoughts out there?

Reply:

Kerry:

I suspect that the flow-control check valve at the hot water lines exiting the boiler is either in manual "open" mode or is stuck open.

Also check that the thermostat wires are not shorted together.

Question: many VA transformer do you need to power 4 zone valves

1 Nov 2015 Dennis Santoro said:
How many VA transformer do you need to power 4 zone valves

Reply:

One should do it.

See LOW VOLTAGE TRANSFORMER TEST where you'll find articles about installing and wiring and repairing low voltage transformers.

More help is also at THERMOSTATS, HEATING / COOLING - home and the thermostat wiring articles.

...

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

Or see ZONE VALVE REPAIR FAQs-4 - more-recent diagnostic questions and answers about zone valve repairs.

Or see these

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  • ZONE VALVE MANUALS & WIRING INDEX
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  • ZONE VALVE BANGING or BACKWARDS
• ZONE VALVE BANGING or BACKWARDS
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• ZONE VALVE MANUALS & WIRING INDEX

Suggested citation for this web page

ZONE VALVE REPAIR FAQs-3 at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to HEATING SYSTEMS

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