Heating System Zone Valve Troubleshooting

Zone Heat Balancing Valves
Zone heats up too slowly
Zone valve repair mistakes & SNAFUs

Balance Heating Zones

Why are some of our heating zone manual valves set partly closed?

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 2018-02-22 y Alan

by (mod) - manual valve closing to balance heat delivery among different heating zones

Alan

The valves may have been set as they are to balance the heat delivery among various ares of the home.

When two or more hot water heating zones call for heat at the same time, and if one of the heated spaces is getting insufficient heat or heating too slowly while the other, usually a smaller or better-insulated space is getting heat faster than needed, partly-closing the ball valve or gate valve on the smaller or warmer zone gives more heat to the larger or cooler zone.

Using manual valves in this manner on hot water heating zones is common.

Sometimes the zone balancing valve is a large, easily -spotted control but often these flow balancing valves are small and hard to spot, as we illustrate just above and as we discuss in more detail

at HOT WATER HEAT FLOW BALANCING VALVES

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.

Where can I buy a flow balancing valve for heating zones

Where can I buy the "hot water heating zone flow balancing valve" (Jan 11, 2015) Jeff

Reply:

Jeff I'm not certain what kind of valve you're looking for but if you are definitely talking about heating zone flow control, stop by your local plumbing and heating supplier.

You'll see both small zone balancing valves like the one we show here, a Legend 3/4" S-439 zone balancing valve sold at plumbing suppliers, building suppliers, and at online vendors like zoro.com and grainger.com

and also more conventional ball or stop valves like others shown on this page.

How do I balance heat between zones

I have 2 zones, 1 to living room 1 to bedroom this is a ranch style home with manual zone adjusters only,

my question is,how do I adjust the flow to get less flow to bedrooms which I like to keep a little cooler the style I have is the type that requires a screwdriver

and I don't know if I turn only vertical/horizontal, or turn all the way in or out? (Jan 10, 2015) billy said:

Reply:

xBilly

It would help if you'd send me some sharp photos of your one valves and their controls - use the email found at our CONTACT link at page top or bottom.

Typically you close a valve by turning it clockwise to reduce flow or to stop it entirely.

For some simple flow balancing valves operated by a screwdriver turning the screwdriver slot to right angles to the piping will close the valve.

How to Fix Uneven heat among Different Heating Zones

We have zones in our home. We have discovered that in one zone the room where the thermostat is located seems to be the accurate temperature but the adjacent room is much much warmer.

Any thoughts on what the problem might be - (Apr 10, 2016) Lisa said:

Reply: here are commmon causes of variation in heat outputs from baseboards or radiators all on the same zone

Sure, Lisa. It would not be a surprise to find different rooms at different temperatures while they are nevertheless on the same heating zone. Some causes include:

1. open or closed baseboard top vents

2. dirty vs clean finned copper tubing

3. carpets blocking bottom air inlet under baseboards

4. if radiators are in use, closed vs open radiator valves or even partial air blockage of radiators (or baseboards)

5. different rates of heat loss in different rooms: windows that are open or leaky, doors that are open vs shut vs under-cut vs tightly-closing

6. and very basically: rooms that receive the heating water first in the piping loop get the hottest water.

Fix un-balanced heating in zones with zone valves

I have a Weil-McLain GV 4 boiler with an indirect water heater and three heating zones each with its own pump.

The third circuit ends up requiring heat much more often than the other two but there is significant circulation of hot water in the other two when their pumps are not running.

I would like to add Honeywell V8043E motorized valves to those two circuits to stop that flow. One of those circuits is presently controlled by a Honeywell R845A and the other by a Nix SP-81D. Both are connected to Honeywell two wire thermostats.

I’m having difficulty figuring out exactly how to wire the new V8043E valves. Any guidance would be greatly appreciated. (Nov 17, 2014) Bill A

Reply:

Bill

Indeed there can be incompatability in wiring together different types/brands of zone valves on the *same* circuit. I don't know the Nix model you cite.

When I got into this trouble I called my local heating supplier who kept an expert on staff (Dave Ferris, now retired) who could tell me - Oh yeah - just move that yellow wire over to T2.

Or check the wiring diagrams and instructions from the two manufacturers. Don't just use those pages to keep the soot off of your knees.

Equal zone pipe length is not enough to assure even heat across 3 loops

In a water boiler system with approximately 120 ft of 3/4 in of finned copper tubeing, 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? 2012-11-30 by Scott

Reply:

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 run at different levels, have a different number of turns, run through building areas with different rates of heat loss. In sum, maybe. - Daniel

Is it ok to use a ball valve as a zone balancing control on hot water heating systems?

Are Ball valves suitable for Hot water heating systems? On 2019-03-25 by Art

Answer by (mod) - types of plumbing valves for use on hot water heating zones

Art:

The suitability of a ball valve for use on hot water heating systems depends on just where it's to be used.

In particular, ball valves are intended to be used in the fully-open or fully-closed position and may not perform well or may jam or develop leaks if left partly-open or partly closed for a long time.

In comparison, stop valves and gate valves work perfectly well in a partly-open or partly-closed position.

So if the valve you are installing is to serve only as a shut-off it can be a ball valve.

But if the valve you are installing is to be used to regulate hot water flow by partly-closing the valve, such as balancing flow between two zones or sub zones, then use a gate valve.

See details at PLUMBING CONTROLS & VALVES

Slow Heat Delivery with Zone Valve Systems

Cause of long delays in hot water heating out of the radiators

What can cause long delays in my hot water heating system actually having heat coming out of the registers?

I got zone valves, Honeywell thermostats, Onrom relays, and a Taco pump.

Why is it taking so long as much as 30 minutes - On 2022-02-15 by Gene Lair

Reply by Inspectapedia Com Moderator -

@Gene Lair,

Just for clarity as we discuss this, I use the word "register" to refer to a warm air outlet - a furnace heating system - is your heat a water-to-air heating system?

Zone valves and Taco circulator pumps are, most-basically, associated with hot water heat delivered through radiators or baseboards or convectors.

So I'm guessing we have hot water heat and your radiators or baseboards are slow to warm up.

The cause of that delay could be a bad circulator pump (not running at all), a zone valve not opening, or air in the heating zone piping.

Here's a simple 7-Step Diagnostic Procedure for Slow Hot Water Heat Delivery

1. First be sure that your radiator valves are fully open. If they were closed or partly closed that could be the problem. If the valves are open then continue with step 2.
2. Go stand by the zone valve(s) at your boiler and be prepared to watch and listen
3. Ask a helper to turn one of your heating thermostats all the way up to its highest number.
   
   Start with the thermostat for the heating zone that is slow to heat up. (Remember to restore it to a reasonable setting later).
   
   Helper should shout to tell you when the thermostat is UP.
4. Watch and listen at your zone valves.
   
   The Honeywell valve, if it's opening, should make a whirring noise and if it's a new Honeywell zone valve you'll even see the little lever sticking out of one end of the valve move to the OPEN position.
   
   If no valve opens then that's the problem and your zone valve or wiring or thermostat wiring need repair.
   
   See ZONE VALVES, HEATING - repair advice
5. If the zone valve opens as it should, then when it's fully open it should turn on your circulator pump.
   
   Some circulators like older B&G models make noise or you can even see moving parts. But newer circulators like your Taco units are close to silent. So ...
6. Feel the pipes at the inlet and outlet sides of the Taco circulator. The pipe should get noticeably hotter on both sides.
   
   (Depending on the boiler temperature, the burner on your boiler may not come on until later.)
   
   If the pipes close to the outlet side of the circulator get hot then the circulator is probably running. Feel a few feet away or further for a more-accurate determination.
   
   If the circulator never starts,
   
   See COLD HEATING RADIATOR REPAIR (hot water / hydronic heat)
7. If the zone pipes are hot in the basement and the circulator is running and your radiators still are slow to get warm I suspect that you need to get rid of air in the radiators or in the heating piping.
   
   See those details at

• AIR BLEEDER VALVES
• AIR-BOUND HEATING SYSTEMS - home
• COLD HEATING RADIATOR REPAIR (hot water / hydronic heat)
  

Zone Valve Repair Mistakes & SNAFUS

After our Honeywell zone valve was replaced we had no heat

We have radiator heating through our condo. Out unit is right beside the boiler room if that matters.

I have a Honeywell zone valve that had developed a fast leak and was replaced, with no bleeding of pipe. After he left we still had no heat.

A few hours later still no heat and the zone valve was very very hot. Two days later we all of a sudden had heat, but the new zone valve was no longer hot, but it was now leaking.

Another plumber replaced the zone valve and this time when heat was turned up we heard water flow through, and there was no leaks, and the heat was working.

Again the pipe was not bled as he had no key that would fit due to what he said was age, and said he did not want to use a screwdriver as he was worried he would not be able to close it.

So two days later all of a sudden again we had no heat.

This time I ran all the water in the house for 15 mins to build up water pressure (read on net to help with moving air in a pipe) and then about an hour later we had heat, but it was more of a slow to heat feeling. But again the zone valve started leaking!

This will be the third time to call a plumber. Any help on what can be causing the valve to keep doing this would be appreciated. On 2019-02-10 by Stephanie
IMAGE LOST by older version of Clark Van Oyen’s useful Comments code - now fixed. Please re-post the image if you can. Sorry. Mod.

Reply by (mod) -

Stephanie

I am puzzled. The heating system boiler and piping loops are independent from the piping that brings water to sinks, tubs, showers, etc. So I don't understand how running water in a sink would impact the boiler.

Their only interconnection is that a heating boiler has a water feeder that allows makeup water to enter the boiler - operated by pressure or occasionally manually.
RUnning water at fixtures won't affect that control.

It does sound as if there may be air in the heating system that needs to be removed.

See AIR-BOUND HEATING SYSTEMS  - repair guide

After adding a third zone valve one of my other heating zones stopped working

I have a two zone heating system with two thermostats and one circulator. I recently added a third zone for my basement. I have not wired in the zone valve and T-stat yet for the new zone. Since adding my third (non active) zone my 2nd floor zone has stopped working.

If I manually open the valve then when the circulator starts to heat the first floor it pushes water around the second floor as well. I have tried testing voltages across terminals 1 and 2 and 2 and 3 but I get no readings either on the bad zone or the good one.

I would have expected to see 24V on at least the working zone but I don't. Why is that ?

I have checked the connections to the thermostats and transformer and all seem secure.

Also I noticed that my transformer doesn't appear to be sending out power - do I need to be there when something else tells it to send out power or is it constant. If it's constant and I have no power then how is my system working at all ?

Could it be I just fried my zone 2 thermostat, how could I test for that ?

I have bled the bad zone countless times and I am sure I have purged all of the air.

Any suggestions would be appreciated. - Will 11/13/11

Reply:

Will,

Since you never wired up the new zone valve, and presuming you did not change the existing wiring to the existing zone valves and circulator and thermostats, it does not sound like a wiring or control problem.

Therefore you need to look for a different problem.

When you open the new valve manually, IF one of the other zones is also calling for heat, then hot water will circulate through both the zone calling for heat AND the other zone valve that you opened manually.

I agree that you ought to be seeing voltage from the transformer - that's what sends power to the zone valves as well as the thermostat. I'd look for an open wire connection or a bad transformer.

Reader follow-up:

It wound up being an airlock. I just kept purging and purging and eventually got it.

I have another question. I used PEX and SharkBites for the whole system, however, the PEX I used was the type without the oxygen barrier. I’m told that this will cause my boiler to rust. What do you know about this, anything ?

I don’t want to have to get another roll of PEX with the barrier and tear out what I did if I don’t need to, On the other hand I don’t want an indoor pool.

Thanks
Will

Comment:

Will, when you added the new zone valve to the heating system piping, the operation of cutting the heat distribution piping and soldering in the new zone valve could have introduced air into the heating system.

If you didn't bleed that air out or provide an automatic air bleeder in a location that would do that for you, your system could be airbound.

To check for, diagnose, and fix that problem,

see AIRBOUND HEAT SYSTEM REPAIR by WATER FEED VALVE if you need to address this problem again.

Also see DISSOLVED OXYGEN DAMAGE CONTROL

Installing Taco zone control valves 571, 573 led to short heating cycles

I Installed two Taco zone controls 571 & 573, and now I have short heating on cycles. I never had this problem before, for 47 years. I had to replace the zone controls because the old zone valves started to stick, but they were not Taco brand. I replace the thermostat with a Honeywell TH3000 series, but that didn't solve the problem. - Anon

Reply:

Anon,

When the thermostat calls for heat the zone valve opens and the circulator starts pumping. It is the temperature of the water in the boiler that turns the burner on and off. By short cycling I presume you're meaning that the boiler stays on for just a short time, turns off, then quickly turns back on.

Sometimes this is a normal event, for example when the first surge of cold water from zone 1 hits the boiler and turns it on, the boiler's burner may be able to heat up the boiler quickly and shut it off; the boiler would stay off for a while.

But when zone 2 then opens and sends a new surge of cold water into the boiler it will start again quickly in response to that new temperature drop.

However, because it normally takes some time for the heating zones to actually satisfy the thermostat, once both zones are running your boiler should return to normal run times. If it doesn't I suspect a sensor or control problem at the boiler.

How to fix a backwards-facing zone valve

Added another V8043 zone valve to existing radiant system but installed it opposite the designated flow direction. Will I be in trouble if I leave it as is. (Nov 3, 2014) billjankski@gmail.com

Reply:

Yes. I'd remove the valve and install it in the proper direction.

Zone valve is working backwards: opens when we don't want heat and closes when we do

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 2017-10-29 by AJay

Answer 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.

How to Use only one zone valve in a 3 story, 6 unit apt building

I have been told of a method of putting in only one zone valve in a 3 story, 6 unit apt building with baseboard heaters and an oil-burning boiler.

The plumber is originally from Europe and he says all I have to do is set a thermostat on the bottom of the first floor (coldest spot) and set the zone valve to the mandatory 68 degrees.

There are technically 3 zones because the heaters on each floor are all connected.

But to avoid the expense of installing 3 zone valves, this guy said that if I put the thermostat on the 1st floor, when any apt calls for heat it will open and run through the baseboard heaters of all - up to 68 degrees.

Then the valve shuts off and the upper apts rely on the heat rising from the lower floors.

Does anyone know about this method, and does it work? On 2019-06-09 by Kay

by (mod) -

That sounds like a highly questionable idea. You can't take a generic statement like that in as soon as going to work in every building.

Furthermore in Europe where you are expert comes from that installation would be illegal. Either you're going to give each tenant control over their level of heat or you're not.

And most buildings we nearest one zone and multiple apartments on multiple floors some of the people are going to always be unhappy and are going to complain of either being too hot or too cold.

There are other options discussed in this article series such as using thermostatic radiator valves that can make each radiator its own little Zone.

The idea of having one zone valve doesn't seem sensible to me in the first place if there's only one zone you wouldn't need a zone valve.