Heat getting to wrong zone somehow...

Reply

  #1  
Old 12-19-10, 11:08 AM
Member
Thread Starter
Join Date: Apr 2010
Location: US
Posts: 16
Received 0 Votes on 0 Posts
Heat getting to wrong zone somehow...

Hey guys...

I have 2 story 100 year old home.

A small addition was put on the back of the house at some point.

The original section of the house has all cast iron radiators on the first and second floor. The radiators run in a paralell circuit.

The addition is the same level as the first floor and has slant fin baseboards in series.

The old section of the house is one zone and the new section is the other for a total of two zones.

The zones are controlled with a Taco 573 on the original section of the house and 571 on the addition.

The boiler controller and zone valves to seem to be working correctly. Both zone valves and the controller are new.

The issue is that when the baseboard section is calling for heat... after some time goes by the wrong zone is getting very warm. Some of the radiators are getting very hot. The zone with the baseboard does not meet the desired temp on really cold days. But the old zone is exceeeding the desired temp.

Bascially... out of 6 cast iron radiators... about 3 are getting hot when there should be no heat going to that zone. Hot water is getting to the wrong zone and being wasted.

The zone valves are installed on the return side of the system. I do not see any other type of flow control devices on the supply or return plumbing.

Do I need some type of check valves? How do they work and is there a thread on how to install them?

Should I move the zone valves to the supply side?

Any ideas or suggestions?

Thanks
Eric
 
Sponsored Links
  #2  
Old 12-19-10, 12:49 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: Galivants Ferry SC USA
Posts: 18,017
Received 41 Votes on 36 Posts
What is the make and model boiler?

What is the boiler temp and pressure?

The zone valve may be stuck open slightly from corrosion in the body.

Did you replace the whole zone valve or just the heads?

How recent was this?

Could they of been wired incorrectly and wires crossed?

Are the zone valves set to auto? Manual?

Take pics.

Mike NJ
 
  #3  
Old 12-19-10, 07:14 PM
Member
Thread Starter
Join Date: Apr 2010
Location: US
Posts: 16
Received 0 Votes on 0 Posts
Peerless Boiler Model# MI-05-STDG-WPG

Aquastat controller set to 180... 20 psi....

Corrosion or an internal leak was my guess on the 573 cause it was old.

On the 573 I only replaced the head and the "guts".. I bought a new 573 and replaced the insides so I would not have to solder. I did take some emery and cleaned the sealing surfaces in the old body. Did this yesterday.

The 571 is completely new... replaced in April cause it was leaking.

The valves are set to "Auto"

The valves do function correctly. I have double checked the wiring and it is correct.

This only happens when the smaller zone calls for heat for an extended period of time without ever being satisfied.... over 2 hours... it is like the system is "bleeding" to the wrong zone somehow.

If I pull the lever down on the 573 when it is not calling for heat I hear the water start rushing... so I assume it is doing its job somewhat.









 
  #4  
Old 12-19-10, 08:40 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 14,090
Received 15 Votes on 13 Posts
Has the system ever worked properly?
When only the basboard zone is calling for heat, does the pipe upstream of the radiator zone valve get hot?
 
  #5  
Old 12-20-10, 06:35 AM
Member
Thread Starter
Join Date: Apr 2010
Location: US
Posts: 16
Received 0 Votes on 0 Posts
Originally Posted by Grady View Post
Has the system ever worked properly?
I don't think so.

I have only lived here since last January. The heating system had multiple issues.

List of faulty components includes (in order of replacement)

Pressure Relief Valve
Expansion Tank
Aquastat
571 Zone Valve
573 Zone Valve

It finally seems as though components are turning on and off the way they should... but we now might be in to a design problem.

It is much... much better then it was but still not %100 correct IMO.


Originally Posted by Grady View Post
When only the basboard zone is calling for heat, does the pipe upstream of the radiator zone valve get hot?
Yes... the 573 and the pipes leading to it get almost as hot as the zone that is open.

If you guys have any suggestions please let me know... I am willing to install or rearrange anything just to get this working the way it should.
 
  #6  
Old 12-20-10, 08:39 AM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: Galivants Ferry SC USA
Posts: 18,017
Received 41 Votes on 36 Posts
Well from you posts I would say you need to take the 573 apart and see whats in there. If you changed the valve and seat, powerhead its basically a new unit.

As far as only three radiators getting hot, the others should have a bleeder valve, and most likely are air bound.

As far as the baseboad not meeting expectations on a cold day... 100 yr old house I would say too many drafts from old windows? Not enough element?

Here is a link. It has a internal diagram of a zone valve that might help. Page 3

http://www.taco-hvac.com/uploads/Fil...ValveBroch.pdf
 
  #7  
Old 12-20-10, 09:51 AM
Member
Thread Starter
Join Date: Apr 2010
Location: US
Posts: 16
Received 0 Votes on 0 Posts
I think I might be confusing you a little... maybe throwing too much info out there.

Originally Posted by lawrosa View Post
Well from you posts I would say you need to take the 573 apart and see whats in there. If you changed the valve and seat, powerhead its basically a new unit.
As in pop it apart and check for debris?

Originally Posted by lawrosa View Post
As far as only three radiators getting hot, the others should have a bleeder valve, and most likely are air bound.
3 out of 6 radiators get hot in the 573 (Cast Iron Radiator) zone when the 571 (Baseboard) zone is calling for heat. This is what I want to concentrate on fixing right now. I would think that if the 571 zone is calling for heat that zone alone should get hot... not any part of the 573 zone.

When the main part of the house calls for heat (573 zone) the desired temp is met just fine.



Originally Posted by lawrosa View Post
As far as the baseboad not meeting expectations on a cold day... 100 yr old house I would say too many drafts from old windows? Not enough element?
Yes... there might not be enough element. The addition is newer construction... not too drafty but it is over a unheated crawl space. This issue I will address after the zones are isolated from each other. Unless you think I am going about this the wrong way?

The most important thing to me right now is isolating the 2 zones.

Since the valves are on the return side... hot water is allowed to mix with water in zones not calling for heat to a point. Could this lead to hot water rising and cold water pushing down through the 573?

I was wondering if putting the zone valves in the supply side then a flow check close to the end of the return on the 573 zone might work.... opinions?


Thanks for your help guys....
 

Last edited by DPR250R; 12-20-10 at 10:54 AM.
  #8  
Old 12-20-10, 03:28 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
The most important thing to me right now is isolating the 2 zones.
So let's focus on that, do some diagnosis, and not get sidetracked...

My gut feel is ghost flow... but let's review a few things said first:

Grady: When only the basboard zone is calling for heat, does the pipe upstream of the radiator zone valve get hot?

DPR: Yes... the 573 and the pipes leading to it get almost as hot as the zone that is open.
And I ask: The pipes on BOTH sides of the valve get hot? Since the valves are on the return, UPSTREAM refers to the RADIATOR side of the valve, not the boiler.

FOLLOW THE HEAT... Start at the 573 valve and handle the pipe all the way as far as you can... is it hot all the way to where it comes into the basement?

Do the same on the supply side.

Tell us what you find.

3 out of 6 radiators get hot in the 573 (Cast Iron Radiator) zone
Which three? The FIRST three off the hot supply side? or what?

Don't go rippin' the valve apart again just yet.
 
  #9  
Old 12-20-10, 05:18 PM
Member
Join Date: Nov 2010
Location: USA
Posts: 123
Received 0 Votes on 0 Posts
In looking at your pics..
You have 2 thermostats in 2 different areas, correct?
I only see 1 thermostat wire entering the Aquastat box.

Does your Aquastat have 2 separate thermostat input wire pairs, or are they wired together (parallel)?

It looks like (from the pics) both zone valves are wired together, so either thermostat call operates both zone valves.
 
  #10  
Old 12-21-10, 06:35 AM
Member
Thread Starter
Join Date: Apr 2010
Location: US
Posts: 16
Received 0 Votes on 0 Posts
@Trooper.... OK... sounds like a good plan to me. I assume I should wait til the system is cooled down and see what parts get warm first. Thanks for the upstream clarification... and yes... the pipe on the radiator side gets very warm if not hot when it is not supposed to.

@Thomas... the wire you see actually has 4 leads in it (White, Green, Red, Black). The valves and Aquastat are wired per this diagram. I edited it a little to match my system. At home I printed this pic and color coded the diagram to make sure everything is correct. I have also double checked the valves while working with a voltmeter and by pulling the manual lever/checking for resistance.

Thanks for your input... because sometimes the answer is right in front of you and getting a couple different opinons is always good IMO.

 
  #11  
Old 12-21-10, 04:39 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
3 out of 6 radiators get hot in the 573 (Cast Iron Radiator) zone
Which three? The FIRST three off the hot supply side? or what?
 
  #12  
Old 12-22-10, 12:18 PM
Member
Thread Starter
Join Date: Apr 2010
Location: US
Posts: 16
Received 0 Votes on 0 Posts
Originally Posted by NJ Trooper View Post
Which three? The FIRST three off the hot supply side? or what?
Ok... this is going to be hard to explain. Without a diagram or being able to point to the pipes.

I followed the heat with only the 571 zone on. Disregard what I said in response to Grady before about the return side of the 573 zone.

The highest branch of the 573 supply side gets warm first. Then the return of that branch gets warm and then heat seems to flow across the "T" where the 2 573 branches meet then backwards up the return side of the other branch of the 573 zone.

Thoughts? Should I try to mark up the photos I posted?

I was thinking that since the circulator is on the return side that I should mount the zone valves on the supply and a check valve on the 573 return.
 
  #13  
Old 12-22-10, 05:20 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
The radiators run in a paralell circuit.
You mean that there is a SUPPLY and RETURN that go to each of these rads, right?
TWO PIPES?
 
  #14  
Old 12-22-10, 06:50 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 14,090
Received 15 Votes on 13 Posts
Do both of the pipes going to the rads come off the same main?
 
  #15  
Old 12-23-10, 06:49 AM
Member
Thread Starter
Join Date: Apr 2010
Location: US
Posts: 16
Received 0 Votes on 0 Posts
@ Trooper.... yes... each of the radiators has a supply and return. Like this wiring diagram... imagine the speakers represent the radiators.



Originally Posted by Grady View Post
Do both of the pipes going to the rads come off the same main?
I think so... The 1 1/4" pipe you see gets split off in to 2 sections of the house. Each supplies 3 radiators. Does this diagram help?... apologize for my lack of graphic design skills.



Here is the order of pipes getting warm.

 
  #16  
Old 12-23-10, 08:53 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
Your graphic skills are par excellence! I believe that this has helped me to understand what's happening... and 'ghost flow' it is...

Hard to explain what I'm thinking... but one fact is key... water will always flow from higher pressure to lower pressure.

Without going into a lot of detail as to how/why, etc, let me just say that I believe that the solution will be to install a single check valve in the return pipe that you have labeled as 3 <--- in your photo above. That check valve needs to be installed there to prevent the reverse circulation in that branch. At the same time, it will prevent the forward circulation in the other radiator branch.

It should also increase flow in the intended zone...
 
  #17  
Old 12-23-10, 11:52 AM
Member
Thread Starter
Join Date: Apr 2010
Location: US
Posts: 16
Received 0 Votes on 0 Posts
Ok Trooper... sounds good! much easier then my plans to tear it all apart and start over....

I don't know when I will get a chance to do this because money is tight and I get intimidated draining the system in the middle of winter... but this does need to get addressed.

Once again... a big thanks to you Trooper and everyone that contributed!! I went from knowing NOTHING about heating to at least getting some of the basics down.

Will report back when the job is complete!!!
 
  #18  
Old 12-23-10, 04:11 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
DPR, please understand that this is based on what I know of your system, and how it is behaving... it's not a 100% diagnosis! You might put that valve in and have it not cure the problem... but I am pretty sure it will. Just so you know that... I wouldn't want ya cursin' me out after going to the trouble. So... please use this info at your own risk.

I'm wondering... in the 'sequence of heating' pic with the arrows... #3 gets warm after #2 obviously... but if there were to be a #4, where would it be?

In other words, if the other zone was heating for long enough, would you feel the supply line to the radiator loop to the left start to heat up? If you can convince me, and yourself, that you do indeed have reverse flow in that loop to the left in the pics, then my diagnosis is almost certainly correct...

Points to know when installing check valve:

You want to install that check valve in a straight section of pipe, as far from an elbow as possible. Too close to an elbow and you will have a turbulent flow that can cause the check to make a very annoying rattling noise.

I believe that the check will have the same effect if it were installed in the supply pipe to the left ... the one I think will be #4 in the above (below) pic. This might also make it easier to get a good length of straight pipe upstream of the check valve.

If you've got it apart to install the check, you could also install a FULL PORT ball valve in the pipe at that point as well. It never hurts to have valves installed to isolate parts of the system in the event that service needs to be done.

Price ain't too bad...
SC125S - Hydrovalve SC125S - 1-1/4" Solder Ends Swing Check Valve

The pic shows threaded, but the description shows solder ends:
750C06 - Matco-Norca 750C06 - 1-1/4" Full Port Solder Ends Ball Valve

I agree that dead-o-winter might not be the best time to tackle this, and if you don't have experience soldering copper keep in mind that 1-1/4" takes a good hot torch... and some practice.
 
  #19  
Old 12-27-10, 12:00 PM
Member
Thread Starter
Join Date: Apr 2010
Location: US
Posts: 16
Received 0 Votes on 0 Posts
No worries trooper... I would not curse anyone out here after offering help. I realize in the end I have to decide what I think is best for the system and proceed on my own.

Wow.. those are the check valves I need?

SC125S - Hydrovalve SC125S - 1-1/4" Solder Ends Swing Check Valve

I was thinking I needed the Taco Flo-Checks @ $45 each... that is pretty cool.

I wanted to install a check valve on both 1-1/4" returns... since I wil have it apart. Would you advise against that for any reason?

Can you give me a minimum measurement of about how far back from the elbows the check valves need to be to avoid noise? I don't really have too much room.

I was hoping to tackle this on Friday or Satuday cause the temps look like they will be in the 40's. I am OK at soldering... def not a pro. I bought a mapp torch because the 573 valve was installed backwards and I had to turn it around. The propane torch would not do the job.
 
  #20  
Old 12-28-10, 03:17 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
Sorry for being 'sidetracked' for a few days with this damn blizzard...

You could use the Taco also. I can't think of a reason not to use these... unless someone else chimes in with a good reason, I would say go ahead and save a few bucks.

I don't think you need them on both. The way I think the flow is occurring you would only need the one... and you could put it on the supply pipe as I mentioned...

BUT, first do the test I mentioned... continue to follow the heat... see if the SUPPLY side for the rad loop to the left eventually gets hot. This will confirm what I'm thinking might be happening.

Install as far from the elbow as you can, I would say a minimum of 12".

Just remember, one little drop of water in a solder joint is gonna mess ya up bad... so make sure all the water is out!
 
  #21  
Old 01-02-11, 09:46 AM
Member
Thread Starter
Join Date: Apr 2010
Location: US
Posts: 16
Received 0 Votes on 0 Posts
Success!!!

First... I did have trouble with the install. On assembly the first shut off valve I tried to install I could not get the solder to flow in the joint. It kept coming out and beading up. After multiple attempts I started to panic and called my buddy who taught me how to sweat pipes.

We installed the two check valves and shutoffs linked below... one shutoff started to leak (cause I overheated it) so we had to take it off and replace it with plain pipe.

I started at 9am and finished at 5pm on Friday... it was a long day. But totally worth it. I tested it all day yesterday... Had just the 571 zone all day with the 573 zone staying cold the whole time!!!

I am done for a while messing with this thing but I might be back in the spring about splitting the main part of the house in to 2 zones....

Big thank you to you Trooper and everyone else that helped out!!!
 
  #22  
Old 01-02-11, 10:38 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
We installed the two check valves and shutoffs linked below
I don't see no links? did you post pics to the new stuff you installed?
 
  #23  
Old 01-02-11, 12:33 PM
Member
Thread Starter
Join Date: Apr 2010
Location: US
Posts: 16
Received 0 Votes on 0 Posts
Originally Posted by NJ Trooper View Post
I don't see no links? did you post pics to the new stuff you installed?
I meant the stuff from Pex you had linked...

Here are some pics... these are from my phone so they are not great.





I tried to get them as far from elbows as possible while still making the accessible.

I have heard no noise from them at all.... thanks for pointing those out as an option... saved me $80 or so!!
 
  #24  
Old 01-02-11, 03:37 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
Looks good... see what I mean about soldering the bigger size pipe? It do get much more difficult once you get over the 3/4" size. That's when the 'B tank' torch really starts to come in handy.
 
  #25  
Old 01-02-11, 06:03 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 14,090
Received 15 Votes on 13 Posts
Yep, thems some good lookin' joints. Somebody knows how to solder. No stalactites hanging from the fittings. Good Job.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: