Help with zone heat problem

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  #1  
Old 01-08-14, 06:08 PM
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Help with zone heat problem

Hey NJ Trooper - you seem to be really good on this subject so I'm coming straight to you... sort of haha.

This same thing in this thread happened to me.

http://www.doityourself.com/forum/bo...t-problem.html

I followed along with all of your instructions and now the pressure is back up where is should be in my boiler!

The only problem is that one of my zones, the one that mad me realize there was a problem, still doesn't work. I've gone through and purged all the baseboards. There are four baseboards in this zone. 2 of them have perfect water flowing through them and the air is gone. However, the other 2 seem to have no water at all coming out of them when I try to purge them!

Any idea why two baseboards would have water when the other two on the same zone don't appear to want to let me purge them?

Quick help is much appreciated!
 

Last edited by lawrosa; 01-09-14 at 06:18 AM.
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  #2  
Old 01-08-14, 06:25 PM
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Any idea why two baseboards would have water when the other two on the same zone don't appear to want to let me purge them?
Welllllllllllllllll.................

Given the rash of frozen pipes lately, I would say that Ol' Man Winter has visited your home.
 
  #3  
Old 01-08-14, 06:32 PM
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I suppose that is a possibility... but, the order that the water flows is like this...

Source > baseboard with water pressure > baseboard without water pressure > baseboard with water pressure > baseboard without water pressure > back to source

None of them are hot, but everything from the circulator to the zone valve to the wall is very hot.
 
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Old 01-08-14, 06:35 PM
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Strange...

How are the baseboard piped? Is it possible that they are not in 'series', but on what are called 'monoflo' tees?

Can you take some pics of the piping?
 
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Old 01-08-14, 06:41 PM
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You raise a good point. That may be the case. Unfortunately, all the piping is under the floor so I'm unable to see it.

I was told previously that they were on a series, but it's possible that person was incorrect.

The thing that is baffling me (supposing that they are monoflo) is why there seems to be pressure and no heat when I'm positive that there is heat coming from the zone valve.
 
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Old 01-08-14, 06:50 PM
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Yes, something isn't making any sense!

None of them are hot, but everything from the circulator to the zone valve to the wall is very hot.
How about the other end of the loop, at the return to the boiler? Is that hot too?
 
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Old 01-08-14, 07:03 PM
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How about the other end of the loop, at the return to the boiler? Is that hot too?
It sure is. That was one of the first things I checked last night when I noticed the problem.
 
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Old 01-08-14, 07:14 PM
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Unfortunately, all the piping is under the floor so I'm unable to see it.
You don't mean in a concrete slab, but rather a wood frame structure... and there's a finished ceiling concealing the piping?

It sure is
Well... in that case... it _could_ be monoflo and the main line is flowing...

but on two of the rads BOTH the supply and return could be froze,

and on the two that you are getting water out, only the supply OR the return are froze. So if only one is flowing, you would still get flow out the bleeder, but no flow THROUGH the radiator, from supply to return.

On the two that you were able to bleed, did you eventually get hot water out the bleeder?
 
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Old 01-08-14, 07:21 PM
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You don't mean in a concrete slab, but rather a wood frame structure... and there's a finished ceiling concealing the piping?
It's not in a slab... it's between the floor and the slab. My house has a weird history that is tough to explain. There are various points where I can access under the floor and feel that the pipes are warmer. However, I can't see/feel them all. I'm leaning a little more towards the realization they might be frozen, but I'm still not thinking that's the most likely thing.

did you eventually get hot water out the bleeder
Nope. But then again I may not have run them long enough for that to happen. Any suggestions on how long that should take?
 
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Old 01-08-14, 07:31 PM
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it's between the floor and the slab
So I think you are saying that it's possible it could get pretty cold under the floor then?

I'm leaning a little more towards the realization they might be frozen, but I'm still not thinking that's the most likely thing.
Let's recap:

It's fairly safe to assume that they aren't piped in series I think. If they were, the scenario you describe is an impossibility. (or the bleeders are clogged?) You certainly could not have no flow in rads on either side of one that you did have flow in.

So, let's say they almost _have_ to be monoflo, because for the supply and the return to be HOT, you must have flow.

They can't be direct or reverse return because in order to have flow at least ONE of the rads would have to be HOT.

Freezing and monoflo is the only way I can envision what you describe is happening................

Has the heat been on continuously in that zone? or was it shut off for a time? maybe you also run a wood stove and the boiler wasn't called for heat for some time? (common problem with pipes freezing!)
 
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Old 01-08-14, 07:43 PM
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So I think you are saying that it's possible it could get pretty cold under the floor then?
I suppose it could be possible. But it doesn't seem to be the case. I won't rule it out though.

Has the heat been on continuously in that zone?
Yep. The boiler has been on since it got cold enough out to turn it on and the baseboards ran for quite a few months until about 36-48 hours. Which sadly (I'm slowly coming to the realization things may be frozen) is when the temperature dropped WAY down. Now my problem is figuring out how to thaw it out (or maybe I'll just have to wait until the temp goes up outside)

I agree that it must be monoflo. That's different than what I thought but it makes a ton of sense.

I may not have run them long enough for that to happen. Any suggestions on how long that should take?
Any advice on this piece?

Really appreciating your help thus far!
 
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Old 01-08-14, 08:19 PM
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Any advice on this piece?
Sorry, sidetracked...

Hard to say. Those bleeders are the little manual pissers? It could take a while... how many GPM coming out the little pisser vs. how much might be in the pipe between the pisser and the mainline.

I figure you might have to get maybe a gallon out? more or less?

You better start prayin' that the pipes haven't split open!
 
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Old 01-08-14, 08:54 PM
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Those bleeders are the little manual pissers?
Those are the ones. After my last response I went back and continued to bleed them. You are probably correct in your assumption... maybe a bit less than a gallon. But warm water started to flow out. I let it flow for a few... then tightened the valve back up. It doesn't seem to have continued flowing through that pipe though, so the frozen pipes seem likely. However, I heard some creaking under the floor that wasn't previously there, so maybe it's softening things up.

You better start prayin' that the pipes haven't split open!
I haven't stopped doing that since I realized they might be frozen! I would have to tear up the floor to replace them and that doesn't seem like fun...

A few things along with that... 1) If they are indeed frozen, how do I prevent them from freezing again in the future? I'm assuming I can't really put antifreeze in the boiler system...
2) Is it possible that the reason my system pressure was low is because they did burst? (please say no!) It was probably low long before I realized it too... I'm thinking there was some air in the system already that made it easier to freeze.
 
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Old 01-09-14, 05:44 AM
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1) If they are indeed frozen, how do I prevent them from freezing again in the future? I'm assuming I can't really put antifreeze in the boiler system...
Other than insulating the area that the pipes are in, anti-freeze is the only other solution. Boiler systems use SPECIAL anti-freeze... PROPYLENE GLYCOL ... "Cryo-Tek" is one brand, there are others.

2) Is it possible that the reason my system pressure was low is because they did burst? (please say no!)
I wish I _could_ say no with more certainty, but usually by the time a pipe bursts, it has frozen solid on both sides of the burst and won't leak (lose pressure) until it thaws.

It was probably low long before I realized it too... I'm thinking there was some air in the system already that made it easier to freeze.
I don't think you mentioned previously that the pressure was low... " How low was it? "

I've never considered whether air in the pipes would make a system more prone to freezing or not... but my gut tells me there wouldn't be much, if any, difference.
 
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Old 01-09-14, 06:20 AM
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Moved posts to own thread....
 
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Old 01-09-14, 01:48 PM
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"Cryo-Tek" is one brand, there are others
Thanks! I'll look into that.

I wish I _could_ say no with more certainty, but usually by the time a pipe bursts, it has frozen solid on both sides of the burst and won't leak (lose pressure) until it thaws.
Right. I guess we will see when they thaw. Cross your fingers for me!

I don't think you mentioned previously that the pressure was low... " How low was it? "
Sorry... it was very low. Like, in between 0 and 1. However, when I re-pressurized the system and bled the valves in the working zone, I quit having water hammer and clanging sounds in that area. Those sounds had been happening for about a month now (maybe just a bit longer) and I was intending to re-pressurize everything when it got warm enough I could turn the boiler off. However, I neglected to look at the pressure gauge during that time. I am aware that my system loses pressure over time usually though. Another problem I was going to address in the spring, but I didn't get to wait that long.

I've never considered whether air in the pipes would make a system more prone to freezing or not... but my gut tells me there wouldn't be much, if any, difference.
I found another forum and a webpage that said it can... but who knows if they are just guessing or actually know it to be true. For my sake, I'm hoping they are right. Trying to figure out how to prepare if they are not though so I don't have to pull up my floor.

Moved posts to own thread....
Thanks! I only tagged onto this one because my problem was low pressure and NJ Trooper had previously helped with that on that previous thread.
 
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Old 01-09-14, 02:25 PM
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Cross your fingers for me!
Fingers AND toes... and my eyes too, since the beginning!

I am aware that my system loses pressure over time usually though
By all rights, it shouldn't, being a 'closed' system. MOST systems I would venture to say have small leaks here and there that go unnoticed for LONG time... decades even... ( mine included, but I finally found it 20 some odd years after moving in, inside a wall that was demo'd for some other work.)

Thing with leaks in a heating system, since there isn't much pressure to start with, they are usually VERY slow leaks. Coupled with the fact that the pipes are hot, the seepage evaporates before it hits the floor, but leaves behind telltale mineral 'growths', usually greenish/whitish fluffy deposits at the leaking joints. That's what you want to be on the lookout for. Not to be confused with the greenish deposits left by the unwiped soldering flux which won't create the fluffy growths.

I found another forum and a webpage that said it can...
Could be... but I'm trying to justify the physics behind the possibility, and I can't really.

Not reading back I don't recall if I posted this or not, but some preventative maintenance should be done on your expansion tank, especially since you have a slow and steady pressure loss report.

http://www.doityourself.com/forum/bo...sion-tank.html
 
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