finding leak

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  #1  
Old 10-15-20, 12:34 PM
K
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finding leak

I shut all valves and then let it sit for several hours and found the pressure did not change (so no leak in boiler). Then I opened only one valve for each zone and two of the zones the pressure did not change. But the third zone (my 2nd floor zone) the pressure decreases. It decreases slowly so must be a very small leak.

Went to each of the radiators upstairs and looked/felt for any leaks but didn't find any. So, I'm thinking the leak is somewhere in the wall. Any tips on how to track that down or is the only way to start opening up the walls to find it?
 
  #2  
Old 10-16-20, 06:39 AM
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Each time new water is added (manually or automatically) to the furnace heating system, there is the possibility of air entering the furnace heating system. This air will work its way to the highest part of the heating system which I believe is your second floor. When the second floor loop is heating (circulating the water) the air can be vented if a air purge device is installed. This lowers pressure if the make-up water needs to be added manually. You need to purge the loop of air. If make-up water need is added automatically. then I agree there is a leak in the loop. Not a plumber so can't recommend much as how to isolate. My approach probably would be to install butterfly valves on the second floor where the vertical supply pipes from the basement connect to the first register and before the vertical return pipe after the last register. This allow you to isolate the leak to one of three areas.
 
  #3  
Old 10-17-20, 09:23 AM
K
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I don't have an air purge device on the 2nd floor. The only air purge device is the scoop and hy-vent near the boiler. Just never have been able to get air out of this system so adding a air purge on 2nd floor makes sense. Would make getting air out of this system much easier and tell me for certain whether there is a leak on that zone. Thanks beelzebob!
 
  #4  
Old 10-17-20, 12:55 PM
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K,
This is just a suggestion that may help. Since you know you may have a leak on the scond floor and it's not in the visable basebooard units it must be in either the pipe going up to the units or coming back to the boiler. If you close off the other 2 zones and pressurize just that zone to 25 psi and bleed the air out and then shut off the feed valve so no more fresh water can enter and just run that zone alone for heat for a time and see if it maintains the pressure. If in fact you do have a leak as the water leaks out and with no water to replace it because you have the feeder closed you will lose the heat on the second floor because the water will not have enough pressure to get there anymore

Unfortunately this will not tell you what wall it is in but it will verify your leak in that zone. With the pump running and the hot water leaking you should feel or see it in the wall where it goes up. The pump should increase the pressure of the leak and you may be able to locate in either with a wet wall or difference in temp in the wall.

I had a pipe let go in my house in a crawl space and it came down into the bathroom wall and the wall go so hot I thought at first it was an electrical fire since there were wires there also.

Installing a high vent on the second floor will not solve anything. If you bleed the system right you do not need any high vents on your high points with your loop system. Those vents are needed if you have monoflo systems which cannot be bled effectively like yours can.

This is just a thought.
 
  #5  
Old 10-26-20, 11:16 AM
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Rather than butterfly or ball valves, install auto-air-vents at high point of each zone. Allow a few hours to vent, shut off water feed and see if there is pressure drop. If no pressure drop then likely no leak.

If there is a leak then payback is a future with automatic venting rather than eternal manual venting.

https://www.supplyhouse.com/Watts-05...Vent-3679000-p

The simplest and easiest way to vent is at high points of zones. Install auto vents and forget about venting. Did that years back on system with 8 zones, 2 circulators, and stopped even thing about venting. If an element stops heating will replace vent with spare $8.28 one and go back to sleep.
 

Last edited by doughess; 10-26-20 at 12:19 PM.
  #6  
Old 11-25-20, 06:07 PM
K
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First off, just want to say this is the absolute best forum! I have used all your advice and my boiler is running so much better! Plus I added valves from your suggestion from other posts to isolate components so I can quickly change them out when they fail in the future. Just want you all to know how much I appreciate your help!

Now for my current situation...I did bleed my upstairs zone a couple more times and now I'm seeing that it is maintaining pressure so thinking there is not a leak. But, I'm still hearing banging noises only when the water requires to be brought up to temp (so when we have flame on the boiler tubes. not sure if I have terminology right).

So, if the system has been properly bled, and that is an if and there still is noise, would the noise be due to scale? Haven't completely ruled out air in system but just wondered if scale may be the reason.
 
  #7  
Old 11-26-20, 01:11 PM
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k,
What do you mean by banging. Is it in the boiler or noise in the baseboards on 2nd floor. Next, how did you bleed that zone. Did you bleed in the basement on that isolated zone or did you install hi-vents and just depend on them. If you have a loop system hi-vents can be useless and only work somewhat without the pump running. With the pump running the water goes by too fast to get out of vents and can be more trouble than their worth. They can also suck air in when the pump runs to add to your air situation.

Individual vents are used on monoflo systems because the system cannot be bled the conventional way through the return line because of the piping.
 
  #8  
Old 11-26-20, 01:31 PM
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Spott, yes - I have a large monoflo system with many cast-iron baseboard convectors. Each baseboard unit has its own manual bleeder. As you can imagine, purging air from the system takes some time. My system has a conventional compression tank without a bladder separating the air cushion from the water. It works fine - and with the B&G Airtrol system, it never becomes waterlogged. The system has no automatic air elimination devices - they would be counter-productive because they would deplete the air cushion in the expansion tank.
 
 

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