Leaking Elbow in Cramped Quarters

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Old 08-19-14, 07:38 PM
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Leaking Elbow in Cramped Quarters

Many months ago I noticed a stain on a first floor ceiling that is below a bathroom on the floor above it and attributed it to dripping condensation on a cold water pipe. I ignored it for some time since it was a small stain and when I noticed it, the ceiling was dry. Recently I cleaned out the bedroom closet next to the bathroom and while it was empty I decided to remove a small access panel in the closet and put some insulation around that pipe to prevent a further problem if we had a real humid day.

Unfortunately I couldn’t be that lucky. What I found was a small leak on a copper elbow joint that faces down. It is not currently wet but there is a lot of corrosion and residue where that water has leaked and evaporated in the past. To make matters worse, this particular elbow is less than 2 inches from wood below it and to one side and it is beneath a one piece tub and shower with another copper pipe less than an inch above it. There is no way you can move either the horizontal or vertical pipe enough to get the old elbow out or a new elbow in even if you could apply heat without burning the house down in such cramped quarters.

The only thing I can think of is to cut the elbow out with a hack saw (no room to swing a pipe cutter) and then use a Shark Bite hot water hose to join the two ends. Even then, I am not sure if I can get enough space between the pipe ends to make the connections. In addition this pipe is part of the baseboard heating system and the temperature of the water out of the boiler is over 200 F and the limit for Shark Bite is 180F. The specification however also says that temperature limit is for pressures up to 200 PSI so I am going to contact them to see if a higher temperature is possible at a lower boiler pressure of 20 PSI, but I am not hopeful.

Short of tearing out the one piece tub and shower to make getting at the pipes easier and reworking a few of the good pipes as well, I am at a loss for a possible solution other than reducing the boiler temperature which I would rather not do. Any other thoughts on how to fix high temperature baseboard heating copper pipes where using a torch is not possible.
 
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Old 08-19-14, 07:55 PM
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I guess the Shark Bite hose is out. On further investigation it looks like only one end will connect to a copper pipe. They do not appear to make one for a copper to copper connection. Now I really do need an alternative approach.
 
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Old 08-19-14, 08:18 PM
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the temperature of the water out of the boiler is over 200 F and the limit for Shark Bite is 180F.
di di dah dah di dit

First off, I'm sure that there is no reason the boiler needs to be at 200F. The de facto 'standard' is 180F, so start off by turning that down to at least 180 and save a few bucks on fuel.

Next, I'm not sure what you mean by the limit for Shark Bite being 180F ? Did you see that in a spec sheet?

I just pulled the spec sheet and the fittings are rated to 200F. Again, why are you running your heating system over 200F ?

use a Shark Bite hot water hose
Or, maybe you are looking at the flexible hose thingies that SharkBite has for connecting water heaters and such?

They do not appear to make one for a copper to copper connection
Maybe not the "hoses", but all the SharkBite fittings are designed to do copper to copper.

(no room to swing a pipe cutter)
There are special tubing cutters made for close quarters.

You don't want to use a hacksaw if you intend to use a SharkBite fitting.

To be successful with SharkBite, there must be absolutely NO BURRS on the pipe else you will nick the O-ring and it won't seal. If the quarters are that tight, you'll never be able to get the burrs off after hacksawing the pipe.

There are MANY different types of SharkBite fittings..

SharkBite Fittings , SharkBite PEX Fittings , SharkBite Fittings for PEX and Copper - SupplyHouse.com

and in fact there's a 5% off promotion going at SupplyHouse.com

Is it possible to get some photos of the area in question? If we can see it we may have more suggestions.

73!
 
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Old 08-20-14, 07:21 AM
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I could not find how to reply with quotes so I will just reply to your suggestions in the order you presented them.

The 200F boiler temperature was the default value for boiler. I didn’t change it because I thought to maintain a room temperature of X degrees required Y amount of BTUs and that was independent of the water temperature. If the boiler was at 200F I thought it would mean less wear and tear on the circulator pumps since the boiler would not have to run as long to produce the needed BTUs.

I am not sure where I saw the 180F limit but I did a search for those specs. using Google and came up with this link that I hadn’t seen before so there at least two places where 180F is shown as the upper limit.

Amazon.com - SharkBite 95012 Push-Fit Fitting - Coupling - Pipe Fittings

Based on your comment however, I located the Shark Bite web site and found that they do indeed say 200F. Since they are the final authority I would say that is very good news.

Even better I also found what you were suggesting is correct. I found that I was basing the no Cu to Cu connection for hoses on the description for “Flexible Water Heater Connectors” but they also make “Flexible Coupling Hoses” which apparently can be use for Cu to Cu connections.

I did know about the Shark Bite elbows, and they would have been my first choice, but it would be a real problem to move either of the pipes back. I would think that the method for installing an elbow would require that you push one pipe back, install it on the other pipe, and then bring the first pipe back into to the elbow. I don’t think there would be enough internal clearance to put the elbow on crooked on one pipe until the other end of the elbow is over the second pipe but I do not know that for a fact.

I do have small pipe cutter that might work. I will have to have the XYL move all her shoes out of the way and take another look at it with that in mind. Mine is a very short regular pipe cutter but I see now that there also some circular ones that you can purchase that require even less space.

Thanks for replying and 73.
 

Last edited by pk232; 08-20-14 at 09:35 AM.
  #5  
Old 08-20-14, 10:15 AM
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Hi pk –

I’m no plumber for sure so you have to take what I say with a grain of salt. And I certainly don’t want to try and talk you into something that would burn your house down presuming that you would pay any attention to what I have to say anyway, lol.

But I have soldered in some very tight quarters and it may not be as bad as you think. I guess it is all configuration-dependent. You can use cookie sheets or other metal barriers to protect the wood. You can also buy small heat cloth or flame protection blankets (HD used to sell them in my area).

I very securely prop up cookie sheets and/or pie tins, tack up heat cloths, etc – whatever is needed to protect wood, etc. If there is enough room I sometimes double up using 2 cookie sheets or cloths per area, etc.

I then do a dry run moving my hand with the torch the way it would be moved when doing the actual solder job, looking to make sure everything would be protected from the flame. I also keep a fire extinguisher around and a bucket of water (never had to use those yet, lol).

I use a MAPP torch (not expensive) and it doesn’t take very long at all to get ¾ copper or even once inch, hot enough for solder to flow.

As far as not being able to move the pipes to get a joint apart, I think you could cut out a section and then use a repair coupling. The repair coupling slips back over the old remaining pipe, then you insert your new section and slide the repair coupling forward partially over the new – thus bridging the old with the new (and you need to solder the repair coupling of course.)

In fact you could cut your pipe at any place it would be more convenient to solder and solder at those points. In other words, for example, if it would help, on a workbench you could solder the 90 elbow with pipe stubs of a carefully chosen length, then cut your old pipe and patch in the new elbow section you just made with repair couplings, having picked spots where it would be easier or more comfortable for you to solder.

Just a thought or two! Good luck!
 
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Old 08-20-14, 04:07 PM
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There's also an aerosol spray called " Cold Fire " that can be useful in cases such as this.

Scroll down this page:

FireFreeze Products - FireFreeze

Not sure where you can buy it in your area, but it's worth a look-see around.

As ZD has said, often you can cut out a bigger section than need be, make up a piece on the workbench and then safely solder in, or use the sharkbites on the made up piece.

The 200F boiler temperature was the default value for boiler. I didn’t change it because I thought to maintain a room temperature of X degrees required Y amount of BTUs and that was independent of the water temperature. If the boiler was at 200F I thought it would mean less wear and tear on the circulator pumps since the boiler would not have to run as long to produce the needed BTUs.
Let's talk about this a bit...

First off, there really is no 'default' value. True that the boiler may have shipped with this setting, but that's no reason to leave it there.

To maintain a building temperature, one must simply replace the heat that is lost. Let's say your home has 50K BTUH of heat loss at a given outdoor temperature and maintaining 70 indoors.

Let's further say that your home is heated with fin-tube baseboard rated at 550 BTUH output AT 180F WATER temp, and there is 90 feet total installed.

In order to replace the heat lost in the hypothetical case, your system would have to fire the boiler up to 180F. ( 90 feet X 550 BTUH/FT = 49500 BTUH - close enough )

If your home has MORE than 90 feet installed, the water won't need to be as hot to output the required BTU to replace the lost heat.

Of course, the reverse is true... if you have LESS than 90 feet installed, you would need hotter water.

Considering the longevity of a typical circ pump, and comparing the cost of replacing a pump every 15 years or so to the price of fuel, one can quickly come to the conclusion that it's a false economy to run the boiler hotter to 'get more life' out of a pump.

I'll give one example using my home... I've got quite a bit more baseboard than needed because of improvements in insulation, air sealing, windows, doors, etc, that have been made over the years. Perhaps before all this work was done, it was the correct amount of baseboard... but it's more than enough now. The net result is that I was able to install a smaller boiler by HALF than the old one that came out, AND the boiler almost never fires up past 150-160 or so.

So turn that high limit down to 180 for starters, and over the course of next winter, take some notes on the water temperature that you see on the boiler gauge when it's REALLY cold outside. That will tell you if you need to run hotter. (I almost would guarantee that you won't.)

And, if you DO have fin-tube baseboard, and it's been years since the covers have been off and the fins brushed and vacuumed, then do that too... You'll be surprised at how much more heat you can get out of them! It only takes a thin coating of dust/pet hair to reduce the heat output.
 
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Old 08-21-14, 05:23 AM
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But I have soldered in some very tight quarters and it may not be as bad as you think. I guess it is all configuration-dependent. You can use cookie sheets or other metal barriers to protect the wood. You can also buy small heat cloth or flame protection blankets (HD used to sell them in my area).
Thought I'd throw this in. When I find soldering or using a torch in tight quarters I use pieces of ceramic tiles as a fire barrier. In fact they have become standard fair in my tool box.
 
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Old 08-21-14, 07:44 AM
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Well I got something good out of this thread, FireFreeze and ceramic tiles. Good ideas IMHO.
 
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Old 08-22-14, 10:58 AM
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Using “default” instead of “as installed” or “as shipped” was a poor choice of words on my part. Too much time working with computers I guess.

Based on your comments however I did do some additional reading and found that boilers can be more efficient if you can increase the differential temperature between the water being heated and flame temperature to maximize heat transfer so that more heat ends up in the water and less in the exhaust gases. That means the water temperature of the return water should be as low as possible and the lower the temperature of the water leaving the boiler as well means the average differential will also be higher for the complete cycle. I will lower the temperature.

Thanks to everyone who had suggestions on how to protect the wood from overheating. I plan to pull the panel off again in the next few days and look everything over a second time and come up with a best course of action with your comments in mind. Luckily it is still summer so I was able to turn off the thermostat and close the shut off valves on the both the supply and return lines to that zone so I can take my time without worrying about the leak becoming worse. It may not have been necessary to do that since there has probably been a small leak there literally for years but why take a chance.

At the moment I am leaning toward using Shark Bite hoses. It is not only the wood in the wall but also the fact that the plywood sub floor is very close as is the bottom of the Fiberglas tub. As icing on the cake I would have to lie on my side and one connection would have to have to depend on capillary action to draw the solder up. Add in the fact that it will be difficult to apply heat and solder to the far side of the joint which is out of sight and you have a nightmare particularly if when all was said and done it still leaked and I was right back where I started from. You have to remember that although I have done my share of plumbing requiring soldering in the past, I do not do it for a living and there is a very good reason for that besides the fact that I hate plumbing.

Thanks again.
 
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Old 08-22-14, 12:09 PM
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That means the water temperature of the return water should be as low as possible
That's partially true, but if you lower the return temp too much, you run the risk of causing condensation and corrosion in the flue.
 
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Old 08-22-14, 01:04 PM
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I will keep that in mind. There always has to be a balance or as someone once said, "All things in moderation"
 
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Old 08-22-14, 01:58 PM
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Read an article by John Siegenthaler entitled DO NOT GO UNPROTECTED in the march 2014 issue of HPAC magazine .
 
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Old 08-22-14, 03:00 PM
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Right, all things in moderation... except beer.

There are boilers that are DESIGNED to squeeze that last few percent of latent heat energy from the hot flue gases by INTENTIONALLY 'condensing'. The latent heat that goes up the chimney in the form of water vapor is extracted when condensed.

In general, this type of boiler is also designed to MODULATE the burner heat also. It will automatically 'turn down' the heat when the controls tell it that it's not needed. This type of boiler is called a MOD/CON, short for MODulating/CONdensing.

The design aspect is the choice of materials that won't be damaged by the ACIDIC condensate, AND a method of collecting, neutralizing, and disposing of the condensate down a drain.

A CONVENTIONAL boiler (which is what I think you have, but I probably shouldn't ASSume, so please let us know what the make and model of your boiler is.) should NEVER condense. Ideally, the hot flue gases inside the boiler should never contact a surface that is less than 135F (for a GAS fired system). This can be assured by being certain that the RETURN water is never below that temperature, which would in turn cool the heat exchanger surfaces to below the 'dew point' of the flue gas.

In reality though, ALL boiler will condense at some point. The trick is to minimize the time that the boiler is cool enough to cause condensation. When a heat call begins, the system should heat up fast enough, and run long enough for the surfaces to come up to temperature so that any condensate that does form is dried out. For corrosion to occur, there has to be WATER. Dry the water and no corrosion.

Fin-tube baseboard systems generally meet the above goal. They heat up quickly and the return water is usually above the dew point in a few minutes.

Systems with large volumes of water, or with ANY cast iron heat emitters should ALWAYS have boiler protection built in to the piping design. This is because it takes a long time for those systems to heat up and there would be condensation occurring that entire time inside the boiler ( not to mention the flue pipe and chimney! )

I would not recommend lowering the High Limit below 160F for this reason. The boiler MUST be allowed to heat up enough that the return water is above the dew point for a long enough time in order that the boiler is not 'put up wet'.

Remember, the hot supply OUT of the boiler is generally 20-25 F hotter than the return back to the boiler. Do the math and you will understand why 160F is my recommendation.
 
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Old 08-22-14, 03:01 PM
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Saves, how would one go about reading that article?
 
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Old 08-22-14, 04:13 PM
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Google :archives hpac march 2014
 
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Old 08-22-14, 04:27 PM
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My gas-fired, hot-water boiler system has a relatively high water volume and has cast-iron heat emitters. It is a warm-start, non-condensing boiler, and I run it at 180 deg. That way, I don't have to worry about condensation. Would it more efficient to run it at, say, 160 deg, or even less? Sure, but that might only save $50, or so, per year in fuel. (My total fuel cost for space heating is about $1000 per year, or a little more.)

I spend more for snow removal and lawn care combined, by a factor of about two or more, than I spend on gas for space heating. I could save much bigger bucks by telling my snow-plow guy to come only when there is 4" of snow (instead of 2") and cutting back my lawn guy to come only when I call him, instead of when he thinks it needs mowing. But I'm not going to change my boiler operating temp, my snow plow guy, or my lawn man - I've got bigger fish to fry.
 
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Old 08-22-14, 04:30 PM
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Why not simply post the link to the article?

Must be another magazine with same sorta title...

Here's a link to allow reading that article:

http://www.hpacmag.com/news/siegenth...949230/?&er=NA

I'm not going to change my boiler operating temp, my snow plow guy, or my lawn man - I've got bigger fish to fry.
Did someone suggest that you do?

You gonna do them fish on the grill? I'll bring the beer.
 
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Old 08-24-14, 05:43 PM
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NJ in answer to your question it is a Weil-McLain GV-4 Series 3 boiler and there is a bypass circulator pump that runs to minimizes the amount of time that the water is below a 130F when the boiler first fires or even if a lot of zones should call for heat at the same time. I do however try to minimize the latter at least by staggering when the timer based thermostats go to their daytime settings early in the morning. It is fin style baseboard heat by the way.
 
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