Leak in church hot water heating system with inaccessible piping.

SteamingatMohawk

Over the years I have read about methods to seal piping leaks from the inside. I have no information about sealing a leak in a hot water heating system. The church I attend has 4 pumped loops. A 1 gallon a minute leak has been apparently identified in one of the loops.

The loop services several rooms on the first and second floor and has underground and in wall/ceiling piping. The leak is known because when the makeup water supply is in service the flow of water can be heard.

Since a large portion of the piping is not visible, does anyone have any suggestions on two things:

1. How to find the exact location of the leak. There is no evidence of such a leak other than the sound of water flowing.
2. If there is a method to coat the inside of the pipe to stop the leak (and the estimated life of such a repair).

Mad Dog_2

Not really..You must isolate the loops with valves & tees and test by sections. There are some gimmick liquids boiler Solder..Mad Dog

Larry Weingarten

Hi @SteamingatMohawk, You already know that if it's leaking in one place, it's likely to leak elsewhere in time. Whatever you do now is a temporary patch to get you by until new piping can be run… seems to me. The trick is in figuring out the path and then getting the powers that be to agree on a long term solution. A leak detection company should be able to find the leak with sonic or other tools. Then maybe a patch can be put on from the outside?? Or you can try some stop leak, as long as there aren't small passageways elsewhere in the system that could get plugged up. 🤔

Yours, Larry

Jamie Hall

My first thought is that at leakage rate if the problem were to be in a wall or a ceiling, somebody would have noticed it and started making noises. The altar guild, if no one else…

Which pretty well means it's more likely to be in an underground (or crawl space?) section.

Which really doesn't help much. And I completely agree with @Larry Weingarten . If it's leaking somewhere, either something flat out broke or froze, or the rest of the piping is just an accident waiting to happen. You may be able to locate the leak by sectionalizing the piping, but then the question is, how do you get at it?

If this is some of your domestic water supply, it may be more difficult to manage — but if it's in the heating system, I'd shut loop off completely — before the water actually does show up somewhere dismaying — and plan on taking some time this summer to replace that piping.

leonz

The pipe relining industry has developed a hot water liner for pipe recently and it has been written about in Trenchless Magazine.

DCContrarian

How big is the pipe? (inches?) How big is the heating system? (BTU/hr?) One gallon per minute is a huge amount of water. That's 1500 gallons a day. Where's the water going?

Depending on the pipe size and length I'd be tempted to fish a replacement piece of PEX rather than find the leak.

Mad Dog_2

Good luck trying to work pex through a 90 Degree elbow...of any size. Mad Dog

jumper

Abandon pipes and figure out new way. Eventually that will be done.

Mad Dog_2

Bypass surgery. Mad Dog

DCContrarian

https://forum.heatinghelp.com/discussion/comment/1800996#Comment_1800996

Bypass surgery, like you said. Not trying to sleeve with Pex, that way is madness.

tim smith

I agree with Mad dog & Jamie, bypass surgery is probably in order this summer. Most the ones we run into are 50 to 90 yrs old and have given there all. Probably can find a route over head to replace the undergrounds.

Good Luck

Tim

ratio

I found a leaking underground condensate line with an IR thermometer, I just followed the warm lines on the floor until I found a warm circle. It took a floor cut & a Dresser coupling, but it was fixed.

DCContrarian

Sometimes compressed air makes it easier to find leaks as it makes more noise leaking out.

But I'm still stuck on one gallon a minute. It's not shooting out somewhere?

SteamingatMohawk

Here is a "rough" sketch of the piping showing the arrangement in the boiler room. Lots of question marks and no markings of which return is for which pump. I wasn't familiar with the method of maintaining the temperature in the system, but got some help understanding that the boiler pump recirculates the hot water and the individual loop pumps supply water to the registers. Only one of the circulating pumps has any key to what it serves (it's the one marked sanctuary). I'm not sure of the path of the hot water lines to the faucets in that part of the building.

Since I wrote the initial post, I was informed the trustees had a plumber come who was able to identify which loop is affected by tracing the sound. The "good" news is that the loop feeds some rooms not that far away and underground piping may not be all that extensive. But it does go up to second floor spaces.

I appreciate the comments and will look into the comment about the hot water liner.

In my conversations yesterday with a couple of the trustees, I did mention the possibility/probability of future leaks in the system. Abandoning the loop and installing replacement piping, etc. to provide all existing functions will be a challenge, both physically and financially. Since this is a church, I'm not sure if it is allowable by code to eliminate the hot water to the faucets served by this loop.

SteamingatMohawk

Oh, by the way, when the church was built some floors had radiant heat, which leaked after some number of years and was "retired in place".

Jamie Hall

You have some real sleuthing to do here. Might be kind of fun, really.

First question at least for this post — you mention maintaining hot water to faucets in parts of the building. Say what? Are some of the hot water faucets run off the heating loops? They shouldn't be. They are classed as domestic hot water — and should be fed from some other system of piping! And some form of hot water heater — or heaters. It's not impossible that some of them are fed locally, from a small local heater in a cabinet or something?

However. If there is a faucet somewhere (look everywhere!) and it is fed off the offending heating loop, is the faucet leaking? I know it sounds obvious, but… otherwise a 1 gpm leak is a big ask.

Because… that amount of water has to be going somewhere. A gallon a day you can hide. Even a few gallons a day you can hide, at least for a while. But a gallon a minute? No. It's not in a wall or a ceiling — you'd know by now. So it has to be going into a drain somewhere, or into the ground.

As the saying goes, you hear hoofbeats — think horses, not zebras.

Larry Weingarten

Hi, One thing I like to do when looking for water leaks, is to have a look into the main building drain when no water is being used or has been used recently. If there is a trickle, it's a useful clue. Usually, it's a leaky toilet, but is a pretty simple check to make. 😎

Yours, Larry

SteamingatMohawk

You caught me with my foot in my mouth…not the first time on HH. I know better, the truth was hidden among all the other truths hiding deep in my mind, waiting for a time to be exposed.

I think I had messed up thinking the two tapoffs just before the left red and sanctuary pump loops are hot water. But like @Jamie Hall said that's not likely. I have no idea what they could serve.

Also a hot water heater is in the same room, so I can prove myself wrong by tracing its hot water line out of the room.

None of the boiler room floor openings have any water in them. I will check into that.

SteamingatMohawk

Thanks @Larry Weingarten for the suggestion.

DCContrarian

https://forum.heatinghelp.com/discussion/comment/1801098#Comment_1801098

You had mentioned that at one time there were heated floors that have been taken out of service. Could those be left over from that?

Mad Dog_2

My HS Football Co-Captain is an architect. When he built his house 30 yrs ago I insisted on Radiant & NOT running the domestic water under the slab...solder joints no less. 4 yrs later, we were chopping up his luxury bathroom floor with a demo hammer to fix leaks. After another slab leak popped up, I rerouted everything above grade. Then we added Radint fo a 20 x 20 den...

You MAY be the the smartest man in the room, but you're not always the most knowledgeable & experienced. Listen to someone who does it for a living. Mad Dog

SteamingatMohawk

@Mad Dog_2 The trustees did just what you said. When the trustees couldn't positively identify which loop is leaking, they got an experienced plumber to troubleshoot. He was able to determine the leaking loop and fortunately the valves in the loop don't leak. That loop is now isolated, and the rest of the system is fine (who knows for how long as mentioned earlier in this discussion by many of us).

Their plan is to eliminate use of that loop and establish a different heating system for that section of the building. Hopefully it won't be too horribly expensive.

Thanks to all for their comments.

SteamingatMohawk

So, here's the next question. Given that one leak has been identified, does it make sense to install a water meter in the makeup line so heating system consumption can be measured. The building has a water meter for all services. It seems to me for a small investment knowing how much, if any, water is being added is worth the cost. There is a second boiler for another part of the building that may benefit from a water meter as well.

The trustees were able to get a chart of total consumption ( maybe daily) and it was very clear when the consumption first increased, then when it got worse.

Does anyone have a specific meter recommendation?

DCContrarian

Makeup water is really bad for boilers. It brings in oxygen and corrosives that attack steel pieces and cause them to rust. Any level of makeup water other than zero is a problem that needs to be fixed. Putting a meter on the makeup water line seems to me to be acknowledging and accepting problems.

My recommendation is to turn the valve on the makeup water off, if your system can't maintain pressure then find and fix the leaks. It's always cheaper to fix the leaks than to replace the boiler.

leonz

Fix the leak and do not bother with a water meter as it is a waste of money. You need 2 or 3 cans+ of Fernox to counteract all the fresh water that has entered the boiler due to the leak.

SteamingatMohawk

I agree a large amount of makeup isn't the greatest thing, especially at 1 gallon a minute (1440 gallons per day). At the same rate as I pay for my house ($45.02 for 8186 gallons = $0.0055) which is walking distance from the church, that amount of leakage would cost $8 per day ($0.0055*1440 = $7.92).

Since the church is not occupied 24/7, the intent of the water meter is to be an easily monitored indicator of a leak. Unlike steam systems, hot water systems shouldn't consume water. Depending on the nature of any inevitable leak, the scenario that happened can be repeated. No one knows when or where the next will occur. The way the trustees found out about the leak is from the quarterly water bill from the town. The leak started in January, increased substantially in early March and was not found out until they got the water bill in April.

I agree installing a water meter is questionable, but given the history of the system (radiant heat failures years ago, current failure), the cost for a meter is inconsequential compared to the cost of leaked water even at much lower leakage rates. Installation cost is minimal. Additionally, no one knows what the effect of the current leak has on the ground below the building.

Installing it acknowledges the reality of a future possibility and accepts that another can/will eventually occur. I look at it as a preventive measure to ensure what just occurred won't be as extensive in the future. Abandoning and substituting something different for all of the current system is cost prohibitive.

I don't know if the other system has ever had a leak. I will look into it.

Once the current leak is removed from the system, it is a good idea to do a followup leak check to see if pressure is maintained in the system. There is an expansion tank in the system and temperature change in the system can mask a leak. These will have to be taken into consideration to get the truth. It's somewhat like leak testing an underground fuel tank.

Tell me more about Fernox. Treating the water seems worthwhile.

leonz

Fernox is a boiler treatment in an aerosol can that has a female hose coupler on the delivery connection and you simply attach it to a boiler drain in the system and open the boiler drain and then open the valve on the Fernox can and let the aerosol pump the boiler treatment into the system.

I don't remember the instructions exactly but I think treated my coal stoker boiler water when it was cold and off.

The Fernox can I used was blue in color, the current cans are white and come with pipe adapters for various connections to allow the aerosol to be pumped into your heating system.

They have videos and more information on thier home page.

www.fernox.us

SteamingatMohawk

So, here's the next question, even though some believe the idea is a waste of money.

Instead of a totalizing water meter, is there a device that can send a signal to the internet when an add of water to the system occurs?

A couple of decades ago, when I was on the board of directors of a senior citizen complex that had auctioneered pumps for the septic system, the only way to tell if an alarm occurred was if the folks living nearest the system could hear the alarm. When we did an upgrade of the system, we had an alarm added that fed the fire alarm system notification setup. That way there was notice 24/7 of the occurrence.

I wonder what might be available to monitor makeup water in the system that has underground piping and some history of leaks.

Jamie Hall

Do you have a burglar or fire alarm in there which sends notifications? If so, most of them have some way to hook in pretty much any dry contact switch to send an alarm — and I'm sure there are dry contact switches out there for flow sensing. Check with your alarm company?

DCContrarian

Is this system zoned? Do the zones have isolation valves? I'd be closing isolation valves to see which zone is leaking. At one GPM you should be able to hear the water running. Once the zone was located, I'd find every tee in that zone that was accessible and put isolation valves on it, see which side of the tee was leaking. Then I'd shut off the leaking section and wait for winter and see who complains.

AdmiralYoda

Wait. 1gpm? That is like my kitchen faucet running all the time?!?!? Every hour a 60 gallon puddle should be somewhere, and like you said in a single day that is 1,440 gallons. In a week that is over 10,000 gallons of hot water! That is enough to fill up an in-ground swimming pool!

That amount of water can't just disappear. There has to be evidence. Not to mention the humidity would probably be sky-high near the leak.

In this case a leak detection company would be money well spent. There is either a massive leak or someone got really creative with the condensate and connected it to the domestic hot water. Something smells fishy.

Mad Dog_2

BYPASS IT....Mad Dog

Sylvain

heavy water leak consequences ?

SteamingatMohawk

Here's the update. Yes, the leaking loop has been identified and isolated. Plans are being developed to provide a different source of heating to the affected area. With the warm weather, heating will not be an issue and hopefully the plan can be formulated and executed before the next heating season.

The subject of monitoring makeup water is to acknowledge the history and future possibility of another leak and to be able to "find" it by some means other than a quarterly water bill. The building already has some leak detectors in several rooms, but I don't know if they are just local or connected to the monitoring system.

Here's a small world side story. Yesterday, I went to the church to look for whatever may exist for a monitoring system. There is one and I found the name of the company that does any service. A few hours later, I was blowing the grass clippings off the sidewalk in front of my rental and one of the company's service trucks came down a side street across from the house. I waved the guy down and had a good discussion with him and he said he is pretty sure they can handle the situation. What a coincidence!!!!

If the trustees decide to do something, there are at least these choices:

Install a local reading water meter and take periodic readings. Someone would have to be appointed to take the readings. This is probably the least expensive option.

Install a locally "alarming" device.

Install a device that can connect to the existing monitoring system. This is probably the most expensive option, but gives 24/7 surveillance of the condition of the system and does not require any direct action on a routine basis.

One technical consideration is to identify equipment that will be able to identify the leak at a reasonably low level of leakage.

Obviously this concept is primarily for undetectable leaks in the system and can be a warning for small ones that become visible.

DCContrarian

Here's an alternative: shut off the makeup water valve and make sure your low-water cutoff works. If there is a leak, the boiler will shut off. Put a note next to the boiler saying if the boiler shuts off, check the low water cutoff and open the makeup water valve. If you're worried about pipes freezing or the building getting too cold, install a low-temperature alarm.

SteamingatMohawk

Obvious idea. One of my considerations in setting up a logging system is how long before it tells us something is going on. If nothing happens for "years" it might fall into disuse.

I was informed yesterday there are temperature sensors attached to the monitoring system, but do not know where they are located. I'll look into that. Assuming it already would provide enough warning it's easier than the wacky scheme I have been dreaming up.

More to follow.

PRR

does it make sense to install a water meter

No clue here. But a basic meter is 33 bucks plus wrenching. As you say, someone has to check it often.

(sorry for the size of image- what I pasted is much smaller)

https://www.amazon.com/DAE-AS200U-75-Couplings-Measuring-Gallons/dp/B06WLPZ92N

$52 buys a remote-read "Pulse output" meter which might get checked more often.

Stet

We found a leak under a slab by just using an infrared imager. The warmer area popped right up. And if there are more they should show up too. As most everyone said. You have one, probably more to follow. So if only one shows, I suppose you could go after it.

propmanage

I would first confirm what loop/zone the leak is on, check the pipe sizes coming and going and forget about any instant stop leak ideas. I would isolate it into zones and test the underground loop first, If it was in a wall or ceiling, you would already see the flooding. Once you know if it’s a supply or return underground just bypass and do away with that loop underground. One leak does not necessarily mean you will have lots more but if you want to be safe bypass everything underground if that the spot you find is leaking. Good luck.

FLYFISHER

If it is under the slab I would run the system up to temp overnight and use a heat detection gun to look for a hot spot in the floor. You may be able to follow the pipe and find a larger hot spot where the leak is.

Zman

IR is the first and easiest option for finding the leak. I would start by looking for a big plume when the system has been running for a while. If you need to pinpoint it further, start with a cold slab and then turn the system on.

The easiest leaks to hear have both pressurized air and water escaping. Put the system at pressure and use the screwdriver on the earbone, stethoscope, or electronic ground mic and listen for the sound.

Leak detection companies often use helium gas in the pipe and then look for the leak with helium detectors. This works well.

Trying to repair the pipe from the inside is difficult and super expensive. It is pretty unusual for it to make economic sense for water pipes. Sewer pipes with their long sweeps are a different story.