Hole in Steam Boiler

Jeremy_16

Hi Everyone,

After taking diligent water meter readings about every week or so, I started to notice the we were using a TON more water than usual on a weekly basis (we have an automatic water feeder hooked up to our boiler). I had a contractor come out and check for problems. They filled the boiler up and all of a sudden, water started pouring out of the boiler jacket. (FYI: We also tested the returns and found no leaks)

We have a Weil-Mclain 680 at our 16 unit residential building. My contractor took a picture of the hole in the boiler (see attached)

They filled the hole with some type of epoxy that they said would not be a permanent solution. They said they've seen it last a few years in some cases, but they recommended we take action at the end of the winter to replace the section or replace the boiler.

It's been over a week since the repair and our water usage has returned to it's normal amount. The patch seems to be holding for now. My contractor tells me the hole is located in the crown of the boiler in the last rear section of the boiler, so we have the option to replace just that section or replace the entire boiler. The cost for replacing the section is about 25% of the cost of total replacement (based on a ballpark estimate I got so far). The contractor said that there could have been one spot on the crown that rotted and got worse over time. I'm worried that if one section of the boiler rotted, that there could be other issues in other sections. I don't want to waste money replacing one section if other sections of the boiler could go as well, but the boiler is only 9 years old.

I guess there is really no way to know what will happen, but what would you all recommend as a course of action?

1. Replace 1 section or Replace the entire boiler?
2. How long should a typical weil mclain 680 boiler last before failing?

Any advice is appreciated. Thank you.

KC_Jones

What is the typical water usage of this boiler? 9 years is really short, 30+ years is not uncommon. If it was me I would replace the whole boiler. If another section or 2 fails you will be at or close to a new one and in the end you will replace the whole thing anyway. Before you replace you should figure out what caused the issue with your current boiler otherwise it will happen again.

Fred

If it were me, I'd probably put that money into a new boiler. So many things affect the life of a boiler that it is very difficult to say what the life expectancy might be, like how the boiler has been maintained, over its life, water quality, amount of water added to the boiler, over its life and if that water was immediately boiled to remove excess oxygen, how the boiler wad plumbed/installed, etc. Nine years is a fairly short life but when one section goes, the odds favor other sections being in nearly the same condition.

New England SteamWorks

I agree with the above.

Let's see some pictures of the near-boiler piping so we can rule that out or in as a potential cause.

Given that you have a 16 unit building, it's December, and you have an epoxy patch, I would also select your contractor and replacement boiler and have everything lined up and ready for launch in case the worst happens over the winter.

Use the find a contractor page on the main site. You will want a good steam man, not just to get you a good install, but also to determine the cause(s) of the failure.

Jeremy_16

In the last few years the boiler has used about 2 cubic feet (15 gallons) of water each week during the coldest winter months (sometimes a little more and sometimes a little less depending on how much the boiler runs). Does that amount of weekly water usage sound reasonable for a 4 story building with 16 apartments with about 50 radiators on a one pipe steam system?

The number always seemed a little high to me, but there are no leaks in the return that we can detect. We have a boiler feed tank and all return lines connect to one pipe that then connects to the boiler feed tank. We have disconnected that return pipe and connected a 50 gallon barrel of water to it as shown in pictures attached. The line water line on the barrel never moved.





The steam vents in the building are various ages, but none are leaking that we can readily see. The apartments are all occupied by tenants so we're not in them everyday to monitor things, but no one has ever reported leaks or water on the floor. We go through the apartments from time to time and never see any obvious water damage from leaks.

I'm wondering if a little bit of steam could be escaping from various vents. We have about 50 radiators in the building so it would be a big undertaking to replace all of the vents (and a big expense - especially if many of them are working fine). We have TRV vents in a few apartments (some are definitely over 10-15 years old). If we replaced those could we change just the vent or would the body need to be changed too?

What's the best way to know if an air vent is leaking? The only way I know is to take them off and blow through them (air should go through) and then turn them upside down and blow through them (no air should go through). Anything else to do? Any other way to check? Could air vents be the cause of excess water usage?

Fred

15 gallons of water a week is an outrageous amount of water to use. Either that boiler has had a leak in it for years and steam has been going up the chimney or there is a significant leak elsewhere in the system. Clearly adding that much fresh water every week for the last few years has contributed to the boiler rusting through. Wherever the leak(s) are, they need to be fixed when the new boiler is installed.

Jeremy_16

Hey RI_Steamworks and Fred,

Ri_Steamworks:

I have some basic knowledge of steam systems from reading lost art of steam heating and some of Dan's other books. As far as I can tell the near boiler piping is correct. I can upload some pictures of the boiler room later from another computer where I have the files.

We have a contractor that can do the boiler installation. I've calculated the EDR of the radiators and found that our current boiler is correctly sized. The simplest thing would be to re-install the same boiler if we choose total replacement. Does anyone have any suggestions other than Weil-Mclain?

Fred:

At 2 other similarly sized buildings we manage the water usage is about 7-10 gallons a week. Could it be that these large systems with 50-60 radiators just lose more water? I know that ideally we should lose almost no water but somehow the water is getting out.

I don't think leaking returns are the culprit because I think we would be losing way more water than just 10-15 gallons per week and at some point the leaks would get so bad we would have steam coming up through the floors- which we don't. We've even replaced returns in the past in some of these buildings where they were badly leaking and obviously needed replacement.

Could we have several radiator vents all contributing to this water loss? If we remove all of them and blow through them will this give us definitive results to see if they are good or bad? I'd like to know before spending money on all new vents or many new vents.

KC_Jones

Massive excess water use. If I was to guess I would say your weekly usage should be your yearly usage.

Also your comment about expense...compare the cost of replacing vents and doing a complete system evaluation to the cost of a boiler replacement every 9 years....or less.

Fred

@Jeremy , I have a radiator count of 15 and an over-sized boiler that could handle about 5 more similar sized radiators. Boiler size is 866 Sq. Ft. of steam. The only (and I mean Only) water I use is once a week I blow down about 1 to 2 quarts of water from the float type LWCO weekly and replace that 1 to 2 quarts. Yes, the larger the boiler, the more water that will be lost to some vents that may not seal completely/consistently or some level of evaporation when those vents open but it should be minimal, like maybe a couple quarts or so a week. Something is going on with each of those boilers if you are using 7 to 15 gallons of water per week. No to your comment that you should see steam coming through the floor. By the time water gets into the returns, it's water, not steam. There has to be leaks, either in a main, a riser, maybe hidden in a wall, in the buried wet returns or in multiple main vents or radiator vents/valves/radiator run-outs. or it is going up the chimney, in the form of steam and condensing on its way out. To your point that leaks only get worse, that is true and I would suggest that 15 gallons a week is an indication it has gotten worse. It did not start out losing 15 gallons a week. How rapidly those leaks get worse is anyone's guess but something is seriously wrong. I would suggest you look at what is coming out of the chimney during a heating cycle, then you have to look at those buried returns. Maybe you can do some kind of pressure test, if you can isolate both ends of the wet return? then ask all the tenants if they have leaking vents and/or excessive moisture in their apartments. It would take a good many bad radiator vents to lose that much water. I would think someone would be complaining. Blowing through a vent will tell you if it is open. Turning it upside down and blowing into it will tell you if it closes in an upside down posion but you need to test then in an upright position and they need to seal , ideally completely.

Jeremy_16

KC_Jones and Fred,

KC_Jones:
Just to give some perspective on the water loss. We went from losing about 15 gallons a week to about 125 gallons a week when the hole in the boiler developed. With the epoxy patch it's again losing about 15 gallons a week. It has been losing about this amount for at least 5 years and hasn't gotten better or worse (that's about when I started keeping track).

I'm all on board with replacing vents if we can determine that that's that cause, but what's the best way to do that? We have TRVs, vent-rite adjustable vents, and Gorton D vents. If I remove the vents and blow through them right side up and upside down will this tell me if they are working properly? Is there anything else I can do to check?

Fred:

Thanks for the perspective by comparing your system. I have about 1650 square feet of EDR in the radiators in this building. The reason why I said I would see steam coming from the floor is because we've had leaks in 2 of the buildings we manage and there was steam coming up from the floors both of the times (not a ton, but it was obvious there was a problem with the return -although it's not steam in the returns, it still is very hot right after the system has run and it's returning to the boiler).

We can see most of the steam mains in the building and haven't noticed any leaks in any of them. We did the 50 gallon barrel test on the returns and the water line in the barrel didn't move. I'm leaning towards radiators and radiator valves because I don't think it's anything else, but that's seems like a surprising amount of water that could lost in that manner (especially because nothing is readily apparently leaking when we've gone in to these apartments).

New England SteamWorks

Leaking steam = leaking water

Fred

I'm not sure what that barrel test is suppose to do? Depending on the water line in the boiler, return water could be stacked two feet or more into any and all returns that drop down into that buried wet return and those returns would refill with each heating cycle. How is that 15 gallons of water being replenished to the boiler? I don't know how long that barrel has been there but if the boiler is using 15 gallon a week, it has to be getting additional water from somewhere and if not from that barrel, from where? The barrel test may be flawed if the water in it didn't drop, and the feed tank was truly disconnected then the boiler water had to drop. 15 gallons a week is a little better than 2 gallons a day or about 5 or 6 ounces an hour. If the leak is somewhere where it only leaks during a heating cycle and we assume that the boiler runs maybe 50% of the time, then that's 10 to 12 ounces an operating hour.

Jeremy_16

RI_SteamWorks,

You're right, but that many gallons from leaking steam that no one is reporting? Could that be? Is there an easy way to test these vents to see if they are leaking a little bit of steam? I don't think any are stuck open the entire time the heat is running.

Fred

Are there any hot water loops running off of that boiler?

Jeremy_16

Fred:

The barrel was supposed to add some weight to the water already in return lines. If there was a leak the return lines the water line in the barrel would have dropped. The barrel was hooked up to test for leaks. It's not there during normal operation. The 15 gallons are being added by the automatic water feeder, which is connected to the boiler feed tank. The boiler feed tank is connected to the boiler. When the pump control on the boiler senses low water, it calls for water from the boiler feed tank. If there are no leaks in the system at all, then the water in the boiler feed tank is just recycled water from the returns coming back from the radiators. If there are leaks, which there are, then occasionally the automatic water feeder will add water to the boiler feed tank to replenish the supply.

Yes, there is one hot water loop. That was pressure tested with air to check for leaks and none were found.

New England SteamWorks

Jeremy said:

RI_SteamWorks,

You're right, but that many gallons from leaking steam that no one is reporting? Could that be? Is there an easy way to test these vents to see if they are leaking a little bit of steam? I don't think any are stuck open the entire time the heat is running.

I guess you don't know tenants very well. If you were a tenant in an apartment that had steam heat, would you be surprised to see steam? Have you done any education or outreach? Have any of the vents been replaced in living memory?

Good dry steam is also invisible, btw.

Fred

Jeremy said:

Fred:

The barrel was supposed to add some weight to the water already in return lines. If there was a leak the return lines the water line in the barrel would have dropped. The barrel was hooked up to test for leaks. It's not there during normal operation. The 15 gallons are being added by the automatic water feeder, which is connected to the boiler feed tank. The boiler feed tank is connected to the boiler. When the pump control on the boiler senses low water, it calls for water from the boiler feed tank. If there are no leaks in the system at all, then the water in the boiler feed tank is just recycled water from the returns coming back from the radiators. If there are leaks, which there are, then occasionally the automatic water feeder will add water to the boiler feed tank to replenish the supply.

Yes, there is one hot water loop. That was pressure tested with air to check for leaks and none were found.

I understand all of that BUT, if there is a leak elsewhere in the system, other than the return, that barrel test means nothing. Let's be clear about the fact you are losing water from somewhere. You just have to figure out where. All of that added fresh water is clearly a huge contributor to this boiler's demise and it will be the same story for the next boiler unless it's found and fixed.

Fred

Does that feed tank have an overflow to a floor drain? Is it possible you are losing water out of it into the floor drain?

Fred

A couple more thoughts: What pressure is the boiler running at?
Second thought: Does the water in the sight glass bounce a lot? Does that boiler need a good cleaning and several long slow skims? If it has oils on the surface of the water, it could be pushing some of the boiler water back out into the return/feed tank and if there is an overflow on the feed tank, out to a drain.

KC_Jones

To the OP remember steam is invisible. I have seen a leaking vent and knew it was leaking and never saw anything. Put a cold piece of metal next tot it and bam it gets wet quickly. Mirrors work to, I use a chrome plated wrench.

Jeremy_16

RI_SteamWorks said:

Jeremy said:

RI_SteamWorks,

You're right, but that many gallons from leaking steam that no one is reporting? Could that be? Is there an easy way to test these vents to see if they are leaking a little bit of steam? I don't think any are stuck open the entire time the heat is running.

I guess you don't know tenants very well. If you were a tenant in an apartment that had steam heat, would you be surprised to see steam? Have you done any education or outreach? Have any of the vents been replaced in living memory?

Good dry steam is also invisible, btw.

I know what you're saying about tenants not knowing to report things or even being too lazy to report things sometimes, but I and the property manager are also in and out of those units many times over the years in the winter and we haven't noticed any vents obviously leaking steam. We have replaced some vents over the years, but definitely not all of them. I don't have a list of when we replaced one or another so it's possible some have been there a long time. I wonder if some are losing just a little bit of steam and we didn't notice because we aren't there everyday.

Should I remove all of them and blow through them? Or just do the mirror test as KC_Jones described?

Jeremy_16

Fred said:

Jeremy said:

Fred:

The barrel was supposed to add some weight to the water already in return lines. If there was a leak the return lines the water line in the barrel would have dropped. The barrel was hooked up to test for leaks. It's not there during normal operation. The 15 gallons are being added by the automatic water feeder, which is connected to the boiler feed tank. The boiler feed tank is connected to the boiler. When the pump control on the boiler senses low water, it calls for water from the boiler feed tank. If there are no leaks in the system at all, then the water in the boiler feed tank is just recycled water from the returns coming back from the radiators. If there are leaks, which there are, then occasionally the automatic water feeder will add water to the boiler feed tank to replenish the supply.

Yes, there is one hot water loop. That was pressure tested with air to check for leaks and none were found.

I understand all of that BUT, if there is a leak elsewhere in the system, other than the return, that barrel test means nothing. Let's be clear about the fact you are losing water from somewhere. You just have to figure out where. All of that added fresh water is clearly a huge contributor to this boiler's demise and it will be the same story for the next boiler unless it's found and fixed.

Fred, you're right about that. We were just testing the returns with the barrel test. We definitely have water/steam escaping somewhere else.

Jeremy_16

Fred said:

Does that feed tank have an overflow to a floor drain? Is it possible you are losing water out of it into the floor drain?

It does have an overflow, but I'm confident it's not overflowing (I'm in the boiler room all the time especially in the last few weeks given the issues and the water line in the site glass of the boiler feed tank is always about 1/4 to 1/3 high). The overflow is not directly connected to the drain, so I would be able to see water on the floor.

Jeremy_16

Fred said:

A couple more thoughts: What pressure is the boiler running at?
Second thought: Does the water in the sight glass bounce a lot? Does that boiler need a good cleaning and several long slow skims? If it has oils on the surface of the water, it could be pushing some of the boiler water back out into the return/feed tank and if there is an overflow on the feed tank, out to a drain.

Fred:

Pressure is set at around 1 pound or so; don't worry, it's not cranked up. There is no surging in the site tube. The boiler was just cleaned this fall and the LWCO is working properly and pigtails are all clear. Nothing is backing up into the boiler feed tank.

Fred

It's always possible there are other, smaller leaks in that boiler that the service guy just missed because he was focused on repairing that large hole.
Also, when you check the radiator vent's, take a look at the supply valve. They can leak steam around the valve stem too.

Jeremy_16

KC_Jones said:

To the OP remember steam is invisible. I have seen a leaking vent and knew it was leaking and never saw anything. Put a cold piece of metal next tot it and bam it gets wet quickly. Mirrors work to, I use a chrome plated wrench.

KC_Jones:

Thanks for the advice. You said you knew the vent was leaking but couldn't see it. How did you know it was leaking? Were you going around testing the vents with the chrome plated wrench?

KC_Jones

Yes I have done that, but I can hear it. If the rad is hot and something is coming out (audible), it's usually leaking. It should be closed tight when it's hot.

RomanGK_26986764589

@KC_Jones I have a Gorton vent on the rad which is silent when the rad is full of steam but it still fogs up the mirror quite a lot.

KC_Jones

Could have dirt on the sealing surface or it's going bad?

RomanGK_26986764589

No, I think I had a bad batch because I bought a few of them last year but had to change them out a month later since all of them were letting steam out and being noisy. The pressure rarely exceeds 0.5 psi. The quiet and steaming one is the left over from that batch. Just need to bring myself to change it. I have MOM vents on other rads and they are much better.

NYCDave

@Jeremy, would you care to post any follow up to how/if this was resolved? I am dealing with a (residential) boiler with a similar issue (using huge amounts of water, found a hole in the boiler, but still wondering what lead to it and if the hole explains where all the water is going). Also could you tell me more about the epoxy patch they used on the hole? Would like to nurse our boiler through until spring/summer when we can replace it without a rush... Thanks!

Jeremy_16

@NYCDave The epoxy patch that was done has held up so far. The water usage has returned to "normal". I say "normal" in quotes because it's still using 7-15 gallons a week but it has always used that amount since we began tracking the usage. It's definitely not losing 120 gallons a week from the hole anymore. I don't know what the exact epoxy was, but I left a message for my contractor to ask him to let me know.

I still am trying to figure out how we are losing the other 7-15 gallons of water per week. I went through the apartments and figured out how many radiators we have and what kind of steam vents we have and am considering replacing them all. When I went through the units I didn't see or hear any vents noticeably leaking steam, but sometimes it's tough to tell. Replacing all vents may be the easiest solution, even if it's expensive.

I also found one drip pipe off of the steam main that may not be connected to newer return pipes we replaced a few years ago. The drip may be connected to the old return pipes which are no longer connected to the boiler. So we could be losing some water that way too. I need to open walls inside an occupied unit to test that theory out and haven't had time yet.

I'll update once I figure everything out.

Jeremy_16

@NYCDave My contractor texted me that what he used was two part export that comes in a stick.

Hopefully whoever you are working with will understand what that is. Good luck with your boiler.

NYCDave

Thanks @Jeremy, look forward to hearing how things turn out... Posted my musings on the volume of water one can lose from a boiler hole recently... seems consistent with the water loss we are seeing, and yours as well, and I guess in your case, plugging the whole eliminated the increase in water loss, so this confirms the theory!

MilanD

@NYCDave @Jeremy

We had a pin hole leak in the steam chest on a 40 gal capacity boiler 780mbtu input. It was making up 11 gals every 10 days or so. Hole was smaller than pencil eraser.

For anyone with a suspicion, if you can hear hissing that sounds like a water running through a faucet. If your regular op pressure is low, and you suspect a hole in the boiler, raise the trol pressure up for a cycle and see if you can hear anything standing by the flue box.

Larger holes won't hiss, but you also may not get much of thw pressure on the gauge either. I believe water loss is commensurate with the hole size.

MilanD

And, btw, check your water for chlorides. I am now working on figuring that one out and how to reduce it. I'll post about it when I find out more.