Steam coming out from behind the boiler...

KconQueso · February 5

Hey all,

I have a bit of an issue with my boiler and have seen that the people here seem to know a lot, so I was hoping I can get some advice.

I have a Weil-McLain EGH-95 low pressure boiler in my building that was installed in 2011. About a month or two ago I noticed a bit of steam emanating from behind the boiler. Not a lot (think of a pot simmering), but enough that you can see it coming out when you enter the boiler room.

In early December, I had gone to the boiler to inspect it and added a little water to it as the gauge showed that it was low. I didn't fill it all the way obviously. I then noticed some water coming out of it and immediately turned it off to inspect it. The water flow stopped but it wouldn't turn back on so I called a plumber who got it working again and inspected for a water leak, which there was thankfully none. Using an endoscopic camera though we did look underneath and noticed the sections were a little wet. While there has been no water leak since then, later that evening I did notice the steam for the first time. I texted him and he said that it may self-seal (which it hasn't).

The amount of steam hasn't changed since I noticed it and it only seems to happen when the boiler is on for a long period of time or on very cold days. From the research I've done so far, my understanding is that there may be a small pinhole leak or crack on one of the sections above the water line or possibly one of the gaskets between the sections has wasted away.

I lowered the temperature by 2 degrees to 71F, the pressure in the boiler has remained low (>5psi), and there are no major signs of corrosion on the system. I think the problem is small enough that we can get through the winter, however, the gas bill has gone up by a lot in the last 2 months and I want to try to tackle this issue if possible.

If I'm not mistaken, there are boiler sealants (like Hercules) that can address water leak issues, but my understanding is that those probably won't work if it's steam and the leak is above the water line. I was thinking of taking off the boiler's top cover and insulation layer and seeing if I can visually see any cracks or pinholes. Maybe also turn off the boiler and fill it all the way to see if it leaks water from near the top? Are there any sprays, epoxys, or sealants you can recommend I can use for upper sections or gaskets?

Any and all advice is appreciated. Thank you in advance.

EdTheHeaterMan · February 5

Sounds like you have a leaker just above the operating water line. the way you test for a leak above the water line is to put more water in the boiler until it gets to the top of the equalizer piping. Sounds like you already did that by accident back in December.

At the next emergency budget meeting, you need to bring up the subject under new business: purchase of a new boiler.

mattmia2 · February 5

You should find someone to install the new one that can figure out what system problems killed the old one too, they should last more than 15 years unless there are leaks in the system causing a lot of fresh water to be added or the piping is incorrect such that it is pulling the sections of the boiler apart.

EdTheHeaterMan · February 5

Actually as a temporary fix, you can try to use Boiler Solder to fix a leak above the water line. You get the boiler solder water mixture inside the boiler with the water line below the leak. Then you heat the boiler to make steam. Then you slowly add water to the boiler and continue to make steam. When the water level gets to the leak the boiler solder will fill the void and you will have a few months until you need to replace the boiler.

KconQueso · February 5

https://forum.heatinghelp.com/discussion/comment/1840493#Comment_1840493

I have a feeling there may possibly be an issue with the automatic water feeder. The water line in the gauge usually is low on the glass tube so I'm thinking it's feeding it more than it should… Of course, it might be something else.

mattmia2 · February 5

It only feeds if it is leaking out somewhere like through bad vents or leaking valves or piping or now though the hole in the boiler.

A little bit evaporates because it isn't a completely closed system but it should only lose a couple gallons a month or less.

Jamie Hall · February 5

I hope that the pressure comment was a typo — ">5 psi". I hope you meant "< 0.5" psi. But I'm not counting on it…

Check the cutout pressure of the system. If this is a residential or relatively small commercial system it should be less than 2 psig…

KconQueso · February 5

https://forum.heatinghelp.com/discussion/comment/1840495#Comment_1840495

Just so I got this right:

I add it to the boiler with some water (below the leak). I close it back up and turn it on. Then I slowly add water until it reaches the hole/crack. Then, presumably, the water will leak out of there and as it leaks, the solder will begin filling in the hole and seal it. Have I understood the process correctly?

My only question then would be: Where would it go in through? I'm assuming one of the pressure relief pipes? The plumber who came through said the Hercules would go through the 15psi pipe.

Also, is there anything I can do if it's a gasket? Like maybe something like this?:

https://www.amazon.com/Red-Devil-0897-Temperature-Silicone/dp/B008O0Y2Y8?th=1

KconQueso · February 5

https://forum.heatinghelp.com/discussion/comment/1840511#Comment_1840511

The plumber told me the boiler has 3 pressure points where it would shut down if pressure got too high—5, 10, and 15 psi. I just said under 5 because it's never gone beyond that. It's usually between 1-2 (though I have seen go a bit above that once in a blue moon).

EdTheHeaterMan · February 5

Correct description fo the Herculies boiler solder process.

Pour the power you mix with water into any opening that you can access. The skim tapping may have a larger opening but the relief valve opening is fine. Follow the instructions that comes with the product.

Trying to seal a leak from outside will be a exercise in futility.

Jamie Hall · February 5

The 0 and 15 may be sort of OK… as they are emergency backups.

The 5 is two and half to three times as high as is needed. Even the Empire State Building operates on 2 psi.

Send us a picture of the pressure control devices, and we can advise on how to fix the problem.

Won't help the leak now, though you will lose less water and less fuel (and money)…

yellowdog · February 6

Please don't allow that plumber back into your building.

Steamhead · February 6

@KconQueso , where are you located? We might know someone who can be more helpful……………

KconQueso · February 11

Hey all,

Apologies for not responding sooner. I wanted to monitor the situation a bit and read up a little more before I responded.

I shut off and opened up the top of the boiler top yesterday night to see if I could identify anything wrong and see if there was a hole or anything on the sections. I could not visually see anything. If there is a hole, it might be in the back which I haven't gotten to yet. If not, I'm gonna assume it's maybe a minor crack or pinhole.

I'm thinking of opening the top while it is operating to see if I can see where the steam is escaping from. Obviously I'll be careful regarding the heat. Steam quantity is still low so I'm not expecting a burst of steam to the face. Or maybe I can remove the top and let it run until steam comes out.

Also, when I opened it, i noticed there was a silver material that looked like dry paint that had completely crusted away. I've attached a pic. Is this a seal of some sort that needs to get repaired/repainted? Could that be where the heat is escaping from?

I lowered the heat to 69 to put less stress on the boiler but I still get instances where the pressure does climb. I have seen the pressure get near 5 before shutting down (which is not good). Am I right to assume that the leak is causing the boiler to run longer/hotter to get to the desired temperature causing the pressure to rise? Will finding the leak and sealing it stop the rise? The pics below were all taken at different times during operation.

20250208_194808.jpg

20250208_200553.jpg

20250208_120946.jpg

Finally, I think the cause of this may be either the known leak or possibly even a leak elsewhere in the system. I don't have a water meter to see how much water is added to the boiler but I do hear the automatic water feeder turn on here and there for a few seconds. Obviously there is a leak right now causing it to happen more often but I have no idea how long this might have been happening for.

If anyone can let me know about the silver paint, I would appreciate it. Haven't been able to find anything online.

I'll look at the back tonight and see what I can do over the next day or two to get this fixed (if possible).

mattmia2 · February 11

they gray stuff is furnace cement or possibly just mortar sealing the edge of the flue collector box, it seals from flue gases, not water.

The way to find the leak with the jacket off is to fill the boiler with water and look at where it is leaking. You can only see a small amount of the boiler with the sides of the jacket on and the collector box installed. you could look up around the burners (with the gas off) with a mirror or camera too, once you fill the boiler completely with water.

KconQueso · February 11

https://forum.heatinghelp.com/discussion/comment/1842002#Comment_1842002

Ok. I'm assuming I should still repair the gray stuff at some point. Possibly a high-temp sealant?

I'll try your suggestion which @EdTheHeaterMan also mentioned as well in the first post.

EdTheHeaterMan · February 11

You can remove all the silver/gray hardened high temperature cement and put a new coat on there. This is what I might use: 10 Oz. black furnace cement tube or Hercules 16 Oz. furnace cement. Both types are available locally at Hardware stores and big box stores. That will seal the flue collector box to the cast iron sections so that exhaust gasses do not leak into your home.

My earlier comment about Boiler Solder is used to seal pin holes and cracks in the boiler sections where water or steam can leak out of the pressure vessel from the inside by getting stuck in the leaks from the inside.

mattmia2 · February 11

The pressure is because the boiler makes more steam than the system it is connected to can condense (either because the boiler is oversized or some system problems are causing some of the system to not heat or they are turned off). It has little to do with the leak.

KconQueso · February 11

@edtheheaterman Since I never kept the water that high after the initial leak, I'm now hoping that when I fill the tank, the leak is below the maximum water line. If that's the case, could I use boiler liquid instead of solder? The main reason I'm asking because some online reviews claim it'll possibly stuff up pipes.

@mattmia2 This is a brand new symptom then of something else? It's never been an issue since we installed it so it's likely not an oversize issue. Besides checking everyone's radiator, what else could i check?

KconQueso · February 12

Good morning, folks.

First off, I'd like to thank everyone who has shared their wisdom and expertise in this discussion so far.

So, as I said above, last night while the boiler was working, I removed the top and saw where exactly the steam was coming from and peered into the boiler with my endoscopic camera. I saw what looked to be a small hole.

Then, I filled the boiler to the max water line and, lo and behold, I saw the water pour out. I can't tell if it's small enough for boiler sealant to patch up but I'll give it a try (what do I have to lose at this point?). At least it's below the water line.

Screenshot_20250212_084148_Gallery.jpg

Screenshot_20250212_084017_Gallery.jpg

Screenshot_20250212_084000_Gallery.jpg

If the sealant doesn't work, are there any other options to get me through the next month and a half or so? Maybe use a second bottle? Lower the heat to 68 (69 now—lowest I can put it is 68) to reduce gas usage and strain on the boiler?

Some people suggested patches but a lot of responses recommended against that because they said it might fail. Welding will probably be tough too even though the hole is in the front of the section. Are those all the options?

Also need to figure out why the pressure is going up. It's making more steam comes out and I'm starting to see condensation here and there.

Thanks again.

Steam coming out from behind the boiler...

Comments

Categories