Old Weil McLain issue

oldboiler

I'm a homeowner with a one pipe steam steam system driven by a beautiful Weil McLain, approx 60-70 yrs. old that I've lovingly maintained for the last 26 yrs. Recently, two second floor radiators started yelling (gurgling) and spitting at me, usually in the early morning after night recovery. I removed the old pressuretrol (which came over with Columbus), added a T with a new Honeywell on one side and a new pressure gauge on the other. Set it at 2lbs., changed a few radiator vents and the problem seems to be corrected. It ran nice and quietly after that. I then drained and flushed the boiler 3 times. While drained, I removed the 2 radiators upstairs and ran a hose into the pipes to try and flush the return, while the drain valve by the boiler was open. While flushing one radiator, the stream of water in the basement increased substantially from nothing before I started. While flushing the other, it didn't seem to increase as much as I thought it should. Now, 3 days later, the water level in the sight glass is still increasing about 3/4" to 1" every 6-8 hrs. I'm thinking the return may be partially blocked. I do not hear any water at all running from the feeder valve. Can I pour a bottle of white vinegar down that radiator pipe (while the boiler is drained), let it sit for a bit, and then try flushing again with a hose into the pipe? I really didn't want to bring someone in and start cutting pipes if I don't have to. Any suggestions on breaking a possible partial return blockage would be greatly appreciated. Water ph is approx 8. I've been using Kek or Steam Clean for the past many years and drain & flush about every 2-3 years. Thanks!

Jamie Hall

Does the water level keep on increasing? Or does it stop after a while? If it keeps on increasing, water is getting into the boiler from somewhere -- most likely the feeder valve; you wouldn't necessarily hear it, but it might show up as a colder than expected pipe (if your regular water is cold, of course!). On the other hand, if it stops after a while, there may still be a partial clog in one of the steam lines. Unlikely, but it does happen -- and usually in a wet return; steam lines themselves, and dry returns, rarely clog. It may not be where you expect it to be, and without going over the whole system with a rather suspicious eye I wouldn't be able to give you much more help.

I don't really think vinegar is going to help much, though. This won't be scale. Try just flushing again...

oldboiler

It's been 3 days and the level is still increasing. It's been warm, so the boiler has not been running. If I turn on the feeder valve, just the slightest bit, the it's very loud. But if I put my ear to the feeder pipe when it's closed I hear nothing at all. It seems like a lot of water for a feeder drip, which is all it would be. That's what's making me think partial clog in the wet return. I never thought to check if the feeder pipe is very cold, thanks, because the feed is cold water. Is there any harm in flushing water into the radiator pipe from the second floor? The water is remarkably clean in the boiler after draining and flushing for a 70 r. old system. Also, while running, the water level in the sight glass pushes up about 2-3" when the boiler first gets hot, then stays pretty stable at that level (bounces maybe 1/2" or so).

Jamie Hall

If it's still increasing after three days... it's not a clogged return. It's a very slight leak in the feeder valve -- unless... do you have a domestic hot water coil in that boiler?

oldboiler

Coming off the side of the boiler is what appears to me to be the old coil for domestic hot water, but it's not connected to anything anymore. The water level never did this before I flushed water down into the radiator pipe. It started increasing right after that. Could be a coincidence i guess. Maybe I'll wait a few more days and watch the level. If it's the return, it has to stop. If not, I'll change the valve. As long as it's not harmful, I would like to try flushing the pipe again, but if there's a clog, then the water will go into the dry return and the mains as well. Since it's the end of the heating season, I guess it would all drain back to the boiler eventually. Is there anything that you might know of that i can pour down the pipe to help break up a possible clog, maybe a bottle of boiler treatment? I was even thinking of natural enzymatic drain cleaner, then flushing again, but I don't know if that would harm anything.

Fred

Don't put any drain cleaners of any type in the system. Weil McLain boilers use a composite gasket between the boiler sections and you don't want to ruin those. Also, vinegar or anything else will likely smell for weeks after pouring it into the system. In all probability, as has been said, it is likely water leaking past the fill valve. Do you have any drain valves at the ends of the wet returns? If so, you could try to flush the wet returns out but I'm thinking after three days, it's likely the fill valve.

oldboiler

Thank you both. I will not use any natural drain cleaner. If I did pour vinegar in from the upstairs radiator pipe, I wasn't going to run the system until I flushed the pipes and drained the boiler again. I'll wait a few days and see what happens. I have a valve between the Hartford Loop and the boiler. That's what I had opened as I flushed the pipes from the upstairs. Is it harmful in any way to flush water into the upstairs radiator pipe in a one pipe system? The only reason I keep thinking clog is because this started happening exactly after I flushed water into the pipes. I guess it could be the feeder, but that would be a highly unlikely coincidence, but I guess anything is possible and I have surely seen stranger things.

bob_46

Fred said:

Don't put any drain cleaners of any type in the system. Weil McLain boilers use a composite gasket between the boiler sections and you don't want to ruin those. Also, vinegar or anything else will likely smell for weeks after pouring it into the system. In all probability, as has been said, it is likely water leaking past the fill valve. Do you have any drain valves at the ends of the wet returns? If so, you could try to flush the wet returns out but I'm thinking after three days, it's likely the fill valve.

Weil McLain didn't start making rubber band boilers until sometime in the 1980's. The OP says the boiler is 60 to 70 years old I'm sure it's push nipple.

oldboiler

Thanks Bob. Do you have any suggestion for something to pour in the radiator pipe that might help break up a partially clogged return? And yes, Betsy is as old as the hills.

Fred

History of Weil McLain Boilers. They used composite gaskets at least from the 1950's until the 70's when they changed to rubber to eliminate the asbestos. I would not put any drain cleaning chemicals in that boiler.
Excerpt:
People who worked with Weil-McLain products have said they frequently
handled asbestos products in the course of their work. Asbestos rope, for instance, was routinely used between Weil-McLain boiler sections; when this rope was cut, it released harmful asbestos dust into the air. Asbestos cement, too, was used to seal gaps between boiler sections, and air cell insulation used on boiler jackets often crumbled and released hazardous asbestos fibers. Gaskets made by the company are also thought to have contained asbestos as well.

In fact, all Weil-McLain’s sectional boilers used asbestos products from the 1950s through the 1970s, according to court testimony. Products made or used by Weil-McLain that are believed to have contained asbestos include, but are not limited to:

Dresser Asbestos Gaskets
l-Fired Boiler and Oil Heating Units with asbestos rope seals
Asbestos cement
Air cell insulation
Full Link: https://www.mesothelioma.com/asbestos-exposure/companies/weil-mclain-company.htm

Jamie Hall

In mild defence of Weil-McClain, they were by no means the only boiler -- or other company, for that matter -- to have used asbestos. Almost all high temperature insulation products did (ovens in you kitchen, for instance) as well as any number of other things -- brake linings and clutches in cars and machinery was a big one. The stuff works wonderfully well in such applications; there really is no good substitute. Pity that if you breathe enough of it it is harmful...

oldboiler

I'm sure the boiler under the jacket is wrapped with asbestos. With all respect, I would just ask if it would do any harm to flush hot water from the sink through a hose down into the upstairs radiator pipe to try and dislodge any partial clog if the feeder value is not the problem, and is there anything I can pour in to help it such as boiler treatment (Kek, Steam Clean, etc.). Thank you all again.

BobC

If water is flowing through a pipe ( even a sow trickle) at this time of year that pipe will be very cold. If the pipe that feeds water into the boiler is very cold there is water flowing through that pipe.

Bob

EBEBRATT-Ed

most every old boiler has asbestos. I started in "73" and you could still go into a supply house and by a bag of asbestos shorts, mix it with water and cover the pipe fittings with it.

Don't know exactly when they stopped selling it but if my memory is right I think it was about 1980 when we got the message that the stuff was bad. I would be pretty certain that that boiler has push nipples

Fred

@oldboiler You won't hurt anything by running water down the radiator pipe from that radiator, however, you need to keep in mind that if there is a clog, it either has to be in that one radiator run-out (which I doubt) or it has to be somewhere in the wet return for that main and that should cause problems with other radiators on that main as well.

oldboiler

Thank you all. The pipe from the feeder valve is not very cold. I truly think its a partial clog in the return. I'll wait a couple more days and see if it stops. if it does I'll flush the pipes again and use some boiler treatment. If the water level keeps increasing, I'll replace the feeder valve. Thanks again for everyone's help. I'll post back what the final issue was once figured out.

nicholas bonham-carter

Don't use any "boiler treatment", instead flush out the wet returns. This may involve installing some means to supply some pressure at one end of the wet returns, and an drain at the other end.
The dry returns, above the waterline are extremely unlikely to have any blockage, whereas the wets can be full of rust debris.
Keep the water feeder valves off for the near future, to see if the rise in water stops.--NBC

oldboiler

Thanks Nick. There is no way to get water into the mud leg without cutting the pipes. Theres a valve between the Hartford loop and the boiler, but no access on the other side other than a radiator pipe. I wasn't ready yet to have the pipes cut because they're behind basement walls. If I have to, I'll have pipes after I try the flushing. I'll post my results.

nicholas bonham-carter

If you had a tee and full port valve on the wet return before it enters the Hartford loop, you could fill the mains up to the basement ceiling, and then drain through that valve. The height of the water in the returns will increase the pressure, and hopefully flush any debris out.
When you do that don't forget to heat the remaining normal waterline water before closing down the boiler for the summer, driving out the oxygen.--NBC

oldboiler

Update: I just wanted to post my results on old Betsy. I flushed the mud leg again from the upstairs radiators and the water flowed freely and very clean. I changed the feeder valve and the water level has remained steady since. I refilled the boiler and added Rectorseal 8 way boiler treatment. Ph is good. I fired her up and she is whisper quiet. Everyone who said it was the feeder valve was correct. Thats why I came to this site, and to the pros. Thanks to all of you. Hopefully she will be ready next winter for another winter of great service. They surely don't make them like they used to. Thanks again to all of you for your help.