Residential Steam boiler

delta595

Ok guys, looking for some advice here. I'm in a single family house,2 stories. I have ( 1 )radiator on the second floor. It does nothing but bang, then shoot about 2 gallons of water out of he air vent before getting hot. I checked everything. Boiler pressure is cycling off the pressure controller at about 1 1/2 psi. Every other radiator works perfectly. All radiator valves are wide open. I actually changed all vents to vari-vents. Obviously, this is the last radiator to get hot. It's riser from the basement is in the middle of the horizontal header. Any ideas?? Could there be a clog in the riser? why won't the condensate return from that riser?

JUGHNE

Is the rad sloped to drain back to the valve?
If so then you could raise up both ends maybe a 1/2" and then more on the vent end.
This may raise the pipe under the floor that may have water in it.

Or even if the valve is completely open the washer could have fallen off the bottom of the stem and partially plugging the pipe. Steam comes in OK.... but no condensate draining freely out.
If valve will not come apart easily then disconnect the valve union and slide the rad away to see inside the valve outlet.

delta595

thanks, I also forgot to list it. I changed the valve. Pitch is perfect. I never seen this in my entire career. The amount of water shooting out of the radiator vent is crazy. Any more ideas.

EBEBRATT-Ed

How steady is the boiler water line when it is steaming? Doses it move more than an inch or so?


How about some pics of the boiler and the piping around it. Is the steam piping parallel or counterflow? How is the main venting?

delta595

Water line goes down a little but it’s steaming up- no surging at all. All vents are new vari-vents. Only got pic of radiator spewing out water.

EBEBRATT-Ed

@delta595

Are you getting any water hammer or just water? Sounds like a pipe is not pitched as @JUGHNE mentioned

delta595

Radiator is as high as piping will allow. Great pitch toward the valve as per my level. Violent hammer with water spewing out of vent.

EBEBRATT-Ed

If your getting hammer you have a pipe with a dip in it somewhere, maybe concealed. Maybe a pipe hanger came loose.

The only thing you can try is to vent it slower, I know it's the top floor

Water in that pipe that's not draining is cooling the steam causing it to condense (1700 x it's volume in water), new steam rushes into the vacuum that;s caused and that gives you hammer. I would guess if the water is coming out the vent that the low spot isn't too far from the rad. Just a guess

delta595

I would post a video of the radiator in action but it won’t let me.

MilanD

Does the radiator sag, perhaps the middle is somehow bowed?

MilanD

Did you use a steam valve or water? Steam one has a larger bonnet and a larger opening from water one. Did it bang before all the work you did?

Jamie Hall

Violent hammer isn't in the radiator -- it's in the pipe leading to it. The water spewing out is the water that was banging and has finally been beaten hard enough to get there. Somewhere, probably quite close to the radiator (although it could be as much as a floor below), there is a pipe which is pitched wrong.

delta595

Thanks, it is a steam valve. As per the banging you are correct. It is in the riser coming up. That’s why I thought possibly a blockage, just enough to let steam by after the pressure builds up. From the horizontal header in the basement it comes off the bull of a tee pointing straight up to the second floor. At the point of the second floor it’s less than 2 feet to the radiator. No way I’m holding almost 2 gallons of water in 2 feet of 1 inch pipe. Any other ideas?

MilanD

You say that this radiator riser goes straight up from the main? Well, that's perhaps your problem...

Condensate and steam have no way of passing one another. You are getting a shower of condensate falling down while steam is rushing up. It's pickling up the water and banging it around, possibly also collapsing some of the steam to add to the 🎉 party!

You didn't answer if this is a recent development or if this particular radiator always banged. 

ethicalpaul

Two Gallons of water shooting out of a vent...I wouldn’t be so quick to eliminate surging as a cause. 

delta595

85 year old single family house. It’s a single pipe steam system. All the other risers are fine except this one 

EBEBRATT-Ed

@delta595

If the riser truly comes up straight off the main and the tee looks straight up the steam and water cant pass each other as @MilanD mentioned. That could make it hammer

There is a reason 1 pipe steam the take offs have to be made (in most cases) with a tee laying in a 45 and then a 45 elbow. The water slides back on the bottom of the pipe and the steam travels through the top. If this is true the problem may be in the basement and can be fixed with some creative piping

Also, you mentioned 1" pipe. 1" can't do much more than a small radiator. Check the eDR of the radiator against the pipe size

delta595

Ebebratt exactly what I was saying. It is a small radiator as well. I really believe somehow that tee in the basement is clogged partially not allowing all the water to return. What do you think?thanks again 

Jamie Hall

If it's really two gallon per cycle, it's coming from somewhere other than the riser -- or the radiator.

The riser you mention will hold a total of one quart of water, assuming it's full. That quart of water will have a pressure of 10 psi at the bottom, and your boiler won't produce enough pressure to push that column of water anywhere, even if there is no plunger or piston or plug to hold the water in there.

If we suppose for a minute that the water you're seeing is all condensed in the radiator before it comes out -- all at once -- you will have had to condense about 60,000 BTU worth of steam. That's a lot of heat -- the radiator would be more than toasty warm.

LS123

@delta595 , Do you have adjustable air vent valves on your steam radiators? There was a post several days ago... I tried to find it but could not... I remember in that discussion posted was keep getting water or lots of hammering... he had adjustable air vents on steam radiators... that person open ( or set all the valves to be at highest possible air vent... it seems like it has fixed his issue. I am suspecting in that posting.. perhaps defected adjustable air vert valve on steam radiator was not allowing all the water go back to return (single pipe)... not sure if you are facing the same issue... I thought I share this info with you and all..

ethicalpaul

Air vents don’t prevent nor allow water to exit the radiator unless there is some problem with the valve, such as it being mostly closed or its disc is lying in the seat area

LS123

agreed... I was referring to an old post slimier issue (assuming the poster has adjustable air vent valves, that can become defective over the time)

LS123

@ethicalpaul , I had recently replaced old beat up undersized main air vent that was pushing out steam, I probably have lost about 2 gallons over 24 hrs... replace it with gorton 2... I no longer lose water on my steam boiler anywhere near... now I can run the boiler... its been about 5 days, avg temp 28F day... probably much lower over night.. 20F... I have not had tyo put water on on steam boiler.... I also had a steam radiator vent that was spitting out wet steam... literally, there was enough steam and ( wet steam) ... not like this post (no water from the radiator vents) I am wondering if the original poster has automatic water feeder in place and somehow ... its contributing to flooding ... just a thought ... I no not anywhere experienced as some of the posters who have responded ... but troubleshooting and process of elimination .. I am good at ... when I know enough...

ethicalpaul

It is possible for an overfilled boiler to shoot water out of the radiator vents for sure, but that's not what I suspect here. The poster reports otherwise normal operation, and that wouldn't be the case if their system were flooded like that.

If it were flooding like that the report would be more like "My gauge glass is full and water is shooting out of my radiator vents!" It's quite a traumatic experience Plus this radiator is on the 2nd floor, and if it were flooded, all the first floor radiators would be shooting water first.

If it were just a little water getting shot out of the vent, I would be looking toward something like radiator/supply pitch or slightly wet steam, or aggressive radiator venting, something like that. And it could still be a pitch problem, especially if two gallons was an exaggeration

But if it really is a gallon or two of water, I'd be looking real hard at the near boiler piping to see if it is incorrect and allowing carryover. Even though it's only reportedly happening in one radiator. The layout of the mains can direct carryover to one specific radiator sometimes. The poster describes that the riser for this radiator is coming out of the center of the boiler's header, and for one kind of common piping error, with a steam supply feeding both ends of a header, it can push water to the center of the header, which can get carried right up to the radiator(s) on this line.

@delta595 may we see photos of your boiler from about 10 feet away showing from floor to ceiling and maybe from a couple angles? Then you can potentially shut me up talking about carryover

delta595

Ok, back to the Original problem. Whether it is 2 quarts or 2 gallons I shouldn’t have water on the second floor of a steam system. Once the bi metal in the air vent heats and closes the radiator should be hot. I have new cari vents throughout the system, I tried mostly closed and full open- on the air vent, still on every cycle same problem.

ethicalpaul

Of course you shouldn't have water on the second floor. Everyone agrees on that. But for us to help you find the cause of the water, we have to determine where the water is coming from. If it's a quart or pint, it might be coming from a sag in your radiator supply pipe. If it's really two gallons, I would be looking to the boiler.

The fact that you've experimented with radiator vent rate (which is a good thing to have done!) tends to remove vent rate as a cause which makes me want to look at your near boiler piping even more.

delta595

ethical paul, i'm not at the house right now but I'll sketch it and poster a picture

MilanD

delta595 said:

Ok, back to the Original problem. Whether it is 2 quarts or 2 gallons I shouldn’t have water on the second floor of a steam system. Once the bi metal in the air vent heats and closes the radiator should be hot. I have new cari vents throughout the system, I tried mostly closed and full open- on the air vent, still on every cycle same problem.

So you never answered my orig questions...

Anyhow, if your riser carries water up the pipe due to conditions mentioned earlier, dirt and debris can lodge itself in the valve preventing it from closing.

delta595

sketch

ethicalpaul

delta595 said:

ethical paul, i'm not at the house right now but I'll sketch it and poster a picture

Thanks. A photo of the boiler at your convenience would be great too, but I think I can already tell that I will say that your near boiler piping is sending water up to your radiator like a coffee percolator. This is what @MilanD is talking about also.

MilanD

MilanD said:

delta595 said:

Ok, back to the Original problem. Whether it is 2 quarts or 2 gallons I shouldn’t have water on the second floor of a steam system. Once the bi metal in the air vent heats and closes the radiator should be hot. I have new cari vents throughout the system, I tried mostly closed and full open- on the air vent, still on every cycle same problem.

So you never answered my orig questions...

Anyhow, if your riser carries water up the pipe due to conditions mentioned earlier, dirt and debris can lodge itself in the valve preventing it from closing.

Also, if the water is shooting up like a geyser, the only condition this happens in, outside feed pump flooding the system, is water from the  condensed steam not being able to return back down and new steam rising pushing it out of the air vent, like a surringe. So, there is obstruction to water draining from the radiator. Did You try slowing down the vent on just that one radiator?  

delta595

there is no obstruction at the radiator. I removed the radiator and checked. I even opened the valve while the system was running with no radiator in place. All I got was lots of banging and hot water shooting out. The vari vent is brand new and tried all settings- same effect just and different time intervals.

delta595

I'm starting to think I'm looking at a blockage- steam can pass but water can't return properly. What do you think??

MilanD

delta595 said:

there is no obstruction at the radiator. I removed the radiator and checked. I even opened the valve while the system was running with no radiator in place. All I got was lots of banging and hot water shooting out. The vari vent is brand new and tried all settings- same effect just and different time intervals.

Well, this is new info. You can now definitively state that condition is on the riser and/or connection to main. 

When you say riser goes "straight to the radiator",  are there swing joints? There must be. They may be hidden under the floor. Did you attempt to raise the radiator while still attached to the supply valve? Perhaps 1/8 inch is all that will take to get the water pooling in that riser, wherever it many be, to drain back. Houses settle, joists bow, radiators dig into the floor, floors get replaced and change hights...  

MilanD

And as a general rule, steam pipes never ever build deposits. Steam is distilled water after all, and the velocity of it actually scrubs them clean... Wet returns are a different story. As is pitting in pipes, or pin hole leaks where water always sitts,  like a sag corner on a 90 el 

JUGHNE

Perhaps washer/disc from previous valve fell down the pipe and is hung up on 90/nipple acting like a check valve.
Sewer snake or camera may find something.

delta595

Thanks Milan. Yep, did that too. When the radiator was disconnected there was a little play in the valve. so I jacked up the radiator. when it was reconnected all the play was taken up, then I repitched it toward the valve. Still same problem. I understand the whole distilled water aspect but I thinking the riser is small and maybe something dislodged off the cast radiator and is stuck in a fitting. I running out of ideas!!

delta595

Also, if something was in the main, especially water, the system should push it back to the wet return. All the other radiators downstream are good. After the other radiators get warm this one starts banging, shooting hot water then steam comes. That's where my mind is going.

ethicalpaul

There is no blockage, I'd bet my boiler on it.

Here's what can happen that most people never see:

https://www.youtube.com/watch?v=Si-FoRQVIpA&feature=emb_logo

delta595

EthicalPaul….Thanks, Great video. So how do I stop it from happening?

ethicalpaul

It may require some repiping near your boiler, but we won't have a real good idea of if that's required until we see a photo or two. There might be a couple other small adjustments you could make that would reduce or eliminate it but the photo will tell us a lot.