Hammering on newly installed boiler

arbalest

Thanks @Fred, I'll do that.

EBEBRATT-Ed

I thought from the pictures that the 3" main was pitched the wrong way but apparently it isn't.

It certainly won't hurt to drip that into a wet return. you don't need to make the drip 2" though but don't reduce on the horizontal.

a 2" x 3/4" reducing 90 installed on that nipple and a 3/4 drop is more than enough to drip that

arbalest

@EBEBRATT-Ed that sounds good.

There are two matching sized points down around the Hartford Loop already which look straight forward. One is a capped stub which I opened once to use a "wand" to rinse the interior. The other is at the bottom of the loop and has a drain valve on it currently.

If there is a contractor in the area (north side of Chicago) who is up for this please PM me. I know that most people are busy with bigger and higher paying jobs right now.

arbalest

Until I can have a pro turn that stub into a drip-to-the-return-side, I wanted to try my idea of putting a valve on it. I took the cap off and again, much less than a teaspoon of water came out. I put on a 90, a bushing, etc and a valve. Ran the boiler and briefly opened the valve with a bucket under it.

About 4 ounces of water came out, then just steam. I guess the pressure might have forced out some of the water that was in the main, but lower than the reducing elbow that this stub connects to. I would say then that making the stub into a drip leg is better than tilting the stub up a little, or removing that section and putting a cap on the reducing elbow. Better still, I guess, would be to have that main replaced (as others have suggested) with direct connections to the header.

Charlie from wmass

by opening the valve you allowed a false amount out of the pipe. split the elbow and cap the remaining nipple.

arbalest

@Charlie from wmass - I don't know what that means.

Fred

By opening the valve while the boiler was running, you allowed the pressure to push any and all condensate in that upper horizontal to blow out of the valve, not just what would have naturally gone into that stub.

ChrisJ

The stub isn't doing anything bad, in my opinion. Hard to say without being there in person.

Many don't understand steam and water can, and do get along as long as the water doesn't impede the flow.

For example..........look at your boiler. Sure is an awful lot of water in it, isn't there?

When water lays in a pipe or radiator and impedes the flow it causes very bad problems. There's no flow in that stub.

Look else were for your problem. I'd be concerned about poorly pitched pipes and or dirty boiler water.

JUGHNE

The stub is 2"?
The Tee is 3 x 2 x 3?
The stub is screwed into the concentric fitting of the 2" tee?

Would any cond drip water have to rise up 1" deep in the tee before running out of the 2"?

If the tee was flipped so the 2" pointed down then it seems it would drain cond........but redoing that piping...

Fred

I still don't believe that stub is an issue but as @Charlie from wmass says, if he wants to eliminate that issue, break the elbow and put a cap in the straight nipple.

Charlie from wmass

Sometimes we need to eliminate things that are not a problem but the consumer believes are a problem before we can move forward.

arbalest

@Charlie from wmass - it is not that I think it is the problem or the only problem. It is just the only thing I am able to do on my own right now. I thought I was clear on that. I cannot redo the main myself and I can't afford to have it done right now. I probably shouldn't try to turn the stub into a drip leg myself but I would have it done if I can find someone willing to do it affordably. I might be able to get the elbow off the stub myself but I am too afraid of causing damage that would force me to get the whole main redone -- (which I can't afford now) plus maybe go without heat for a few days.

So far I haven't been able to find a contractor interested in small jobs, or they are interested only if they can either turn it into a big job or charge me as if it is a big job.

To others out there - yes, I realize that opening that valve uses pressure to force out condensate that might be below the concentric leg of the reducing tee (if there is any). And turning that into a drip leg will do the same thing.

Also, I know that replacing the main with connections to the drop header will allow condensate to return to the drop header and get pushed into the return end of the drop header. I don't see why condensate from the radiators wouldn't just drain back all the way to the drop header now in the longer period between heat cycles. The pitch of things indicate that it should. Maybe it does drain all the way back.

Yes, I will do more skimming but during the heat cycles the water in the site glass is pretty steady (undulating rather than jumping around).

Charlie from wmass

@arbalest I fully understand your situation. I am not suggesting that you unscrew That Elbow. I am suggesting that you crack the elbow if you search on the wall there are many posts that explain how to use a grinder and a small chisel to split the elbow you can then move the cap to the nipple that is left in place. There are also threads on how to remove a pipe nipple from a fitting with a jab saw, a small hammer and a small chisel. I understand that you want to do something and this is something that you can do. The fact that your installer did not understand how to crack and remove a cast-iron fitting speaks volumes to his lack of experience with steam heating systems.

Fred

@arbalest , please understand that we are all trying to help you with the banging. That's the reason you came here; for some help. I appreciate that you are trying to do things yourself to keep cost down. What we are trying to explain to you is that, you can work yourself to death on any number of problems but if they aren't the source of the problem you are trying to fix, you are just exhausting yourself, emotionally and physically and you won't fix the problem (the banging)
- A teaspoon of water sitting in the stub won't cause hammer.
- a Drip leg added to the end of that stub won't act like the value you open because it will be dripped into a wet return where it won't be an open pipe to the atmosphere. It will be under the same pressure as the rest of the system. Steam takes the path of least resistance. That will continue to be the main vents and then the radiator vents.

arbalest

Okay, now I know what is meant by "split the elbow, or "crack the elbow".

I am afraid that with my luck I will get it to the point were it leaks but not be able to remove it completely. Murphy's Law is working over-time around here.

I am reposting two pictures posted above.The stub now has an elbow, a bushing and 3/4" valve. At the bottom of the loop there is a 3/4" valve for an occasional clean-out. I can handle piping between those two points especially since there are valves at each end. I can dry fit as long as it takes me to get it right. When it is fitted, with pipe dope and all tightened up I can open the valves. If it leaks I can close the valves again.

Is this point at the bottom of the loop an acceptable place to connect a drip leg like this?

Edit: I mean this as a temporary or exploratory thing. When the heating season is over I would attempt cracking/splitting that elbow myself. Or have someone else do it as part of a bigger project to get this right.

EBEBRATT-Ed

Do it. It may or may not fix your problem but can't hurt anything

arbalest

I will do this today. And I will put some insulation on the header pipes. I have some Mylar covered bubble wrap so I will start with that. I think fiberglass is better but I will do that later.

I want to add some new details here as well.

This is a three unit building. The first floor, where we live, has two radiators in the living room. For some reason, one day last week they both hammered. We noticed one leaking from just beyond the shut-off valve so I closed that valve (could the hammering cause that?). The remaining radiator still hammers sometimes -- not every cycle. Since no changes where made around the radiators (pitch, etc) and they are far from the boiler I wonder if this has something with venting. This is on the leg that had the Groton #2 that failed. At the time the hammering started I had already removed it and put the old vent back on. Now the new Groton is on there and the remaining radiator still hammers on some of the cycles. Today I will check the pitch on the radiator and replace the steam vent as it is "boiler day". Will probably do some skimming while I am at it.

Also, there is a pressure gauge on the boiler and above that a small gray box (Honeywell). I assume that sets the pressure and the sliding control is and always has been at the lowest setting. I added this info because of some other posts I have read here this morning.

Grallert

That bubble wrap will likely melt. Fiberglass is really the only insulation to use on steam pipes.

arbalest

Okay, it's been about a week since I connected the stub to the return side and mostly things have been quite. When it does hammer at all it is one thud rather than a series of klanks. That is still at the start of the cycle and it seems to be becoming more rare. The day after the modification I noticed that the overall water level was too high so I drained enough to bring it to the correct level and it has been fine since.

Now, what must be a separate problem, I have one radiator that hammers on occasion. That is seldom but it is a loud and persistent hammering that is a bit scary. Just now I shut off the heat while I investigate (it didn't seem to be going away on this cycle). Water level at the boiler is fine so it is localized to that radiator area.

Even though it is pitched properly I will add a bit more pitch today. I made sure the valve is wide open. If there is a steam trap somewhere around there it is between the floor and the basement ceiling. I don't see it.

Update: While investigating with the heat shut off, enough condensate has returned such that the water level is at the top of the site glass. So, I drained out a few gallons. I haven't insulated the near-boiler piping yet since I apparently have the wrong insulation. But with the proper piping (two risers, drop header, etc) can I still be sending wet steam into the system?

arbalest

Again, over the course of a few days the water level is slowly rising. I guess this means either:

a) the boiler is sending up wet steam in spite of the dual risers/drop header/etc or

b) it takes so long for condensate to return make-up water is automatically added.

c) any other possibility?

I don't know what corrective action would eliminate either. Maybe the risers should go to the full height of the ceiling before dropping to the header? But the header part is to spec already. Maybe there is a way to flush out what ever is slowing condensate return?

Fred

It's still water (condensate) that can't drain out of that upper horizontal 3" pipe. It has an elbow, up to the Main on one end and is reduced on the end that you put that drip leg on. As soon as steam hits that pooled water, in that pipe, it will hammer.

JUGHNE

Have you shut off the cold water feed to the boiler? And is that a good ball valve or an older gate/globe valve that might allow water to seep by?

Then being certain that your LWCO does in fact shut the fire down when water is drained out of the boiler, leave the boiler operate. You could time how long it takes the water level to return to normal as the condensate returns. And then go from there.

arbalest

@Fred - so condensate won't flow back through the non-reduced elbow part of the tee back to the header (then to the equalizer)?

@JUGHNE - there are new/good valves. I operate those when skimming and can confirm their operation. The LWCO does shut off the burner when it is adding make-up water. Okay, I will turn off the water supply, add tape to the site glass to mark levels and time the full return of condensate on the next cycle here.

Fred

@arbalest , From what I see of that upper horizontal, condensate will lay in that horizontal pipe, until that pipe fills high enough to spill into either the riser by the reduced pipe or the end of that pipe that you added the drip leg to. That's a lot of water to dump back down that riser to go back down the equalizer, especially since that pipe is uninsulated, causing more condensation. When steam hits it, it is going to hammer, if that water flows back into the flow of the steam. Shy of having that horizontal 3" pipe removed, the only other option I see is to have someone drill and tap that end of that horizontal, bottom side of that elbow and add a drip leg there that drops to the floor and into a wet return.

arbalest

@JUGHNE , when the heat cycle ended it took about 5 minutes for the water in the site glass to return to 80-85% of normal. Then an additional 5 minutes to get to the full 100%.

JUGHNE

I am thinking that you don't have that slow of a return, maybe an over active water fill that needs more delay.
If the boiler feed adds too much water and after firing the normal condensate water return giving you an overfilled boiler, then when next cycle comes along you are throwing water up and even have hammer in the boiler itself.
You have dry returns right to the boiler, so these should not have the issue of plugged/slow wet returns.

With the water off how long does the boiler stay off on LWCO before enough water returns naturally for restart?

Charlie from wmass

Drilling and tapping is not going to help drain that. The end of the pipe that you put in is going to be high enough to leave a puddle inside the pipe. Now if you can get a Victaulic high temperature saddle tap that might help

arbalest

JUGHNE said:

With the water off how long does the boiler stay off on LWCO before enough water returns naturally for restart?

I don't know how to set up an experiment to make that happen while I am watching. I'm not sure if the LWCO happens on a very long cycle or when there is a short time between cycles. It isn't every time a cycle runs.

I might be able to hang out in the basement tomorrow and wait for a shut-off to happen then start a timer and wait for a restart.

Maybe leaving the valve closed and manually adding make-up water, as needed, is the way to go for a while.

arbalest

JUGHNE said:

With the water off how long does the boiler stay off on LWCO before enough water returns naturally for restart?

Just now I happened to be nearby when the cut-off happened. The make-up solenoid opened (but no water due to the closed supply valve) and closed again in about a minute or two. Apparently by then it was warm enough by the thermostat such that the boiler didn't restart.

I think that just previously there was a cut-off followed by a second cycle that started before I could get the to basement (few minutes)

Much later, the next cycle wasn't long enough for the shut-off to occur.

It might be too soon to say, but since closing off the make-up supply I haven't noticed hammering.

arbalest

This entry is just to close this out once and for all.

The stub-to-equalizer hack got the hammering down to just a little. Closing off the valve to the LWCO feeder helped even more.

Even though I skimmed the heck out this thing last year it apparently needed more -- and then there was the extra pipe for the additional equalizer. Now the valve to the feeder is open and make-up water is only taken on once in a while. And most importantly -- I don't hear hammering anymore.

After the heating season I might remove the equalizer and try cracking away at the elbow with the stub. Then again, I may leave it all as-is until I can get a pro in here to remove the old header and tie all of the loops into the new header as has been suggested here.

So, a HUGE THANK YOU to all of you that have helped with this and... happy new year!

ratio

Thanks for the followup! It's good to hear about success (or at least heading in that direction) from time to time.