Balance/venting problem?

Tom S.

Today I put a Gorton #4 on the cold baseboard (didn't want it to vent too fast and make too much condensate) and then shut off - as much as I could anyway - all radiators/baseboards on the hot main.

Cold main again heated in about 20 minutes, and the cold baseboard got hot in about 25 or so minutes. Of course the big main gets hot in 5-8 minutes! And, FWIW, the pipes leading up to the cold main got hot reasonably fast but it hung up for 5+ minutes at the "T" where the piping comes into the cold main.

I will replace the vents on the hot side that I can for now (some are bb and will need some surgery to fit anything other than a varivalve).

I might also try a Gorton 5 or 6 on the cold baseboard to see if that speeds things up without speeding too much.

Hope that sounds right, I welcome vent choice suggestions. I have in my possession one each of Gorton 4,5,6 and the 4 is on the cold bb now.

Tom

Tom S.

Cold Main...

I just had a new Burnham IN4 (steam) installed by a pro from the 'find a pro' list. He is coming back later this week to help troubleshoot a problem. I'm trying to learn more in preparation for that visit.

Generally, I'm very pleased so far, except that I'm having a problem with one of my two mains not heating, or at least not heating until very far into a long burn, and then with some water hammer.

If you can see the pic below, you'll see a 2" main heading off to the right (20+ feet), which heats all but one radiator (some are bb steam, some are radiators). And a 1 1/2" main heading left (10+ feet), which heats a single section of bb steam. It is this left section that will NOT get hot until well into a long burn (45 minutes or so). The cold pipes are labeled in blue in the pic below. If/when that main (and the cold pipes) gets hot, it has water hammer going on. There is a Hoffman vent near the end of that left-side shorter main, on a riser. When it eventually does start venting (45 mins), it seems the water gets in there and it spurts hot water up like a little fountain for about 5 minutes and eventually closes.

The pipes are pitched correctly - the smaller 1 1/2" main back toward the boiler, the bigger main away from the boiler because it has a dry return.

The bigger main has a Hoffman vent on the dry return (just out of the picture), near the boiler. That doesn't vent too much because it would seem most of the venting is happening upstairs in the living room (lots of huffing at the beginning of a heating cycle). That vent is a varivalve and it is mostly open.

I have read some posts that a fully open varivalve vents enough to throw things off balance.

The boiler doesn't build up very much pressure - when we're at that 45 minute mark, the pressure is around 1.5 psi (hard to give an accurate reading with a 0-30 psi gauge). I don't think it's cut out on pressure ever (set to 1.5 cut out, 0.5 cut in).

As a temporary fix, I've lowered my night setback some so the burns aren't that long and therefore the left smaller main doesn't get hot and doesn't hammer, but that's not a solution, since the one main/bb gets no heat.

So, the questions:

-is this all about venting and balance or is there something else going on here.

-should I close the varivalve way down?

-can I/should I have my professional tap into the end of the big main (see pic) to add a gorton vent and will that help?

-is there anything I'm missing here?

Appreciate any help.

Tom

Ted_4

It looks like

there is a piping error here. The connection to the smaller 1-1/2 inch main looks wonky. Why was it piped that way? I think there is a counter flow issue here that is preventing condensate from leaving the main. Both mains should pitch away from the boiler, and be vented and dripped at the end, just like the larger main is. Perhaps your contractor thought the radiator vent would be enough venting for this main, and condensate would slide backwards through the main to the drip at the boiler, but it's not working right. On start-up this main is forced to handle condensate from both the radiation and the cold main which is being held back by the steam flowing the other way. The lack of heat and the water hammer are a logical result of this arrangement.

Tom S.

Let me..

make sure I understand, and make sure I give you all the info...

My 1 1/2" main (heads off to the left) has a vent on it, towards the end (not shown) which spits water. There is no dry return and the pipe is pitched back to the boiler.

My 2" main (heads off to the right) has a dry return, and the vent is not at the end of the main but back near the boiler on the dry return (pic of end of main w/o vent above).

With the old boiler, the boiler piping went up from the boiler to a single main that went the whole length and there was only the dry return main vent. The new boiler has the header and splits into two mains (both vented). The old piping worked fine, both sides got hot - it was only the one main.

I would've thought that the smaller main (left side) would've at least gotten hot from condensate pretty fast, despite the lack of dry return?

Would a dry return on the smaller main (left) solve this problem?

Thanks again for your thoughts-

Tom

John S.

Tom S.

A few things I would check...

1. how much of a pitch does the short main have?
2. how much baseboard radiation is attached to it and is the size of the main enough to handle that much?
3. What direction and amount of pitch is on the baseboard radiation?

Ideally the baseboard should be pitched AWAY from the main, with a return pipe off the other end that drips into a wet return or forms a water seal at the floor and rises back up to the main.

Try this: turn off the baseboard that's not heating. let the boiler now run a cycle. Does the main get hot fast now? If so, you'll have to deal with that baseboard. If not, it would seem to be a pitch problem.

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Tom S.

Thanks for the ideas.

The baseboard that the main is supporting is only single pipe (no return)and it is about 6 feet. I know that is taboo, but it is what it is. It is pitched back towards the supply. I am not against replacing it with a proper radiator if need be.

I have turned off the baseboard that isn't heating (it's been off for a week or so now), and the short main does not get hot unless the boiler runs for 45+ minutes and then you get the spitting/water hammer in the main vent/short main.

I don't think it is the baseboard that is the issue here as it is closed but the main does not get hot.

I haven't tried removing the main vent from the short main and running the boiler to see what happens then (if steam will get to that end fast).

I will check the pitch of the short main, how much pitch should it have?

Tom

John S.

left my copy of TLAOSH

at work so I don't recall. Might be as much as 1" in 10'

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John S.

just noticed a potential problem

the drip off the back of the short main should (seems to me) be placed on the other side of the tee. As it looks right now, the condensate is trying to come back and 'pass' the down-fed steam supply which is headed the other way.

That's all I've got!



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gerry gill

take the vent off the cold main

and report back..does steam get there quick with the vent off?

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Tom S.

Took the main vent off...

Took the main vent off the smaller main, didn't make a difference. After the boiler started steaming, the big main (right side in pic above) gets hot right away, but the smaller main (left) stays cool. After about 10 minutes, the small main is hot at the "T" (marked HOT below) and maybe 4-6 inches also along the main to the left and also to the elbow to the right(a few inches too), but that's it. The down drip pipe to the right of that stays cool too (marked COOL below).

And one correction - it is a vent-rite vent, not a hoffman. But, that really doesn't seem to be the issue anyway.

Appreciate any thoughts.

Thanks,

Tom

Steamhead (in transit)

Check the pitch of that main

Something is keeping the steam from traveling thru the main to the vent- probably a low point with water standing in it. It should pitch at least 1 inch in 10 feet toward the boiler if there is no drip at the very end near the vent.

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gerry gill

okay...can you slow the venting down

on the fast sides main and radiators? backpressure the other side some is where i'm going with this..without seeing it, it sort of sounds like so much venting on one main that the steam goes there first, starts condensing, this drops the area to negative pressure, more steam goes that way, and the other side at atmosheric pressure can't compete against the vacuum..

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John S.

what size pipe

is that drip on the short main?

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John H.

Blocked main

All the piping looks new.
Hi pressure to low always. unless the line is blocked.
Maby with a rag or something els durring the install.
Take loose the dripper and look down the run.

John H.

Blocked main

sorry out of order
All the piping looks new.
Hi pressure to low always. unless the line is blocked.
Maby with a rag or something els durring the install.
Take loose the dripper and look down the run.

Tom S.

That pipe

has an outside diameter of 1 5/16", which (I guess) makes it a 1" pipe?

Tom

Tom S.

Okay, more soon..

My installer pro is coming tomorrow night, so I will print this out and discuss with him.

I will try closing all the vents on the fast main and see if that has any effect.

I keep thinking about a rag or something in there, so hopefully we can look tomorrow night...

I will also check the pitch, although a casual check with the level shows it is pitched toward the boiler. I'll have to remove some insulation and look more carefully.

More info as it happens, and THANKS for all the help.

Tom

Tom S.

Pitch seems okay...

Pitch on the small main seems okay - it's not dramatic but it seems to meet the 1" in 10 feet requirement.

I also closed the vents on the 5 radiators the big main serves, which didn't change the situation (4 of these vents are varivalves, which generally work well for me even though the radiators still get hot with the vents "closed", only slower).

My pro couldn't make it tonight, so I have no other news, but I'll keep you all informed.

Once again, thanks for your help and ideas.

Tom

gerry gill

can you draw a sketch and post it here

of how your short main is piped..from start to end of radiator..include vents, pipe reductions (sizes) all pertinent data..

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John S.

Hi Gerry,

Could there be a potential problem if the main vent on that main were lower than the down-feeding supply pipe to that main? Hope that makes sense.



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Tom S.

here's a pic

I think I have it all right in the picture below- I left out the detail of the long (working) main.

The near boiler piping is better shown in the very top pic in this thread.

No change in size on the main.

The drawing is not to scale.

There is a riser and a main vent off of the big main's dry return - left that out by mistake. It's right near the boiler.

Thanks,

Tom

---

The Riser that goes to the (cold) bb - seems to be all the same size right up until it disappears up into the wall.

---

Edit (1/5/06): in the interest of accuracy, I corrected the drawing below. There was an error in the return pipes to the boiler. (not that it matters as all is working well now).

brucewo1b

I am no steamhead but I wonder if the steam is having a hard time fighting the condensate in the 1.25 main. I could see it if the return came off at cap then the codensate would be flowing in the same direction and not fightin the staem. Just a thought.

Long Beach Ed

This installer...

went through a lot of trouble to pipe this thing right. It appears to be a well though out and neat job. He even used American (Ward) fittings, which are quite superior and much more costly than the Chinese junk I see on many jobs today.

But it's not working, eh?

I've always hoped I'd find a rag in an elbow but never did.

You say that even with the vent removed, the short main doesn't heat? Wow.

Either...

The water is backing out of the boiler, up the drip to the short main, flooding it... or

There is a water pocket in the short main... or

The boiler is too small or not firing properly or all the oil from that nice threaded pipe is making the boiler water foam and it just ain't producin' enough steam and has to be cleaned.

Otherwise, the job looks beautiful.

Long Beach Ed

gerry gill

no john, that shouldn't matter...

overhead drops from the attic have the vents in the basements..

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gerry gill

configuration looks correct..

not sure i like the idea of a main smaller than 2'' tho..has this boiler been cleaned? skimmed? drained, flushed, skimmed again? just for my peace of mind, instead of closing off the varivents, close all the radiator inlet valves on the heating main, take the vent off the slow main and see if steam goes there then..is there a vent on the baseboard?

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Tom S.

I will...

I will try closing the radiators (2) but there are 3 baseboards that have no inlet valves so the best I can do is close the varivents.

That'll have to be after work today though.

It does need to be skimmed again as there is some bouncing in the sight glass. I don't know that it's been drained/flushed though, at least it hasn't since install (a few weeks back).

There is a vent (varivent) on the cold baseboard. Wide open.

Will report back tonight.

Thanks,

Tom

Tom S.

Thanks..

for the reassurances that things look right. It probably does need to be skimmed as there is some bouncing in the site glass.

I don't think it is backing up from the boiler, only because that drip pipe does not get hot and I would assume that it would from boiler water (bad assumption?)

I don't think I'm undersized - I had two estimates, both sized it as an IN4 and my own EDR calc put it there too, although I don't trust my own calcs!

Thanks for the ideas,

Tom

Dan C.

Ted

The smaller main is vented and from what I understand that is the correct way to connect to a counterflow main. You haven't seen the whole job and you probably shouldn't be making assumptions about what the contractor might have thought a comment like that could make a homeowner think that he hired someone unqualified. I installed the boiler and I am going back wednsday. I have a very good idea of what the problem is and I am going to take care of it.

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Dan C.

thank you ed



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Long Beach Ed

That Unheating Baseboard

Now I'd never try to tell a plumber who does such beautiful work anything, but looking at this one has piqued my interest.

That entire 10 foot main only serves one length of baseboard?

In case nobody ever told you, baseboard is notoriously hard to heat with steam. It's simply too narrow to shed the water. Did this ever heat? Yea, I know, it heated fine until you came along with that boiler of yours.

The new boiler emits steam at a MUCH higher velocity than the old one did. This means there's more push of steam keeping the counterflowing water up in the baseboard. It either doesn't heat or spits water out of its vent.

The baseboard needs a hard pitch. If I had a ten-foot baseboard, I'd pitch it up about a half a foot. Yea, I know, it will look stupid. But it isn't exactily art if it doesn't heat. The size of the runout and valve is also critical. You see, you must get the condensate to return against that typhoon of steam.

Now if all this is a problem, drip the far end of the baseboard to a wet return and the counterflow is gone. And while you're at it, cut out all that old iron main and runouts that aren't doing anything but robbing heat. Hay, money's no object when it comes to making that basement a steam heating beauty.

But I'm sure Dan C. will solve your problem. Anyone who still uses Ward fittings really cares about his customers.

Long Beach Ed

Bob W._3

Good thought about the skimming. My experience is that doing it once after the install is not enough. Those oils and the dirt will keep coming down into the boiler for awhile.

Tom S.

Like I said, I'm very pleased with Dan's installation, and it's always good to hear confirmation of that from other professionals.

As Dan mentioned, he's coming on Wed. to have a look. I am confident it will be figured out.

I mentioned above that I'm not against ripping out the baseboard and putting in a radiator if necessary (I inherited this heating system, baseboards and all, when i bought the house). If it ends up spitting water, that's what I'll do. A return won't happen as this is all on the second floor.

Regardless of that issue, though, I'd have expected this short main to heat up some, at least until the main vent closed!

I am going to try Gerry's thing about closing radiator inlet valves tomorrow, just for my (and his) curiousity. I will report back.

Tom

Tom S.

Okay, today I closed the radiator inlet valves (2) and shut the varivalve air vents on the baseboards (no inlet valves on them).

Ran it and the smaller main heated up in 20 minutes instead of 45+ minutes. I went upstairs and most of the "shut" radiators/baseboards had some heat in them (radiators hot 25% across, lower than normal). So much for working inlet valves! The baseboards with closed varivalves did get hot some too, but that's always been the case even when they are "shut".

Anyway, the smaller main did get hot faster (20 min). The bigger main was hot after about 5 minutes.

There was some spitting at the main vent on the smaller main too.

I realized that I had the air vent of the cold baseboard off the smaller main plugged (to prevent any hammer I figured), so after that 20 minutes I took the plug out and put the varivalve vent in. That led to a lot of banging because I was obviously condensing a lot of steam too fast, so I need to run the whole test again with the vent in place before I start.

And, yes, I know it can be dangerous to pull the vent off when the boiler is steaming and I won't do that again! Thankfully I had enough time to swap the plug for the vent this time.

Will try it all again tomorrow with the vent in place.

Tom

gerry gill

i'm thinking that

you may need to install slower vents on the fast heating side, something like gorton 6's or hoffman 40's..and vent the slow main faster..don't vent that slow side baseboard to fast or it will spit also..the spitting on the slow side main vent causes me some concern..i'd think a gorton 2 main vent on the slow main would be good..

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Tom S.

Thanks Gerry - will discuss with Dan when he comes on Wednesday. Unfortunately, I don't think the baseboards can fit anything but a varivalve as the vent is housed in the end of the baseboard under a cover and the varivalves are pretty small and fit nicely.

Will report results with vent in place tomorrow eve.

Again, thanks for all your thoughts/ideas/analysis.

Happy new year,

Tom

gerry gill

Tom, let me tell you about a steam war story..

i had two radiators in two adjacent rooms being fed steam from a common riser pipe..okay, common vertical feed pipe, has two branches just a couple feet each one going one way, the other going the other way..mirror images, okay..picturing this now? okay, both radiators heated, but slowly..being the advocate of faster venting that i am, i proceeded to put heatimer varivalves on both radiators..guess what happened..one heated 100% all the way, scorching hot..you could of cooked steak on this radiator..the adjacent radiator was ice cold..you know, the cold that only cast iron can achieve..now remember they worked till i touched them..you can imagine what my face looked like...being the advocate of fast venting and all...so it took me awhile to figure out what was happening..the steam in its wisdom chose a path that only it could deduce was the path of least resistance..it then was vented so heavily that it ''plowed'' into the radiator of least resistance and of course started to condense..this heavy condensing was creating a vacuum that enticed more steam to follow..i took the radiator vent off the cold radiator and couldn't get steam to go into it...see even without the vent, it was still at atmospheric pressure while the hot radiator was in a partial vacuum....i took the varivents off and put on gorton c's....guess what..all well and both heat evenly...now its still considerably faster than the garbage vents that were there, so i found my limit on that installation....i'm thinking you have a similar issue...i'd replace those varivents with something smaller..


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Long Beach Ed

Gerry - Ever think of this?

That radiator of least resistance was heating, condensing and drawing a hard vacuum. But it was easier for it to suck air through the connector from radiator #2's vent than to suck more steam out of the main.

Wonder if that Varivalve #2 was sucking instead of blowing?

Fun, this stuff, eh?

Ed

gerry gill

it may have been..

thats possible..wouldn't it be really interesting to have a test lab with glass radiators and a method of inducing a colored smoke into the steam to see what happens when different things are done to the radiators and piping...john shea had emailed me a picture of warren websters test lab a while ago..was real cool..

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Tom S.

That makes sense to me...the working big main is pulling a vacuum from the condensing steam, keeping the smaller main steam-free. And the experiment of shutting down the larger main today showed that the smaller one will heat if given the chance.

I still have an issue with fitting anything but a varivalve in the bb radiators, but perhaps having them "closed", which still seems to let some steam in, may be slow enough venting to make this work.

Funny, it may well all come back to the actual title of this thread - balancing/venting....

Will try again tomorrow afternoon.

Tom

gerry gill

you know Ed, thats a very good point..

the low pressure zone of the hot radiator definitly was drawing more steam into it..cause it was screaming hot..but it being the point of lowest pressure had to have sucked in from the other air vent, since the atmospheric pressure was now in essence a point of high pressure..it was definitly an interesting learning experiance..

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gerry gill

what kind of baseboard do you have?

cast iron, steel, copper? can you pipe an 1/8th inch elbow in up to a hole drilled in the cover and a chrome vertical hoffman installed? being chrome it wouldn't look bad..

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