Still Having Main Venting Imbalance

Jeff_53 · November 2005

Also to thfurnitureguy, I made a map of my system (I hope it makes sense) to see if you can help me better understand what you mean about short circuiting in a steam system.

Jeff_53 · November 2005

My one pipe steam system has two mains: a slightly shorter main 46 feet and a longer 54 feet. I have the shorter main vented with two Hoffman 75's and the longer main is vented with a Gorton #2. I just added a second Gorton #2 to the longer main (per Steamhead's suggestion). And while the distribution seems a little better the rads at the end of the long main are still getting little, if any, steam.

I was sure that adding the second Gorton #2 would solve this imbalance. I have new vents on all the rads (maid - o mist) with various venting speeds based on the size of the rads. Generally, the rads closest to the boiler get more steam than those farther away.

The shorter main (with the Hoffmans) supplies four rads and the longer main (with the Gorton's) supplies six rads.

What am I missing? What's the next step?

As always, any feedback is most appreciated.

Steamhead (in transit) · November 2005

Hmmmmm

Something is keeping the steam from going into that long main. Are you sure all the piping supplying the main is as it should be, properly sized and pitched?

Might be time to call in a pro. Try the Find a Professional page of this site.

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jim_72 · November 2005

Boiler cycles?

Quick question guys. Today stat was programmed to make 72 degrees at 5 PM. Just prior to 5PM house was 71 degrees. At 5PM boiler starts runs for 20 mins. I check stat and temp reads 72 degrees yet boiler continues to cycle 2mins on 1min off.Ifthe stat setting has been reached why does the boiler keep cycleing? Stat is honeywell 3600 digital.Thanks Jack

Jeff_53 · November 2005

Thanks Steamhead,

That's just the trouble, I have called a pro (a couple) and in my area (Rochester, NY) no one is calling me back. I guess they're all busy. And there are no pros in my area on the 'find a pro' section of Dan's site.

I'm going to look at the pitch of the long main and see
if there are any irregularites. Also, I asked this a while ago, but the near the boiler piping is not correct. (I've posted a pic.)

Thanks again for all your help.

gerry gill · November 2005

perhaps put slower

vents on the radiators that heat up well, and bigger vents on the slower rads..also, is the pitch of the radiators themselves okay?

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gerry gill · November 2005

ouch, thats

certainly piped bad.

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Jeff_53 · November 2005

Oh, I should also say that on long burning cycles (like in the morning) all the rads heat up nice and hot. It's the shorter cycles where the balance problems occur.

Steamhead (in transit) · November 2005

Maybe

the thermostat is causing the unit to short-cycle. What type do you have?

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Jeff_53 · November 2005

The Thermostat is a Honeywell T-87. It was installed a few years ago and is level, etc. I've done some experimenting and concluded that the shorter main with the Hoffman's ALWAYS gets hot faster. The Hoffman's shut after about 4 1/2 minutes. The Gortons close after about 8 1/2 minutes. I've checked the pitch of the mains and it's all good. There are no broken straps or visible low spots. The system runs quiet except for some 'ticking' in one of the upstairs risers.

Still trying to get a pro to call me back but in the mean time am trying to educate myself. This has me stumped!

Fred Harwood · November 2005

balance

> The Thermostat is a Honeywell T-87. It was

> installed a few years ago and is level, etc.

> I've done some experimenting and concluded that

> the shorter main with the Hoffman's ALWAYS gets

> hot faster. The Hoffman's shut after about 4 1/2

> minutes. The Gortons close after about 8 1/2

> minutes. I've checked the pitch of the mains and

> it's all good. There are no broken straps or

> visible low spots. The system runs quiet except

> for some 'ticking' in one of the upstairs

> risers.

>

> Still trying to get a pro to call me

> back but in the mean time am trying to educate

> myself. This has me stumped!

Fred Harwood · November 2005

Balance

May I assume that the second main from the boiler is the hard to heat one?

thfurnitureguy_4 · November 2005

Returns

Jeff, Are the returns on the slow side wet? and is there any radiator that can short circuit back to the main vent? what I mean is, can steam go from the radiator back to the main vent up the return without hitting a steam trap or a wet return?

jeff_57 · November 2005

In response to Fred Harwood, the main that is hard to vent is the one that comes off the TOP of the header (see photo posted a few messages above). I know that the piping around the boiler is wrong. Both main risers are piped BETWEEN
the risers that come off the boiler and I wonder if this is the cause of the problem. Also, two of the largest radiators that come off the slow main are close to the boiler and they seem to get hot before the Gorton vents close.

Jeff_53 · November 2005

To Thfurnitureguy,

As far as I can tell the mains on the slow side are not
wet (no spitting from the rad vents). I'm not sure I understand your comment about a radiator short circuiting the system. This is a one pipe system (no steam traps).

thfurnitureguy_4 · November 2005

It is picture time. Take a picture where your main vents are and let me see the connection where the main becomes the return. Do the two mains drop into a wet return at this point? Are they seperate as they go into the wet return? If they gang together and then drop into the return you have a problem. Please re-size your pictures. A wet return is a type of return and not a bad thing. anywhere your return is below the water leavel of your boiler is a wet return. IE it stays full of water. It also stops steam from going past this point. I think your problem is at your connection to the return where your main vents are.

Jeff_53 · November 2005

Drip Connection

I don't have a digital camera but I've made a drawing
by hand showing the 'maping' of the drip conncetions and how they connect to the mains.

Thanks for your help.

thfurnitureguy_4 · November 2005

Jeff your drawing didn't show up. is your set up like in the "pipes" drawing I posted or like the "wrong" drawing I'm posting now.

gerry gill · November 2005

do the radiators on the fast side

get steam before the main on the slow side gets steam through out? if so, try slowing down the venting of the fast radiators so they don't condense steam and create a vacuum which will be a lower pressure zone than the higher ''atmospheric'' pressure of the gorton vented zones..i guess what i'm saying is that if your the steam, and there is a vacuum on path ''a'' and a gazillion gorton vents on path ''b'', but venting only to atmosperic pressure, your still going to the vacuum side cause its easier..

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Jeff_53 · November 2005

Another picture attempt

I did my best to create a drawing that represents the drip connection piping on my system.

Jeff_53 · November 2005

More Detail

Thfurnitureguy,

I just looked at both your drawings and have a better understanding of what you're suggesting. I've modified my drawing giving more detail. I do notice that both the drip connections that come of the mains are very hot when the steam is on. Is this an indicator that this segment of my system is piped incorrectly?

Thanks for all you help. BTW, what type of computer program do you use to make your good drawings?

thfurnitureguy_4 · November 2005

Jeff, I must be a computer spaz. but I still can't get your picture. I use Paint for simple diagrams. just outline the final picture and save as whatever so it is not poster size when you post. It is normal for the pipes at the return to be hot, they have fresh condensate water running through them and won't be as hot as steam but still hot to the touch. Follow the path of steam down the main pipe to the vent. Once it hits the vent where does it go? Does it have to go to a wet return or is there any path it can take toward the other vent?

John S. · November 2005

try...

removing one of the Hoffmans. just for kicks.

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jeff_57 · November 2005

jeff_57 · November 2005

Thfurnitureguy,

Sorry about my bad computer skills. I've found a digital camera and will
take some photos later today. Also, per your question, yes the drip connections are ganged together. The fast side drops straight into the wet return and the slow side is piped into the fast side's direct drop.

As you said, air must get trapped. This makes sense because on long heat cycles (in the morning), the rads at the end FINALLY get heat. (The air must eventually get released through the rad vents instead of the main vents.) But on short cycles, the air prevents the steam from getting out in this section of the system.

thfurnitureguy_4 · November 2005

This must be a popular retrofit. I had the same set up It drove me crazy. I kept adding vents and it did no good. After the steam on the fast side closed the vent it went right past and closed the vents on the slow side. I left all the air trapped and no heat to a whole side of my building. Drip that main with the Gortons into the wet return and see what happens. Ask Steamhead he found my problems, and gave some real solutions. best of luck

John S. · November 2005

Hi Jeff,

If the slow heating main ties in to the drip of the fast heating main ABOVE the water line, that could very well be the problem. Drip the slow main directly into a point well below the waterline.

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Jeff_53 · November 2005

Finally have a picture

Here's a pic of the drip connections on my system.

thfurnitureguy_4 · November 2005

Is there another main behind the shelf?

Steamhead (in transit) · November 2005

Yes there is, Tom

if you look wayyy up you can see two Gorton #2 vents. Jeff has the same problem you did. I turned up the brightness, try this view.

Fortunately, it will be easy to take those pipes apart and lower the horizontal portion below the waterline. Just look at all those unions.....

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Jeff_53 · November 2005

Thanks All

Thanks for all your help on this. The drip connection on the left goes straight into the wet return and connected by an elbow. My thought is to replace the elbow with a 'T' fitting and extend the wet return until is is directly under the right drip connection. Does this make sense? Also, I'm a little concerned about getting the elbow off the bottom of the drip. Can I heat the old fitting? And, I assume that there will be water in the single drip up to the level of the waterline. Will this be the case?

Thanks again for all your help. I'll report back when the problem is fixed.

Still Having Main Venting Imbalance

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