Uneven house heat. One leg (main pipe) of the system heats much faster than the other

Robbbbb · February 2018

How do I get both sides of my house to be the same temperature? It’s more than I can accomplish with the radiator air vent sizes. Let me explain...

-it’s a one pipe steam system

-the boiler has 2 main pipes coming out of the boiler that obviously serve the steam down the line, plus there are 2 return pipes. I’m focusing here on the 2 legs that bring steam to different areas of the house. Each pipe serves a different part of the house.

-“Hot Leg 1” gets hot as soon as the boiler fires up. The heat moves along that pipe along the basement ceiling quickly. I can run my hand along the 30 feet of exposed pipe and feel the high heat moving along until it disappears into the ceiling

-“Cold leg 2” gets Hot very slowly. When leg 1 has 30 feet of very hot pipe, leg 2 is hot only 6 feet from the boiler and is slooooowly moving along its own 30 foot length. Leg 1 gets hot in under 5 minutes while leg 2 takes 10 minutes or More

- the radiators served by leg 1 get hot fast. Leg 2 radiators get Hot slowly. And since leg 1 radiators are near the thermostadt, the heat sometimes goes off before the leg 2 radiators get fully Hot, or sometimes not Hot at all.

- For radiator air vents, I’ve put the smallest size Gorton #4, 5, and 6 air vents on leg 1 radiators to balance the rooms and also try to slow the steam flow in favor of leg 2. I’ve put Gorton D on all leg 2 radiators.

-one strange thing. Even when leg 2’s main pipe is hot only a few feet from the boiler, and still stone cold down the line, two of the radiators on that line start to get warm warm. Shouldn’t the pipe be hot before the radiator gets hot?

-the main air valves above the boiler... I had a Gorton #1 on each leg. I tried to vent leg 2 faster by installing a Gorton #2 Valve on it, leaving the #1 on leg 1. No benefit,

-one More variable... most of the radiators on leg 2 are from an addition we put on the old house. The contractor used copper baseboards, which don’t retain heat well. So those rooms have always cooled down more quickly. But it’s worse now. I can’t even get the 2 sections of the house to the right temp to begin with. Section 1 will hit 75 and section 2 will stop at 68.

-the only thing that’s changed in the system. Maybe it’s a coincidence. The problem I’m having became more noticeable after a main air valve problem. We had a return problem one day where water was not getting back to the boiler properly and it was shutting GW down due to low water. I called the guy who installed the boiler 4 years ago and he quickly replaced the main air valves. This fixed the return problem immediately. I also recently flushed the last foot of the return line and noticed it was mucked up. These are not wet returns, by the way. I also clean the boiler will colloid and the leave-in chemical every year. No surging is noticeable and the water is pretty clear.

the_donut · February 2018

Pictures would be helpful of near boiler, vents, radiators and end of mains. Are you sure the returns aren’t wet?

Main vents on a 1 pipe should be a couple feet behind the end of main near the drop to return. You are only venting the distance from the boiler to the mains above boiler. You are not venting the 60’ of mains past the #1 and #2. Doesn’t matter how fast you vent the few feet by the boiler.

The radiator vents are venting the mains.

Install vents near end of main. Also pipe insulation will help. Stone cold pipes will condense water quickly forming a vacuum pulling more steam. Insulating will reduce heat loss and condensation in main.

Jamie Hall · February 2018

First, let's be very sure this is one pipe steam. Each radiator or baseboard unit has one pipe entering it, at the bottom on one end, and a vent?

Now in one pipe steam it is essential that the ends of the mains have ample venting. Are there any vents on the ends of the mains? How big are the mains (length and diameter)? How big are the main vents?

Is this parallel flow or counterflow? In parallel flow, the mains slope down away from the boiler, and have a drip at the distant end which connects back to the boiler through a wet return. In counterflow, the mains slope down towards the boiler, and have a drip quite near the boiler which connects to the wet return to the boiler.

Now -- you mention that you had a return line gunked up and that it was not a wet return. Ah... what is it? What does it connect to at each end? What feeds into it along the way? Dry returns and steam mains do, very occasionally, get "gunked up" but, since water never sits in them to have them do that is very rare indeed.

I think we need some near boiler pictures and a sketch of the whole system.

In the meantime, three things. First, insulate those steam mains. Second, install main vents at or near the ends of them -- as I say, let us know the size and material and we can help size them. Third, slow the vents on the side getting hot faster.

Robbbbb · February 2018

Jamie- thanks for the response.

It is one pipe for sure.
The main vents are Gorton 1 and maid o mist 15 which I’m told are the same. I uploaded pics... the whole boiler front and side, the mains and the air valves, the return that gunned up (spigot with new red handle),

The vents on the hot side are variavales set at the lowest setting on the slider. I also tried a Gorton 6 and the rad was a bit hotter

I know I should insulate in the basement but it’s a nice finished space so I’m being stubborn. It’s been uninsulated for years and this issue is new

I thought a wet return ran along the floor. Mine is in the ceiling and slopes towards the boiler.

nicholas bonham-carter · February 2018

Your supply piping from the boiler is not configured according to the explicit instructions from the manufacturer. Having the risers on both sides of the header with the takeoffs in the middle with no real equalizer is bound to throw huge amounts of water up into the mains., strangling the steam.
The lack of adequate main venting at the ends of the mains, (dry returns) prevents air from getting out of the mains so steam can get in. You are probably burning excess amounts of fuel (double?), to squeeeeeeze the air out of the constpated little openings of the radiator vents, a task for which they were never designed.
If you refer to the instruction manual, maybe you can compare what you have to the required piping.
What is your pressure? Has the boiler been serviced since the installation, with the pigtail cleaned?
Get some capacious main vents such as Big Mouths on the ends of the mains, and keep your pressure down below 1.5 psi, verified with a low pressure gauge, (0-3 psi). While the installer is doing that, ask him why he didn’t follow the instructions, so as to prevent a problem with the warranty when the boiler expires in a couple of years.—NBC

the_donut · February 2018

Radiator vents are for venting radiators. Increasing radiator venting is no substitute for main venting.

Heat timer Varivales are a niche product for hard to heat radiators. Sometimes the adjustment fails and stays pretty wide open. Using them on every radiator causes steam to prefer the fast vented close radiators (lower pressure) over the slower vented farther ones (higher pressure). Larger radiators will create a vacuum when steam hits the cold iron and collapses to 1/1700 it's original size. These radiators will continue pulling steam until the vacuum is reduced (radiator is hot).

Change the hot side radiator vents to a less aggressive vent like a Hoffman 1A or a ventrite adjustable vent and set them slow based on radiator size (not location) and increase the main venting to a barnes and Jones big mouth.

Ita also possible that the MoM vent orifice has water partially obstructing vent.

Robbbbb · February 2018

Thanks, guys. A few notes...
-The pressure is .5 and 1.5
- I recently tried a Gorton 2 on the left main, replacing the Gorton 1. It seemed to have no effect in terms of faster heat to that side. Should I buy 2 of the Big Mouth you mentioned? Would I install on both mains or just the colder one? How does it compare to the Gorton 1 and 2?
- I can replace the MOM with a Gorton but that is the hot leg of the system. Do you think it’s stuck open?
- I can replace all the variavalves with standard gortons
- The incorrect piping is a big problem. Does that make all of the other adjustments a waste of time?

Thanks

Jamie Hall · February 2018

When things are as chaotic as this, you almost always have a number of different problems interacting, and it can be difficult to separate them out. The only way to do it is to take it one step at a time.

So... I suppose if it were dumped in my lap, the first thing I would do is to make a sketch of the whole system, from the boiler risers right on through to the Hartford Loop. All the mains, all the returns (dry and wet if you have both), all the runouts and radiators, slope of all the lines, locations of all the vents. That's going to take some time, but it's worth doing.

Then I think I would study the near boiler piping. Can the steam move smoothly from the boiler risers to the header? Do the steam mains take off to the building after the risers? Does the header slope down from the risers to the equalizer? Are things the right sizes? If I found problems there, I'd have to figure out whether the problems were serious enough to correct. As it is, I really can't tell under the insulation what's doing what.

Then the next thing would be to reduce all the radiator vents to something reasonable -- say Hoffman 1As.

Then I would look at the mains and main venting. You have one side which stays cold, or certainly doesn't heat as well. If the main vent on that side is adequate, and you need to go along the main and find out where the steam is stopping. If this system is parallel flow, pay particular attention to where the condensate is going -- it has to drain freely. Your objective is going to be to get the mains so that they both heat at the same time, or as close to it as possible. Until you do that, there is absolutely no point in playing with the radiators.

Insulate the mains. But please do it with fit for the purpose steam main insulation, not that fiberglass wrap stuff from the big box...

BobC · February 2018

i suspect the near boiler piping is causing all kinds of issues can you take a picture from a different angle so we can see exactly how the pipes coming from the boiler are tying into the boiler header and steam mains?

Also are both mains sloped so water can find it's way back to the boiler, make sure there are do dips where water can settle - that can lead to steam condensing and not making it to the radiators.

Bob

Robbbbb · February 2018

Bob- are the pics in my prior posts OK or should I take a few more?

Fred · February 2018

I honestly don't know where that near boiler piping is going? The Utica is a side tapped boiler but it looks like there are three pipes on the right side of that boiler, one of which is from the side boiler tapping, the other two that tee off of it , where do they go? It appears somewhere towards the floor. The pipe on the left, I assume was intended to be the equalizer but if it is, the header is pitched the wrong way, or maybe that pipe is just a drop from a dry return? You need to take all that mess off of those pipes so we can actually see what is going on. It will need to be repiped, correctly so that wrap will have to come off anyway. BTW, those side tapped boilers should almost always use the tapping on both sides of the boiler.
Also, have you clocked the gas meter, with just the boiler running to see if that boiler is even getting the gas flow/pressure it should?

BobC · February 2018

The last picture above shows piping coming from the right side steam output of the boiler through a short header that feeds the steam main but the other end of that short main appears to be going down to the return and thus acting as the equalizer. From the left side we have a pipe coming off the other steam return(?) going up to the steam main.

That is a Dunkirk style boiler and they are VERY fussy as to how they are piped. I think that piping could be a large part of the problems you are having with steam distribution.

If you look at the manual you will see how it should be piped. Both steam outputs should be used and they have to be the same diameter as the steam outlets. The two steam supplies come first and then the two connections to the mains and last a pipe turns down to the boiler return acting as the equalizer.

I think the installer tried to use the old boiler header but didn't get it right.

Bob

Robbbbb · February 2018

Yes, he did use the existing piping when he installed the new boiler. He installed essentially the same boiler. I guess he thought it would be OK to use the same piping.

So if I show him the installation instructions for that boiler, should he feel obligated to redo it? I suppose the installation was less expensive because he did not re-pipe it. So I'd be willing to pay for it... or some of it. Thoughts on that?

Jamie Hall · February 2018

Frankly, if your contract with the installer didn't specify that it would be piped in accordance with the manufacturer's instructions and diagrams... he's under no obligation to do so. He might do it out of good will. Then again, he might not...

I do think the near boiler piping may be part of your problems. I doubt very much that it's all of them.

Robbbbb · February 2018

Another note. The boiler is clean. I use the 2 step colloid every year and leave in a 2nd #2 bottle. But are there any advantages of more or additional cleaning? I was concerned by the sludged-up bottom pipe that I had to clean in January and the failed main air valve from November. May be a coincidence but the heating got more uneven after that November issue.

Here are a few more pictures of the boiler, and the image from the Utica manual. Very different for sure.

How else would a plumber install it if not in accordance with the manufactures instructions? Based on other experience? Or thinking that using the existing is good enough?

i

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Jamie Hall · February 2018

Oh dear. Well, on cleaning. The boiler may have never been properly skimmed, and in any event there should be nothing -- other than possibly SteamMaster for pH control -- in the boiler water.

On the piping. I'm still trying to figure out what pipe is doing what, but as near as I can make out you have no Hartford loop - though you do have a strange arrangement on the only riser in use -- you have only one riser. Etc.

Compare what you have to the nice diagrams you posted.

Robbbbb · February 2018

The installer said that he used a chemical that maid skimming unnecessary. If I have to skim it I can do it. I read about it and it’s simple enough.

I compared the diagram while standing in front of the boiler and it makes no sense. It does not match in any way

Fred · February 2018

He probably used something called Squick or comparable chemical. That needs to be flushed out of the system and a proper skim done. I think I would have the boiler properly piped before skimming as you will have to do it again after re-piping. It isn't right and needs correction. I also can't over emphasis making sure the boiler is getting the gas supply it needs to operate at it's designed output. If it's not, it won't produce the amount of steam it should and what steam it does produce will take the path of least resistance.

Robbbbb · February 2018

Thanks. I have a lot of info to go over with that plumber and a second opinion I’ve been considering

BobC · February 2018

I would empty the boiler (when it's cold or just warm) and then I would fill it and empty it again. the refill it to the normal water line. bring it up to steam ad see how it acts, if that second main heats better it indicates that a good skimming is needed because it will act up pretty quick if all the oils aren't out of the boiler water.

looking at the second set of pics it looks like that left hand pipe might just be a wet return not a second equalizer but I'm not 100% sure about that. take off the insulation to the near boiler piping so we can see what size pipe he used, if it's too small that is a problem and that style boiler rally does want both steam outlets used the way the second mfr picture shows.

When was this installed?

Bob

New England SteamWorks · February 2018

Those boilers with the side outlets are difficult to get to perform with steam when piped perfectly. Your guy missed perfect by a mile....

Robbbbb · February 2018

It was installed October 2015. I check that pipe size

Dan_NJ · February 2018

Robbbbb said:
Thanks. I have a lot of info to go over with that plumber and a second opinion I’ve been considering

Just like with the medical profession, if you let the guy #1 in on the fact that a second opinion is happening, and there's protest out of him, run from #1 and get a third opinion, and maybe a fourth for good measure.

Uneven house heat. One leg (main pipe) of the system heats much faster than the other

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