venting 1 pipe steam

morevintage

I have a 1 pipe steam system with a boiler that we replaced 10 years ago. I have read "We've got steam" book and read a lot of the discussion here and have been trying to figure out why the system runs so poorly. When the thermostat is set at 69, the heat in the farthest room from the boiler only reaches 62. Yesterday I had the 10 year old pipe vent under this cold room changed to a Gorton #2 and there hasn't been any change in temp. There is about 57' of pipe from the boiler to this cold room radiator. I know I still need to do some pipe insulating but I've slanted the radiator and put a new maid o mist D radiator vent on it. What else should I be doing?
Clorinda

gerry gill

Lots to consider here. Just for starters-a few
does the boiler have a hole in it?
is the water quality good?
Is steam already condensing in other radiators creating a low pressure point before steam gets to the far rad?
Are the radiators heating on the same runout?
Is the pipe in question traveling through a cold space?
If you shut other rads, does steam get to that cold rad (an experiment)?
What vents are on radiators that are heating?

lots to consider

nicholas bonham-carter

The Gorton 2 main vent is good for only about 20 feet of 2 inch pipe, so you may need a couple more in order for the steam to fill the mains first, and then travel up to the rads.
Improper boiler piping, or over pressure may be an additional cause, so post some pictures of your boiler and it’s piping, so we can advise.—NBC

morevintage

Thank you both for your suggestions.
I will try the test with shutting off the other rads today.
In the meantime I've taken pics of the boiler and the new Gorton #2. I didn't know a #2 is good for only 20'. I could use 2 more on an antler as I've seen in discussions here.

Fred

I would say main venting is likely your problem. One Gorton #2 isn't enough. Also, where does that 1.5" or 2" vertical pipe next to your vent go? If it's a riser and the radiator in question runs off of that pipe, you probably need a vent at the top of that riser as well.

acwagner

Does this problem radiator heat fully, partially, or not at all when the boiler runs? What about the other radiators--do all your other radiators heat up at the same time or do they heat up in a sequence closest to the boiler first and farthest last?

morevintage

It heats up partially, none of the radiators heat up fully. Are they supposed to heat up fully?
The ones with the shortest length of pipe heat up first. I've been trying to balance them with the radiator vents.
I'm starting to think that I need to at least double the number of Gorton #2s on the mains!

acwagner

They don't need to necessarily heat up fully. I just asked because if it did heat up fully and the room was too cold then that might be an indication the radiator couldn't keep up with the heat loss of that room. Doesn't sound like that is the case.

Ideally, all the radiators heat up approximately at the same time. That way one room doesn't overheat relative to other rooms. Having very generous main venting is a key step to accomplishing this.

Do you have other mains besides the one you describe, and are they vented? What kind of vents are you using on your radiators?

morevintage

There are 2 mains from the boiler. They both branch into "Y" shapes with 2 more mains making a total of 4 mains. The one I described above (main A) with the Gorton #2 is 57' from boiler to end but some of that distance is shared with another main (main . Main B is 40' from boiler to the end. This has no vent at the end.
The 2nd main from the boiler also divides at one point. One
main (main C) is 56' from boiler to end. This is a pic of its' vent.


The other section(main D) is 48' from boiler to end but some of that distance is shared with the main C. This is a pic of its' vent.


I hope this makes sense.
Thank you for your help.

Fred

You need vents on all four of those mains and much more than those Hoffman 75's. It takes two Hoffman 75's to equal one Gorton #2 and it takes about four 75's or two Gorton #2's to equal one Big Mouth. I would put at least one Big Mouth on each of the four mains.

Steamhead

I'd add a vent to Main B since part of that length also serves Main A. Can you post a pic of the end of Main B?

morevintage

This is the end of main B.

main A=57'
main B=40'
A and B share 23'

main C= 56'
main D= 48'
C and D share 33'

acwagner

As @Fred stated, try adding a Big Mouth vent at the end of each of the mains you already have a vent on. They're available on amazon:

https://www.amazon.com/Barnes-Jones-Big-Mouth-Vent/dp/B01F26P13C/ref=sr_1_1?ie=UTF8&qid=1512910957&sr=8-1&keywords=big+mouth+vent

If you combine the Gorton #2 and the two Hoffman 75's you already have on one antler that'll vent a little vaster than one of these, so you can reuse them all in one location.

It's hard to vent mains too much. Eventually you max out the tapping or your credit card.

There's a PDF you can buy on this site that lists all the venting rates of basically every vent ever made and a general approach to balancing your system using venting. I found it helpful when I balanced my system. Nonetheless, there's still some level of trial and error to this.

Also, I noticed most of your main pipes appear to be uninsulated. If you insulate them that will help get steam to the radiators faster and evenly. Focus on insulating the straight pipe sections first.

By the way, I saw the hand hewed joists in your photos. Is this an 19th Century farmhouse?

gerry gill

Vents are also available here on this site's store

https://heatinghelp.com/store/category/vents

morevintage

Thank you for your help.
I'm ordering the Big Mouth vents now.
Yes @acwagner it is an old farmhouse, the oldest section dates to 18th century.

morevintage

Update after 2 weeks...
My heating contractor replaced the Hoffman 75's on main C (56') & D (48') with 1 big mouth on each main.
Main B (40') had no vent and that got 1 big mouth.
Main A (57') had a new Gorton #2 & they added 2 more #2s.

It has not been very cold in NJ but here are the results.
Main C & D have sped up heating slightly.
Main B which is in a straight line from the boiler is lightning fast and this is the 1st time since we lived here (10 yrs) that we have had the room heated above 62.
Main A has had no change with 3 new #2s. I put a new rad vent supplied by the contractor-Gorton #5. They said that was the problem but there was no change. Then they said it must be a bad radiator, so last night we switched it out with one we know works but no change-it still is about 62 in the room. The pipes in the basement do get hot but not for long enough to heat up the room.
Any suggestions for what to do next with main A would be greatly appreciated.

gfrbrookline

Assuming you have a 3/4 tap I would put 3 big mouths on A and C, and 1 big mouth plus 1 Gorton #2 on B and D and checking for balance. You may need 2 big mouths on B and D. Just went through this with my system and spent a lot of time trying to maximize venting and balance heating. Also having ventrites #1's on the radiators to make them easily adjustable makes a huge difference. Also watch the Gorton's, I have had bad luck with them failing.

acwagner

What's the insulation situation on the mains? Some photos show insulation, others don't.

Jamie Hall

On the radiator which doesn't work properly -- check the pitch of all the pipes which lead to it, all the way from the main. They must be pitched enough to let condensate drain back to the main freely, and you may have a sag in the pipe or even a whole section pitched the wrong way. That will do it. Usually you'd get a water hammer from that, but not always.

And I have known older houses to sag a bit here and there...

Fred

A bad radiator? Unless it leaks or was for hot water only, or it is a long radiator and it has a sag in it, I don't know what would make it bad. I think he was out of ideas.
How warm is the room with the Thermostat in it? Many times if that room gets up to temp and satisfies the thermostat, it may do so before some or all of the other rooms do. If that's the case and the thermostat is very close to the radiator, consider moving the thermostat. If it is not close, make sure the vent on that radiator is slow enough to heat that room at the same rate as the problem room, then adjust the other vents accordingly if that makes other rooms to warm.

EBEBRATT-Ed

Maybe it's the picture but pic#2 showing the steam mains looks like it might be pitched back towards the boiler. Also the end of main "B" looks like a connection that might retain water.

Also, @morevintage at the end of main "B" please get that romex cable up off the steam line.

I am an electrician, can't help it!