Third floor is cold

mattmia2

It looks like an almost new valve, the screw that holds the washer in place may have been loose from the factory.

foresthillsjd

@SteamingatMohawk here is the inside of the shutoff all the way open. 

I tried disconnecting the radiator and then timing how long it would take steam to come out after the other third floor radiator started getting steam.  It took three minutes. And while I was waiting, the sounds coming from the open pipe were a cross between a belch and chair being dragged on the floor.  It was actually reminiscent of my husband’s snoring at night:

https://share.icloud.com/photos/019eQBX8bZy4uZcp8C9FmjKAw

LS123

@foresthillsjd , I am not a pro but I used to get uneven heat destitution issues. I got some really good help from the forum....

Once you get the venting sorted out try things below.

1) Have an adjustable vents where your Nest Tstat at. ( I have two steam rads about 5 feet each in the living space area they get hot and reach the Tstat temp faster. I put one adjustable vents by the rad closer to the Tstat (kept it at lower vent settings. This help having rest of the house heat well including the room where the Tstat is at)

2) Have some research done why your boiler reach 1.5 psi cut off during heat cycle (unless I misunderstood your posting). Based on the boiler, burner a certified pro may be able to get the correct heat output level set for your boiler, rads etc...

* I have noticed... less or about 0.5 PSI seems to get my Rads fired up. Very seldom even after hours of continues run, reach 1.5 Max and Ptrol kick in.... (on a low gauge PSI - mine is Max 3 PSI on the pig tail, but there is a built in 0-30 PSI as well, this is a required PSI gauge to keep on all boilers as I understood, at least in the state where I live)

cross_skier

I am similar to @LS123.  Since running really low pressure, less than 0.1 psi, I am having no issues with radiators heating.  I got there by adding lots of vents on the mains/risers and adding 2 radiators.  It would take a very long time for my system to reach 1.5 psi.

Downfiring a bit may help you a lot

Lance

I beg to differ on steam pressure. At some point if your pressure is too low, distribution will lag. The longest run no matter if it is an open pipe, will still be the last to get heat. If the last room cools quicker than lower rooms, it will be the first to need heat. And no matter what, if the thermostat is satisfied and off, that room needing heat will cool first. Try one method to accomplish a longer burn time and quicker on time is to adjust the stat heat anticipator or reduce the heat output in the room with the thermostat. You have a balance issue not so much a pressure issue I believe. Any thermostat that satisfies too quickly due to a lamp, or a nearby fireplace, or over sized radiation in the room or a wrong anticipator setting in will make this problem.
Vapor stats at some low pressure point won't make enough steam, especially if steam mains are uninsulated! You must make steam at a rate faster than it condenses or you lose the pressure at the extremes. Sizing boilers and emitters is critical. Its a trade off. If we vent the mains too quick or unbalanced, we will not have pressure left over to push higher. Vent the mains for balance to the risers, vent the radiators for balance on the riser. One pipe / two pipe, steam trapped systems all require balancing to its design. Nothing behaves more differently between a low temp day and a high temp day than a steam system. In a sealed system of vapor, the pressure is equal all around, in a non sealed venting system the pressures reduce past each open vent point. And as we know all vents do not vent equally. Nor do all work equally. Air and steam balancing is an art that requires patience and experience. Like your car going up and down the hills, the accelerator changes accordingly to maintain a steady speed. I like steam because its a living breathing creature that is quiet when content and cantankerous when not.

LS123

Hello @Lance .... I agree with you on most... I am not sure if you suggesting that having less or about 0.5 PSI on a steam boiler is not enough steam PSI to get the rads screaming hot ..except the oil burner everything else in the house as old as they can be and still works.... and works so well!
Insulation of main lines in the basement, and the insulation of the basement, replacement of main vents, replacements of rad vents and having adjustable vent on rad closer to Tstat works SO well for me... I live in a considerably cold climate... use less than 10 hours of heat cycles in 24 hours.... that add up to give or take 7-9 gallons of fuel for 24 hours.... for me .... less or about 0.5 PSI definitely works on two story house with good size rads that are well balanced... I agree with you....sometimes it take a little bit of time to get everything to work in harmony with steam systems..... I would never change from steam

mattmia2

foresthillsjd said:

I tried disconnecting the radiator and then timing how long it would take steam to come out after the other third floor radiator started getting steam.  It took three minutes. And while I was waiting, the sounds coming from the open pipe were a cross between a belch and chair being dragged on the floor.  It was actually reminiscent of my husband’s snoring at night:

https://share.icloud.com/photos/019eQBX8bZy4uZcp8C9FmjKAw

There is water trapped in that runout to that radiator somewhere. When the steam hits the cold condensate trapped in the pipe it condenses. the steam won't make it past that point until it has heated that water. The solution is to figure out where that water is trapped and move the pipe to fix the pitch so it can drain back to the main.(could be in the main too if this is at the end of the main)

foresthillsjd

@LS123 and @cross_skier, I have my vaporstat set at .5 psi, and most every other radiator gets pretty hot at the same time.  

@mattmia2 I have a hunch about where the pipe is not pitched properly. it’s either in there middle of the main or the branch off of it.  But is it safe to say that if other radiators further down the main are heating okay, then it’s probably just the branch?  

It’s inside sheetrock, so I want to minimize the holes I cut. 

mattmia2

foresthillsjd said:

@mattmia2 I have a hunch about where the pipe is not pitched properly. it’s either in there middle of the main or the branch off of it.  But is it safe to say that if other radiators further down the main are heating okay, then it’s probably just the branch?  

It depends. If there truly are radiators that heat between it and the end of the main then it has to be in the runout somewhere. You have to figure out where the end of the main is. It could be that the main runs around the basement and returns at the boiler and the end is at that return at the boiler, or it could slope to a return at the far end of the basement and there may be 2 ends on either side of that return, or it could slope back to the boiler from some mid point toward the boiler or there could be branches that end at a vent in a couple places. The piping at the boiler might give some clues. Essentially there may effectively or actually be more than one end of the main so you'd have to know there are other radiators between the radiator that doesn't heat and the end of the main that do heat to conclude it isn't the slope of the main.

ethicalpaul

mattmia2 said:

There is water trapped in that runout to that radiator somewhere. When the steam hits the cold condensate trapped in the pipe it condenses. the steam won't make it past that point until it has heated that water. The solution is to figure out where that water is trapped and move the pipe to fix the pitch so it can drain back to the main.(could be in the main too if this is at the end of the main)

Just adding my voice to @mattmia2 who has it right. Forget venting for now. Until you find and fix this water trap, you will never be able to balance this radiator.

You can try running a long call for heat (maybe as much as an hour or more) with that pipe open to see if it is able to get hot enough that the water allows the steam to pass and/or becomes steam itself. This would help you verify what is happening here.

Basically there is no normal system that will be able to resist sending steam to a radiator with a size D vent on it. If your radiator doesn't get steam with that large of a vent, it has to be for a reason. Your reason is there is water in that pipe.

I had the same problem in my bedroom radiator and I ended up having to run a new riser to it.

dopey27177

On the radiator shown near the bottom of the radiator it appears to have a plugged tapping. If so remove the plug and insert the vent valve in that location.

Jake

SteamingatMohawk

The valve looks fine. As noted above, the problem seems to be in the riser. I looked back at your sketch and it is the second radiator from the boiler on that main. To what extent have you been able to observe the pitch of the riser from the main?

A crude test would be to connect a plastic bag of some sort to the riser and blow into it to see if there is any resistance to the air. It might tell you if the pipe has a portion that is full (acting like a sink trap of sorts) or just some residual water that slows down the steam or no detectable flow resistance. Don't try using a fan, shop vac or leaf blower, just a good set of lungs.

foresthillsjd

@SteamingatMohawk interesting idea. so I take a small plastic bag, and put it on the riser, and blow into it like I’m trying to inflate it inside the riser?  And how will I know the difference between water completely blocking a pipe and just residual water?

SteamingatMohawk

Not quite, the bag is just so you don't have to put your mouth on the piping. I was going to say a tube, but decided against it. When you blow into the bag, it will try to move air inside the pipe and you may be able to tell a difference between an unobstructed pipe and one with a buildup, whether it's water or sludge. If it is easier, you could just put some tape on the pipe and blow on it directly.

I realize it is a bit of a wacky idea (I like that kind of speculation at times) that might give you some worthwhile information. The worst that can happen is you waste a plastic bag and some tape. Hopefully, you won't pass out from blowing too hard into the pipe.

archibald tuttle

@edebratt

foresthillsjd said:

EBEBRATT-Ed said:

Venting the risers is discussed in the LAOSH as removing the 90 deg radiator valve and installing a tee with a riser vent on it and reconnecting the radiator with a straight radiator valve. Frank Gerrity's method

I must have missed that part when I was reading. In NYC, I'm so used to seeing those vents like what @cross_skier posted that that's what I always assumed venting the risers was...

I am with edebratt on the tee at the top of the rise. I'm assuming from looking at the subject radiator, if i'm referring to the right picture, that you would replace the angle valve with a tee and then add a straight format valve out of the branch so you don't need to raise the radiator up so much as you were thinking as move it over slightly.

From what I read it sounds like this is the only rad on the third floor which is notable, if you had others they would potentially be venting the same riser although it might be larger so more air to vent.

Can't tell from the triple vent on the main in the basement where the riser to the third floor takes off relative to other radiator feeds or how big it is and the valve is obscured at the rad, is it 1" or 1 & 1/4" ?

Also, there does look to be a relatively low boss on the end of the radiator with a bit of depression that could be drilled and tapped so the vent could be moved lower. with raditator sections like that in a two pipe would actually feed the top connection on one end and then vent from the bottom connection on the other end. actually, as i look at the similar casting at the top could it be there is a flush plug in a tapped hole. the top one looks hex. the bottom one, the angle of view and the paint makes it difficult to assess. or, it wouldn't be out of the question to pull the larger plug at the bottom and bush that connection down. (appropros of another thread on getting something apart I would use a 4 or 8 point socket for that. worth the investment.)

In the NFN department, after all that, I would tend to confirm it is venting problem by just pulling the vent altogether and running a cycle to see that it vents quickly and even if the steam won't fill all the sections you should get heat into a section or two reasonably quickly by comparison to a standard cycle with the vent in place. once you get significant escaping steam you can just shut off the radiator valve before the test turns into a wallpaper stripper.

mattmia2

It doesn't have to be blocked with condensate, just a significant puddle would do it because it would cool the steam and condense it in to water at that point, probably rather violently

SteamingatMohawk

After sleeping on it, I retract my wacky idea!

Please forgive me for the distraction....

archibald tuttle

mattmia2 said:

It doesn't have to be blocked with condensate, just a significant puddle would do it because it would cool the steam and condense it in to water at that point, probably rather violently

I missed the second page of comments, but I had thought of trapped water but with no knocking or noise reported had discounted. And, IIRC, this problem cropped up, or became more noticable, when the pressure was reduced which doesn't necessarily correspond to excess condensing over cold pool. Given that you have to heat a lot of unisulated steel riser I would think it would need to be a fair quantity of trapped water to make such a difference, vs. venting. But this goes back to my first rule of thumb. If the radiator is slow, pull the vent out and see if the steam comes right to it, or, with the radiator removed if you open the valve and get steam relatively quickly that suggests a tee at the top of the riser to like a 3/4" main vent would be helpful. If, on the other hand, it is slow to steam even to an open valve then I would be more prone to suspect some kind of water trap.

But maybe there is something in the verbiage of symptoms or just your statistical experience that suggests trapped water over trapped air?

ethicalpaul

Here is the trapped water evidence:

https://forum.heatinghelp.com/discussion/comment/1685700/#Comment_1685700

archibald tuttle

ethicalpaul said:

Here is the trapped water evidence:

https://forum.heatinghelp.com/discussion/comment/1685700/#Comment_1685700

missed that. absolutely, she already ran the test i was suggesting. 3 minutes with valve open and belching before steam, i'm with you. the whole thing makes more sense now. stand down from the venting til a low spot is found. (although that post also slightly confuses me because I thought before there was only one radiator on the 3rd floor which can make sense in a mansard circumstance with limited finished space as you go up to the top floor. Saw this first in verbiage but then in referring to the diagram from this comment)

if there is only one riser to the third floor as depicted on the diagram and one radiator is filling fast and the other isn't that narrows the search for the problem, but i wonder if the diagram missed a riser or missed that one of the 2nd floor risers has a continuation to the third for that other radiator.