Third floor is cold

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

@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)

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.

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 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.

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

@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.

After sleeping on it, I retract my wacky idea!

Please forgive me for the distraction....

Here is the trapped water evidence:

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