Steam radiator problem

Jeff_19

I see you respond to many people's steam problems, and you seem to know so much. The rad has the vent about 1/3 up on the opposite side of the inlet valve. There is, of course, a tap on the upper most part of the rad which has its screw in place, so that is not the problem. Is there a "better vent" I could use...or another trick I could try?

Jeff_17

Steam rad problem

I have a one-pipe steam system...pressuretrol set at .5 and 1.5...everything working WELL..no bangs...no wet steam...I have read Dan's LOST ART book and has helped my system immensely! I have one radiator that seems to be giving a problem. Second floor, It heats all the way across, but only the top 1/4 to 1/3 gets hot! The bottom stays ice cold..so consequently, the room stays a little cold. I have tried different vents, but nothing. I even tried operating rad without a vent....still the same. Air comes out..so that is not a problem. It is a tube rad..like hot water style....not steam column type.... I have two others like that, but they are fine. The others in the house are the original 1903's! Any ideas....or solutions.

Mike T., Swampeast MO

Wild guess

Have you verified that the shut-off valve is fully open and actually works when you turn the handle?

Jeff_19

It does!

I actually checked that to see if anything was blocking the flow of steam. Works perfectly well....and no broken parts. Still cannot figure what is wrong...I pictured the steam rising to the top, condensing and helping to slowly heat the bottom...but nope.

Unknown

Steam vents and water vents

On a hot water system, the vents are put high in a radiator because air is lighter than water.

Steam is lighter than air, so if your vent is high on the radiator, it shuts while the radiator below the vent still has air in it. Steam then stops expanding into the air bubble.

The vent rate might be too low for that room, and the radiator heats up later in the cycle than the others.

The boiler may not be able to make enough steam to completely fill every radiator. It will always be the same place in the system that gets shorted.

Or something else...

Noel

Unknown

Sure

Since you already know the timing of the different radiators heating up from cold, you can check a couple things.

First, if the piping is uninsulated down under, we don't have much hope of balancing. Also, the vent on the end of the main downstairs needs to get hot and close within about a minute from the time the header above the boiler gets hot.

These things ensure that all radiators can begin to heat together, and the radiator vents aren't the only things venting the mains.

NOW, turn off the system for a bit to cool the piping, and pull that radiator vent out. Run the system till a puff of steam gets out of the (missing) vent hole in the radiator, and shut it off. See if the conditions change in the radiator with an open hole. If it improves, a different vent will help out. If it stays the same, the problem is elsewhere.

OK so far?

Noel

Jeff_17

I have tried...

operating the rad without a vent. Seems to heat about the same, but never ran the system til steam popped out!
My mains are vented. I have two...a longer one and a shorter one. The longer carries Three Gorton Mains on the very end of the dry return just as it dips to the wet return..and the shorter carries TWO Gortons. All rads get hot at the same time...exactly the same...and I have timed the mains to check how much venting there I would need. No problem there. What would happen if I moved the pressuretrol cut-out to about 2.5. Will that help or hurt!?

Unknown

won't help

you won't build pressure and shut off with a vent out and no steam at the hole. That would be close to 0 PSI on the gauge, so it isn't a pressure problem. Is your boiler going on and off and on and off during the time no steam is coming out of the hole?

If you want some clear answers, you need to do some homework. How many square feet EDR of radiators is on this system? What is the firing rate of the boiler? Does the boiler area piping meet the manufacturers instructions?

If you post a JPG picture of your boiler and the piping above, that would help.

Noel