cold rads

gfe

I have a steam 2 pipe with vents on rads system...some of the rads stay cold even though the inlet valve body is hot to touch...I have opened and closed the valves several times and the stem does move up and down (not sure what may be going on inside the valve). the condensate valves are open. I took off the vents and blew thru them and they are fine. I even left the vents off the rads so they would heat faster..(I will put them back on if steam would come out). I realize the inlet valves may be "frozen", but the stems move up and down when you open and close them. I don't think there are "traps" on these rads in this type system. The valves look like simple inlet and outlet ones. Thoughts?

Robert O'Connor_7

gfe..

If the air can't get out, the steam can't get in. Start by checking the main vents...Robert O'Connor/NJ

kevin coppinger_4

if you have....

a 2 pipe system you usu. have traps on the returns to the rads NOT vents. Sounds like you need new traps....BUT there again I am no steam guru...kpc

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

gfe

no these are vents (like hoffman # 2) midway up on the rads above the condensate valve...

gfe

the main vents are working fine. and in some rooms one rad will be working fine and the others will have the problem I have described above...doesn't make sense does it?

clammy

insulation

Are your steam mains insulated and is there main vents in the basement on your dry returnd or do all your returns drip into a wet return in the basement ?What is your pressurtrol set at, may be it's time to call a pro ?

jeff_51

cold rads

Just a suggestion, but if it is the same rads that never get hot even when you take off the vents, then I would pull the bonnets off the valves and see if the discs are broken off the stems, but only do this when the system is off!!!!

gfe

Mains are not insulated. Recently had asbestos removed. wet returns in basement. pressuretrol set at 2 psi.
If I take bonnet off valve (when system off), will the valve seat be seized to opening? if seat comes off when bonnet is removed with steam then I assume nothing wrong with valve? thanks for input

Steamhead

This is a 2-pipe air-vent system

You need to insulate your steam pipes. Steam is condensing inside them instead of moving to the radiators. Use fiberglass pipe insulation with a wall thickness of 1 inch.

Pay special attention to venting the mains. Measure the length and diameter of each main and tell us what vent is on it. We can tell you if they're sized properly.

Run the system at very low pressure. If you have a Pressuretrol turn it all the way down. A Vaporstat will work better since it cannot be set higher than 1 PSI.

Do NOT vent the return lines on this system. You don't want to let steam into them- this will cause banging.

The Hoffman #2 vents are vacuum vents. These really only work well with coal firing. If the burner shuts off before the system is completely filled with steam, the air can expand as the system cools and block the flow of steam on the next cycle. I'd change them to standard vents.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

gfe

mains not insulated. recently had asbestos removed. pressuretrol is 2 psi. mains in basement are hot. A couple of branches off mains in basement are cold and of course these radiators fed by the branches are cold. but the valves are open (unless disc has sealed valve). remember, I have taken temporarily taken off the vents so that is not the problem. I guess I need to take the valve knob off to see if the disc has sealed the inlet. But the way the square (not hexagonal) nut that the stem goes into cannot be accessed by a wrench...it is positioned in such a way that I can't get a wrench on it. Thoughts? thanks

gfe

Steamhead, your reputation precedes you! I have some of the insulation but have not started it yet. will get on it soon. But I don't understand why the steam won't go to the rad when the rad is only about 10' above the hot "branch" in the basement and the vent on the rad is off? It seems that steam should be moving right thru that rad...but nothing..not even the body of the inlet valve is warm?

Steamhead

If the steam is condensing in the mains

it won't reach the radiators- even with the vents off. Sounds bizarre, but it's true.

Let us know what happens when the pipes are insulated. I'll bet you see a BIG difference.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

gfe

thanks...may be a while before I can insulate, but I will let you know....thanks again!

gfe

cold rads

steamhead, I turned the pressuretrol down from 2 to 1 and turned the "wheel" inside from 3 to 1. now the house is cold...all rads cold and the thermostat is on 70...thoughts?

Steamhead

Air venting problem?

If the air can't get out, the steam can't get in. Have you measured your mains yet?

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

gfe

Yes, there are 2 mains...each with a hoffman # 75 at each end that "sputter". one main is 63' tthe other is 90'. the boiler is a weil mcclean (400,000 btu output). 38 rads in the house. thanks a lot....

Steamhead

You need

three Gorton #2 vents on the long main and two on the short one. This will make a huge difference. If you can't locate Gortons in your area, go to www.gorton-valves.com. Get in touch with Ken Kunz and tell him I sent you. He will see that you get them.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"