2 pipe poor heat in upstairs rad

Steamhead

DaveSmith2 said:

...............Can’t I just make the hole on top the vent larger? 

No. If you do the vent won't close. Get the Gorton, then compare it to that micro-vent. You'll be glad you did.

mattmia2

As long as the main is pitched properly (toward the drip in to the return at the floor), the condensate from the one pipe radiator should run to that drip and in to the return, shouldn't be an issue if there is only one. Numerous rads piped as one pipe may be too much condensate for that main sized for 2 pipe.

The screw either fell out of the handle on the 1 pipe rad or the cover wouldn't fit over the handle.

Steamhead said:

My first impression is that vent on the dry return is much too small. You need a large vent there- I'd use a Gorton #2. Is that the only steam main/dry return pairing in the system?

Or the vent is closing before the problem part vents because a lot of the radiators look to have a normal steam valve on them instead of the richardson vapor valve and the boiler has a pressuretrol on it so steam is probably just blowing right through some of the radiators.

When the system is heating and the problem rads are not, feel the vent, is it very hot like steam temps? this is to see if it is closed by steam that is in the return that doesn't belong there.

DaveSmith2

Steamhead said:

...............Can’t I just make the hole on top the vent larger? 

No. If you do the vent won't close. Get the Gorton, then compare it to that micro-vent. You'll be glad you did.

I put the old vent back on it. Idk if you saw the pic on the previous page. It’s a Gorton #1, the hole is much bigger than the one in that tube shaped vent. My neighbor gave my that one. 

DaveSmith2

mattmia2 said:

As long as the main is pitched properly (toward the drip in to the return at the floor), the condensate from the one pipe radiator should run to that drip and in to the return, shouldn't be an issue if there is only one. Numerous rads piped as one pipe may be too much condensate for that main sized for 2 pipe. The screw either fell out of the handle on the 1 pipe rad or the cover wouldn't fit over the handle.

My first impression is that vent on the dry return is much too small. You need a large vent there- I'd use a Gorton #2. Is that the only steam main/dry return pairing in the system?

Or the vent is closing before the problem part vents because a lot of the radiators look to have a normal steam valve on them instead of the richardson vapor valve and the boiler has a pressuretrol on it so steam is probably just blowing right through some of the radiators. When the system is heating and the problem rads are not, feel the vent, is it very hot like steam temps? this is to see if it is closed by steam that is in the return that doesn't belong there.

I’ll check the vent tomorrow when the heat is on. I check the pitch of those mains and they’re level more or less. Very very slight pitch towards the furnace. The section after the one pipe radiator riser is like perfectly level, but not pitched towards the wall where they come down and meet that check valve. 

clammy

After seeing your system pics I can only comment on a few right off the bat issues I see . Your boiler is not piped correctly no header no equilizer , the is zero insulation on your mains that helps nothing . Without out correct piping your not making dry steam without dry steam usually 2 Nd floor rads never see to much steam . Your boiler should have a vapor stat to keep your pressure extremely low especially since you have those Richardson water seal type traps at any thing above about 4 to 6 oz steam will pass into the dry return and end all steam distribution . A lack of insulation is not helping anything especially those 2 Nd floor rads . Has your boiler been washed out flushed of all mud some times thats all that brings a system back to working as it did if it had worked any better in the past . Some times terrible mud build up in the boiler drastically effects the boilers ability to produce any decent steam leading to system issues . Flush it out ,through repeat filling and draining until the water is clear . Best advise is find a pro to re pipe the near boiler piping and install a vaporstat and wand and clean the boiler , then reassess the performance .
Peace and good luck clammy
Happy New Year

DaveSmith2

clammy said:

After seeing your system pics I can only comment on a few right off the bat issues I see . Your boiler is not piped correctly no header no equilizer , the is zero insulation on your mains that helps nothing . Without out correct piping your not making dry steam without dry steam usually 2 Nd floor rads never see to much steam . Your boiler should have a vapor stat to keep your pressure extremely low especially since you have those Richardson water seal type traps at any thing above about 4 to 6 oz steam will pass into the dry return and end all steam distribution . A lack of insulation is not helping anything especially those 2 Nd floor rads . Has your boiler been washed out flushed of all mud some times thats all that brings a system back to working as it did if it had worked any better in the past . Some times terrible mud build up in the boiler drastically effects the boilers ability to produce any decent steam leading to system issues . Flush it out ,through repeat filling and draining until the water is clear . Best advise is find a pro to re pipe the near boiler piping and install a vaporstat and wand and clean the boiler , then reassess the performance . Peace and good luck clammy Happy New Year

Yes I know the insulation is missing on the supply run in that back cellar. Years ago the I believe the return pipe that goes through that crawl space was replaced as it was leaking and the plumber must have taken the insulation off when he was working on it. I plan on replacing it. 

I understand what you’re saying but I’m not looking to be spending thousands $$ to rip pipes out and change furnace parts. It’s cheaper to just run a ceramic heater in the room if it came to that. Plus 2 of the 4 radiators upstairs work fine. 

My neighbor and I drained the boiler a few weeks ago when we replaced that small line on the bottom next to the check valve. Every week since forever when the furnace is in service I drain the water out the valve on the bottom till it runs clean and refill. Thanks for the reply and happy new year to you as well. 

reggi

As long as your not getting heat from those 2 radiators anyway why don't you disconnect the valves and traps and move them out a bit and tip to see if there's anything mucked up.... now the spuds look like they are centered on the drain side .. look at my earlier pictures for water seal , because of that dip tube they had to be centered so the tube wouldn't jamb on the bottom of the radiator when it was being wrenched in...now if you stick a thin stiff wire in the the spud you'll feel it get some resistance as it hits the bend of the tube.. and you'll probably have to spin the wire for it to make the bend... now at least you know if they were all there to begin with. Just as the tube bends ( look at photo ) there's a air hole on top that helps with the water level and seal unit...try making sure that's not blocked by finding something thin enough to penetrate the hole clearing anything that might be obstructing it...
Then I'd pour some water through the inlet and tip it into a pan to clear any debris...
If you have a Shop vac now would be a good time to use it..put the hose right on the spud and vacuum away..

Then ...on to the the inlet valve!..
Without the radiator you should see if it's opening and closing as as it should be..and if you have anything missing from the valve that might of slipped off and is blocking the pipes inlet...(It happens) IF you're not sure get a couple wrenches and pull that valve off so you can better inspect......

That will get you started... I'll be back to finish but don't wait for me to get started...You might want to get some 3/4" 1/2" pipe caps .. just in case it gets cold

DaveSmith2

reggi said:

As long as your not getting heat from those 2 radiators anyway why don't you disconnect the valves and traps and move them out a bit and tip to see if there's anything mucked up.... now the spuds look like they are centered on the drain side .. look at my earlier pictures for water seal , because of that dip tube they had to be centered so the tube wouldn't jamb on the bottom of the radiator when it was being wrenched in...now if you stick a thin stiff wire in the the spud you'll feel it get some resistance as it hits the bend of the tube.. and you'll probably have to spin the wire for it to make the bend... now at least you know if they were all there to begin with. Just as the tube bends ( look at photo ) there's a air hole on top that helps with the water level and seal unit...try making sure that's not blocked by finding something thin enough to penetrate the hole clearing anything that might be obstructing it...
Then I'd pour some water through the inlet and tip it into a pan to clear any debris...
If you have a Shop vac now would be a good time to use it..put the hose right on the spud and vacuum away..

Then ...on to the the inlet valve!..
Without the radiator you should see if it's opening and closing as as it should be..and if you have anything missing from the valve that might of slipped off and is blocking the pipes inlet...(It happens) IF you're not sure get a couple wrenches and pull that valve off so you can better inspect......

That will get you started... I'll be back to finish but don't wait for me to get started...You might want to get some 3/4" 1/2" pipe caps .. just in case it gets cold

So I had the problem one in this bedroom pulled out because I swapped the ball trap from the one in the next room over to this one because this one was missing the ball. The inlet valve is fine. I did even stick a piece of a coat hanger in where the outlet is where the trap connects and I didn’t get any muck out. 

It’s not bound up inside the radiator because when the heat first starts to come up, I can hear the ball rolling back and forth in the trap. Assuming this shouldn’t happen because no other radiator in the house with these ball traps does this. I think this is the problem. Why is the ball rolling back and forth? Air pressure has to be working on it from both sides. Seems to be illustrating air from the supply pushing in vs air from the return pushing in fighting each other. It also hammers when this happens. Mind you this happens when the heat is first coming on and the actual steam isn’t making it up there yet and the radiator is completely cold. 

I was thinking about putting another vent on the return main in that back cellar. There are plugs in the top of the pipe. Problem is they’ve been in there for probably half a century if not longer lol. I only have a MAP gas torch here. Probably need to get the surrounding metal red hot to get them out and the MAP won’t do it. Need acetylene torches for that. I guess I can try soaking it with penetrating oil. 

Steamhead

I still say you need the Gorton #2. It will vent something like four times as fast as the #1.

reggi

I'm going grocery shopping but did you get a wire or dental tool in the radiator outlet and feel around to top of the bend ( from the inside) til you poked through the air hole?  That would mess you up if the water climbed that high because there was no air to release it .. like a straw put in glass and pinching the end and lifting it out...it hold the water until it gets released and gets air..then it flows

DaveSmith2

Steamhead said:

I still say you need the Gorton #2. It will vent something like four times as fast as the #1.

I can source one of them. They’re available online 

DaveSmith2

reggi said:

I'm going grocery shopping but did you get a wire or dental tool in the radiator outlet and feel around to top of the bend ( from the inside) til you poked through the air hole?  That would mess you up if the water climbed that high because there was no air to release it .. like a straw put in glass and pinching the end and lifting it out...it hold the water until it gets released and gets air..then it flows

Man I really don’t want to pull this radiator back out lol but I will. All the connections are broken loose now and I put copper anti seize on them so they’ll come back apart no problem. But there was no water in it when I was messing with it. 

mattmia2

What temp is the vent on the return. If the system is working properly it should never see steam so it should never close.

DaveSmith2

mattmia2 said:

What temp is the vent on the return. If the system is working properly it should never see steam so it should never close.

Right now it’s difficult because it’s pretty warm outside so the heat isn’t really working hard. But I know without a doubt I’ve been in that basement before and heard that vent hissing in the back cellar

DaveSmith2

reggi said:

I'm going grocery shopping but did you get a wire or dental tool in the radiator outlet and feel around to top of the bend ( from the inside) til you poked through the air hole?  That would mess you up if the water climbed that high because there was no air to release it .. like a straw put in glass and pinching the end and lifting it out...it hold the water until it gets released and gets air..then it flows

Ok so I pulled the radiator back out and checked that hole and it seems it’s open. There was no water in the radiator either. 

reggi

Well it shouldn't be empty ..is this the one that had the gutless trap with the drift that steamed when you pulled the drift out ?
The ball works ( from the copied page)

"Water Seal Ball Check Union Elbow
The "Richardson” Water Seal Ball Check Union Elbow is made 
in only one size 1/2 inch, which is ample for all radiators. It is 
placed at bottom of radiator and operates as follows: when supply 
valve is opened, the ball check opens and allows the condensation 
to pass freely into the return. If the supply valve is closed tight, 
the ball check closes to prevent water or vapor backing into the 
radiator. This return valve is entirely automatic. The air vent 
opening in the tailpiece of the elbow equalizes the pressure on 
both sides of water seal, preventing syphoning. It also allows 
the air in radiator to escape into return as soon as supply valve is 
opened. "

Well it was worth a shot.. I'll sit out the venting as I don't have any so I couldn't say and I'll defer to those familiar... I'll help if I can..G/l

mattmia2

the radiator with the modern steam trap with no guts, it doesn't heat and it still doesn't heat with the cap off the trap, and there isn't air coming out from the radiator side, is that correct?

DaveSmith2

reggi said:

Well it shouldn't be empty ..is this the one that had the gutless trap with the drift that steamed when you pulled the drift out ?
The ball works ( from the copied page)

"Water Seal Ball Check Union Elbow
The "Richardson” Water Seal Ball Check Union Elbow is made 
in only one size 1/2 inch, which is ample for all radiators. It is 
placed at bottom of radiator and operates as follows: when supply 
valve is opened, the ball check opens and allows the condensation 
to pass freely into the return. If the supply valve is closed tight, 
the ball check closes to prevent water or vapor backing into the 
radiator. This return valve is entirely automatic. The air vent 
opening in the tailpiece of the elbow equalizes the pressure on 
both sides of water seal, preventing syphoning. It also allows 
the air in radiator to escape into return as soon as supply valve is 
opened. "

Well it was worth a shot.. I'll sit out the venting as I don't have any so I couldn't say and I'll defer to those familiar... I'll help if I can..G/l

So by that description of how it works is the trap is irrelevant when the supply valve is open? So it only works if you shut the radiator off and keeps water and vapor from backing up through the return? 

DaveSmith2

mattmia2 said:

the radiator with the modern steam trap with no guts, it doesn't heat and it still doesn't heat with the cap off the trap, and there isn't air coming out from the radiator side, is that correct?

No, it will work when the steam actually makes it up to the second floor. If I unscrew the vent on the side of it I can feel air pushing out when the heat starts coming on and steam when it does make it up to it. Again if I went and cranked the thermostat up to 70, I would get heat up here. The problem is on that back run off those mains that feed the one piper and these two problem ones. The radiator in the next room over from the one piper works fine, but it’s piping doesn’t run off those mains. 

I feel like it almost has to be something with that one piper. It’s the only other thing on that run. I know that check valve on the floor where those mains meet is working because it’s hot on the supply side of it and cool on the return side so it must be doing it’s job. I suppose I could close the supply valve on the one piper and see if that makes any difference. 

DaveSmith2

Idk if this is of any consequence but these are the two radiator valves on the system. The one on the left is from the radiator upstairs with the gutted trap. The one on the right is from the one pipe radiator downstairs. The one on the right seems to have a bigger outlet.

reggi

@DaveSmith2
Your sure that Radiator Inlet valve has dropped it's Jenkins and isn't blocking the steams path ( especially the one that has strapping holding the stem open) 

As far as the dip tube air hole... remember Dan's reminder.."if Air can't get out Steam can't get in"

On that note:

The air vent 

opening in the tailpiece of the elbow equalizes the pressure on 

both sides of water seal, preventing syphoning. It also allows 

the air in radiator to escape

reggi

The radiator in the next room over from the one piper works fine, but it’s piping doesn’t run off those mains. 

As long as we're piecing this together.. I took another look at your boiler and see the one Main or Header ? Let's see the runs as the "Other Main" would have to have a end and return so if you start where the main spits to 2 there might be something that helpful in figuring out your unique system 

DaveSmith2

reggi said:

@DaveSmith2
Your sure that Radiator Inlet valve has dropped it's Jenkins and isn't blocking the steams path ( especially the one that has strapping holding the stem open) 

As far as the dip tube air hole... remember Dan's reminder.."if Air can't get out Steam can't get in"

On that note:

The air vent 

opening in the tailpiece of the elbow equalizes the pressure on 

both sides of water seal, preventing syphoning. It also allows 

the air in radiator to escape

No I just inspected the guts of that valve yesterday when I had the radiator disconnected. I opened and closed it and watched the sealing piece inside move up and down. I have that cord wrapped around it because it leaks a little steam when it does get steam. 

DaveSmith2

reggi said:

The radiator in the next room over from the one piper works fine, but it’s piping doesn’t run off those mains. 

As long as we're piecing this together.. I took another look at your boiler and see the one Main or Header ? Let's see the runs as the "Other Main" would have to have a end and return so if you start where the main spits to 2 there might be something that helpful in figuring out your unique system 

There is no other run like in that back cellar. All the other radiators in the house branch off the main big supply pipe above the furnace in different directions. I can snap some pics tomorrow but I doubt you’ll see anything interesting 

DaveSmith2

Reggi, I checked out the pipes you wanted to see but it’s just not possible to get a pic which shows the whole layout of those other pipes as they go off in different directions and I can’t get an angle to take a pic that will show any detail as I’d have to stand back so far. 

Anyway I think I made some progress though. I put some insulation on that supply run in the back cellar. I just wrapped some R134 around it I had lying around for now. I was thinking about what one of you guys was saying that it’s probably another radiator in the system causing the issue. So I shut off the radiator downstairs in the living room that has the ball trap with the ball missing.
I got some consistent heat up here last night. There is still some pressure feeding back up from the return to this problem one because I still hear that damn ball being pushed back and forth. 

What if I put a vent on this one?

reggi

Thát radiator waterseal (ballchecheck) return is piped to the thermostatic trapped/vented radiator in the next room that both share a single supply riser and return riser .,and the last time I saw it the Webster didn't have any innards so it stand to reason That Radiator would be getting pressure as well as the waterseal ballchecheck radiator but the vent might be releasing the that causing the ball to prematurely open... Fix the Webster and remove the vent..

DaveSmith2

reggi said:

Thát radiator waterseal (ballchecheck) return is piped to the thermostatic trapped/vented radiator in the next room that both share a single supply riser and return riser .,and the last time I saw it the Webster didn't have any innards so it stand to reason That Radiator would be getting pressure as well as the waterseal ballchecheck radiator but the vent might be releasing the that causing the ball to prematurely open... Fix the Webster and remove the vent..

I think they make a repair kit to replace the guts of that trap. Honestly though I really don’t care about that radiator working right now because the room is unused and the door stays closed. I shut it off earlier. I want to see if it makes any difference in this room. Since there’s no trap and it has a vent I’m figuring if any part of this is pressure in the return, it can escape from the vent if need be. 

Whatever I did yesterday definitely made a difference because I’m getting some decent heat up here now. I’m leaning more towards the insulation did the trick as opposed to shutting the one radiator off downstairs. There’s still about a 4 foot section where the supply goes into that crawl space I have to insulate too. Just really not looking forward to crawling in there lol.

bburd

Venting will not drain the condensate out of the radiator. In a one pipe system, it drains back through the steam pipes; but they are sized and pitched to work that way. On two pipe, condensate needs to go down the return, which is difficult if the smaller return pipe has steam pressure in it.

It may work better with a vent, but probably not as well as it was designed to. 

mattmia2

Your issue is steam blowing through other radiators and closing the vent before the air is out. Putting a vaporstat on the boiler to keep the pressure under 8 oz. Or so and making sure the radiators have metering valves is how you keep steam out of the return. The pressure in the return is the same pressure in the supply. The trickle of condensate on the bottom of the pipe will happily flow past that.

reggi

@DaveSmith2 Well if a radiator inlet or outlet isn't functioning correctly and shutting them off in various sections of the house that have little to no functional value to you at this time, ( Though you must always be careful of cutting of the heat to any room or section of your house as you don't want things freezing up and bursting) brings heat to the other rooms and helps identify and narrow down the issues where they are isolated from the system until repaired, for those reasons I'd agree for testing purposes and comfort on a temporary basis to proceed at your own risk.. First check the operation of your boiler safely devices , LWCO etc..

BTW... You said you have one supply main and everything branches off that... You posted the end of the supply main and the air return main dropping into a wet return to your boiler..
Q: Are ALL the air returns piped to the same air return main that drops in the photo you posted?

DaveSmith2

reggi said:

@DaveSmith2 Well if a radiator inlet or outlet isn't functioning correctly and shutting them off in various sections of the house that have little to no functional value to you at this time, ( Though you must always be careful of cutting of the heat to any room or section of your house as you don't want things freezing up and bursting) brings heat to the other rooms and helps identify and narrow down the issues where they are isolated from the system until repaired, for those reasons I'd agree for testing purposes and comfort on a temporary basis to proceed at your own risk.. First check the operation of your boiler safely devices , LWCO etc..

BTW... You said you have one supply main and everything branches off that... You posted the end of the supply main and the air return main dropping into a wet return to your boiler..
Q: Are ALL the air returns piped to the same air return main that drops in the photo you posted?

That room doesn’t have any piping through it or anywhere even close to it that could freeze. I’ll check but I’m pretty sure yes, they are all piped to the same return. 

DaveSmith2

mattmia2 said:

Your issue is steam blowing through other radiators and closing the vent before the air is out. Putting a vaporstat on the boiler to keep the pressure under 8 oz. Or so and making sure the radiators have metering valves is how you keep steam out of the return. The pressure in the return is the same pressure in the supply. The trickle of condensate on the bottom of the pipe will happily flow past that.

What vent are you referring to? The 4
radiators downstairs are the one piper, so it can’t be that one blowing steam in the return. Next room over which has a ball in the trap and I inspected it and moves freely. Next one over missing the ball(the one I just recently shut off). Last one is in the kitchen and that one has a thermostatic trap which appears to be working as I checked the inlet/outlet temps and seem
correct. So the only one I would suspect causing a problem would be the one missing the ball. 

I’m getting some pretty consistent heat up here now so something I did worked. I’m leaning toward insulating that supply. Years ago a plumber replaced the pipe in that back basement crawl space due to it leaking. He must have removed the insulation and never replaced it. 

I get what you’re saying about adding a pressuretrol and those fancy thermostats on all the radiators but aside from not wanting to spend a ton of money, I’m afraid if I go monkeying around with this setup I’ll open a can of worms and cause more problems for
myself than I have now lol. 

mattmia2

I dint' say anything about thermostatic valves on the radiators. The radiators should have vapor style valves on them, the radiators you have with the lever handles have that type of valve. There were a few vapor valve styles that had a knob type handle so it is possible some of those radiators have the proper valve on them too.

The controlled opening on the valve combined with keeping the pressure from the boiler very low with a vaporstat instead of a pressuretrol limits the amount of steam that comes in to the radiator to the amount that the radiator can condense. That is how this system is designed to work. Where you are missing the vapor valves you can use an orifice plate, a metal disk that is connected in the union of the radiator valve that has a hole of a specific size in it that limits the amount of steam that can get in to the radiator.

The amount of a gas that flows through an orifice is a function of the pressure and the size of the hole so if you don't control the pressure then you don't control the amount of steam going in to the radiator. The first step might be to put a tee under your current pressuretrol and add a 0-3psi gauge there so you can see what pressure the system is operating at. If it never builds pressure then you could get away without buying the somewhat expensive vaporstat to control the pressure.

In your system the steam entering the radiators pushes the air out in to the returns and the vent out of that vent on the return near the back wall. If steam passes through a radiator and in to the returns then it will heat and close the vent and venting of any radiators that still have air in them will stop and those radiators will not heat.

That ball trap is a secondary defense against steam getting in to the returns. It can stop a little steam but if far more steam is going in to the radiator than can be condensed by the radiator then it is going to evaporate that water and get in to the return. It doesn't seal off like a modern bellows steam trap.

You cold try opening the valves on the radiators that heat first only a little bit and try to match the amount of steam supplied to the amount it can condense but I think that will be very difficult unless you are controlling the pressure.

bburd

mattmia2 said:

Your issue is steam blowing through other radiators and closing the vent before the air is out. Putting a vaporstat on the boiler to keep the pressure under 8 oz. Or so and making sure the radiators have metering valves is how you keep steam out of the return. The pressure in the return is the same pressure in the supply. The trickle of condensate on the bottom of the pipe will happily flow past that.

Based on your previous posts I have found you quite knowledgeable, Matt; but I see that you disagreed with my post about this. If you are correct in what you say above, why do two pipe air vent systems need loop seals / drips to wet returns? And why was the steam trap invented? I’m not trying to start an argument, just curious.

mattmia2

bburd said:

mattmia2 said:

Your issue is steam blowing through other radiators and closing the vent before the air is out. Putting a vaporstat on the boiler to keep the pressure under 8 oz. Or so and making sure the radiators have metering valves is how you keep steam out of the return. The pressure in the return is the same pressure in the supply. The trickle of condensate on the bottom of the pipe will happily flow past that.

Based on your previous posts I have found you quite knowledgeable, Matt; but I see that you disagreed with my post about this. If you are correct in what you say above, why do two pipe air vent systems need loop seals / drips to wet returns? And why was the steam trap invented? I’m not trying to start an argument, just curious.

The condensate doesn't fill the pipe, it is just a trickle on the bottom of the pipe. Pressure won't stop it from flowing unless there is a sag in the pipe causing it to fill the cross section of the pipe.

mattmia2

The balls in the traps rattling are probably the result of steam hitting water and collapsing so you are getting quick pressure changes.

reggi

Now on a side note I can honestly say that I've never heard my balls clink, clank, or rattle .. The balls aren't magnetic nor brass.. they feel pretty hefty for their size... .. Being you're missing some balls perhaps the ones you have aren't even the original ones.. just some that fit.. weight and size matters..
Post some pictures and I'll pull one out to compare  ⚫

mattmia2

bburd said:

If you are correct in what you say above, why do two pipe air vent systems need loop seals / drips to wet returns? And why was the steam trap invented? I’m not trying to start an argument, just curious.

Both are to keep the steam out of the return. The steam trap closes positively when the heat of the steam hits it so steam does not pass in to the return. In the 2 pipe air vent the water seal with the return dropping in to the wet return keeps the steam from one radiator out of the return of another radiator so that steam through the return doesn't close the vent before the air is out of the radiator. Some 2 pipe air vent systems don't have the returns individually dropping in to a wet return and sometimes they have problems with radiators not venting because of the steam in the returns.

DaveSmith2

reggi said:

Now on a side note I can honestly say that I've never heard my balls clink, clank, or rattle .. The balls aren't magnetic nor brass.. they feel pretty hefty for their size... .. Being you're missing some balls perhaps the ones you have aren't even the original ones.. just some that fit.. weight and size matters..
Post some pictures and I'll pull one out to compare  ⚫

It’s only this one radiator that does it, no other one does. I don’t have one on hand to take a pic of. I’d have to pull one out of a working radiator. There probably around maybe a half inch in diameter if I had to ball park it. 

DaveSmith2

I’m getting some real respectable heat up here now. To the point I even have to open the room door to let some out. But holy crap does this radiator hammer like a sob lol. It could be a little more consistent but it’s 100% better than it was. I bet it’s the insulation. I still didn’t do the section in the crawl space but I bet if I do that and maybe even through some on the section of the supply that goes up through the downstairs closet it will work even better.