2 Pipe, Vented System, No heat on first floor

gockleyd

I have a 2 pipe vented system that has developed a problem where it heats the third floor radiators great, the second floor radiators get a little heat, and the first floor radiators are cold.
This started recently and the only two things that have happened to the system are, increased use (we had been bringing the system up to temp in the morning and then letting it cool off during the day when no one was home and then bringing it back up to temp in the evening, now we are running it all day) and the boiler was over filled to the point of water coming out the 2nd floor radiator vent.

Historically(past 20 years) the system has run ok with some problems with uneven heating of the radiators(I need to adjust the vents and haven't had time) but has been pretty good.

Not sure what happened that now I am getting no heat in most of the radiators

-David

Jamie Hall

Bring the water level down where it belongs and tap the vents on the misbehaving radiators. With any kind of luck they are just stuck from wild overpressure, but they may be toast.

EBEBRATT-Ed

Looks like a two pipe air vent system to me with submerged return lines to keep the steam out.

Your probably running the pressure in the boiler too high causing the return water in the system to back up into the returns blocking the first floor heat and inhibiting the second floor heat. I will bet the steam pressure is way high. The higher the steam pressure the less heat you will get

Clean the pigtail under the pressure control and reset the pressure control to cut out at 1.5 psi with a 1 psi differential and keep the water level at a normal height. Check to see if the air vents on the mains are and radiators working
Try that first


Anyone notice all the left -right couplings in rhose return drops with the slash mark on them? And no unions except for the copper pipe

gockleyd

@EBEBRATT-Ed That is the first thing that has made any sense! I adjusted the Pressuretrol down last year in hopes of more efficiency but the system was running to cold and not heating the radiators consistently so I adjusted it back up a few months ago and I'm guessing I overshot and am over pressure.

mattmia2

Increasing the pressure will only make your problems worse. Turn it down as far a it will go without the linkage disconnecting and figure out the real problem.

gockleyd

What is normal pressures for a system like this? When I turned the pressure down I was haveing problems with some radiators not getting all the way warm.

mattmia2

Ideally 0. if it is building pressure it either means the boiler is producing more steam than the radiation can condense or air is getting trapped somewhere.

Since your system uses water seals, if the pressure is too high it will push steam past the water seal and in to parts that are trying to vent air or drain condensate and either stop steam from flowing or cause water hammer when the steam hits condensate.

Since your system is some sort of trapless 2 pipe, others that can identify your particular system will have to tell you how it is supposed to work. I suspect you have a lot of bad radiator vents but i'm not quite sure what i'm looking at, especially what those devices are at the bottom of the water seals.(maybe they are steam traps and that is actually a dry return)

Jamie Hall

gockleyd said:

What is normal pressures for a system like this? When I turned the pressure down I was haveing problems with some radiators not getting all the way warm.

Certainly less than 1.5 psi, and probably less than 0.5 psi. I still haven't found out what type of system this is, though, so I can't get much farther than that.

mattmia2

Those radiators are beautiful whatever it is.

EBEBRATT-Ed

@Jamie Hall

Two pipe air vent is what I am thinking. Dan show it in his book. He describes it as having steam in both the supply and return pipes to the radiators.

But I have also seen it piped both ways with the radiator returns all going to dry returns and the second way with each individual radiator return dropped into a wet return which keeps steam out of the radiator returns, which is what I believe the OP has. Those were old systems before steam traps

gockleyd

As best as I can tell based on what I have read. It is a 2 pipe vented system with a wet return, those devices right beside the returns merge look like check valves based on the outside of the casting(I have never had one apart) but it is also worth noting that they are below the waterline of the boiler.

clammy

Have you removed the vents on the radiators which had water spitting out of and shaked the water out and checked to see if they are still working? I would also check to make sure that after the flooding the mains that you did not inadvertently loosen mud and rust in the system. I think a good flushing of the returns and bottom of the boiler cleaning ,gauge glass assembly and low water cut off would be in order . I would guess that from the symptoms you described the air vents are most likely shot ,there seats are filled w rust and crap from when the system flooded start there . Peace and good luck clammy also great look rads very rare I run into those

gockleyd

@clammy We actually did not have any vents that spit water I have spot checked a few (pulled them and made sure I can blow air through them) and they all seem to be in working order. I ran the system last night for 5 hours and the piping directly above the furnace got warm but nothing else. This morning I pulled a couple of the vents completely and am letting the system run to see if that helps.

I am running out of ideas if this doesn't work.

Edit: Could those check valves have all gotten clogged up?

Jamie Hall

Basic concept:: if the boiler is running and boiling water, the steam is going somewhere. Either the pressure is building, or it is going somewhere. If it isn't going where you want it to go, it's going someplace else because it has found an easier place to go -- steam is lazy.

Now if it isn't going to certain radiators, but is making it to others, it's because the air can't get out of those radiators.

Keep it simple: find out where the steam is going.

HydronicGuru

Clogged checks? cant overcome boiler pressure till shut down?

EBEBRATT-Ed

@gockleyd

Check your chimney outside the house. Do you have steam coming from the chimney?

If your not getting steam to the rads with the vents out you have got some issues.

HydronicGuru

with high pressure you have been running, the 90's might be clogged at the condensate end of the radiator. let the system pressure go back to zero. Open the 90 and check for blockage. iRun a small wire threw. If it's not blocked then repeat on the valve side. These valves had little orffice holes and could clog easily. 

mattmia2

HydronicGuru said:

with high pressure you have been running, the 90's might be clogged at the condensate end of the radiator. let the system pressure go back to zero. Open the 90 and check for blockage. iRun a small wire threw. If it's not blocked then repeat on the valve side. These valves had little orffice holes and could clog easily. 

Yeah, those supply valves are likely some sort of metering valve and the boiler being that old probably has plenty of crud in it to loosen up when you flood it.

If you still get no steam with the vent removed you could try removing a valve and see if you get steam out of the supply.

HydronicGuru

Maybe I'll have to give it another thought. Always appreciate others advise. Learn something new everyday.

clammy

If the air vents seem fine then I would first make sure the supply valves are working and not blocked w mud from being flooded it happens . It’s most likely in the supply lines being if you removed the air vents from the radiators and ran the system and the 3 rd floor rads where hot then you must have debrie in the risers or the valve assembly . If you do get them working and they start banging then those checks are blocked or the radiators outlet is clogged .,systems that run fine for decades are not immune to problems when they get flooded it’s mostly all that crap that get stirred up when flooded . Unfortunely your gonna have to do some detective work for sure . Peace and good luck clammy

Jamie Hall

A gentle word to the wise here for @HydronicGuru . I am sure that you are the real expert. However, keep in mind with steam in general and vapour systems in particular, just about the time you think you've seen it all... you will find you haven't.

feedtaleone

When I turned the pressure down I was haveing problems with some radiators not getting all the way warm. get-vidmate.com instasave.onl

Jamie Hall

feedtaleone said:

When I turned the pressure down I was haveing problems with some radiators not getting all the way warm.

Did they need to? A radiator not getting all the way warm is only a problem if the space isn't heating properly -- and then the problem isn't pressure, it's system balance and venting.

Also, is your thermostat set up properly?

mattmia2

It is also possible that the weight of the water in the steam piping caused something to shift and now you have condensate getting trapped somewhere.

archibald tuttle

I can't really tell from the picture of the radiator supply valves what type of orifice steam control they might provide although some with more experience might actually recognize those valves. But if the parts of this thread that indicate you have removed the vents completely and are getting no steam are correct then I would try to disassemble the valve to see if they are mucked up, before actually trying to remove the valve altogether.

I haven't had such problems with overfilled systems and relatively standard valves but if these indeed operate around a tight but adjustable orifice, maybe that is where the blockage is. given that you are having the problem on the 1st and 2nd floors and that is where the overfill went and that you don't seem to find that the vents themselves are blocked, my best guess. And you can try one unit that isn't working and see and that would give you the work plan for the rest . . .

brian

clammy

Have you checked your main vents or any cross over traps if you have any , your main vents could be toast ? Have you checked your supply valves on the floors and radiators that are being effected . At this point I would remove a supply valve and fire the boiler if you boiler isn’t pushing steam then you have some sort of blockage in the supply piping most likely from flooding the system usually caused by heaps of rust . It may be time if you haven’t already to drain the boiler down and remove any plugs flush it ,flush any returns and assembly , re fill boiler and make sure any drain flow freely and are not clogged . It may be time that you try and get a professional in and see what They have to say ,most certainly a flair camera would be able to find where blockages are possibly . Peace and good luck clammy