CONVECTOR VENTING

crash2009

Can I get some advice on venting this convector.  Correct me if I am wrong but this is what I think it is called.  The (first picture) is the branch off the main which goes up to the second floor bathroom (about 15 feet) I suspect this branch also feeds a small room 2-D (second picture) (beside the bathroom third picture) (enclosure removed fourth picture) Recently I installed a pair of Hoffman 75's and when I did a cold start of the boiler, 2-D and 2-Bath vents were hissing and spitting and a lot of steam was coming out.  This is the first time in 5 years that I ever heard a fart out of those two.  These 2 rooms have been getting some steam maybe every second or third cycle, and they are both quite cool compared to the rest of the house. 

JStar

Old vents.

What type of vents used to be on there?

crash2009

That one

is a hoffman 1A.  That is the way I found it.  I thought it should have something bigger.  I have since replaced it with a ventrite No 1 opened to the max.

JStar

Vent size.

What made you think you needed a bigger vent size?  It may be too big, and the steam will leave the radiator too fast, causing the hissing and spitting. I would put as close to the same size as was on there before. Did the radiators get fully warm before you changed the vents? What made you change them in the first place?

jpf321

maybe the original

maybe the original vents were just stuck and failed .. why did you change the vents?

what pressure are you running? what is your pressuretrol set to?

crash2009

2-D and 2-Bath

vents were stuck open and they have been replaced.  The Ptrol Honeywell P404 I think, is now set at 0.5 and the diff is 1.  Prior to this hissing problem Ptrol was at halfway between 0.5 and 2 and the diff was 1.5, I changed the vents because I thought they were stuck open.

crash2009

I have

made a few changes since originally posting.  I built an antler which has a Hoffman 75 and a Gorton 1 on each side.  The boiler has been drained and somewhat rinsed out.  The pigtail and Ptrol have been taken apart and cleaned.  A 0-3 gauge now sits beside the Ptrol.  New pressure releif valve 15 psi.  The problem I have today is that I get no pressure reading at all on the new 0-3 

jpf321

let us know

let us know how it goes now that you have lowered your pressure ..



you may also be lacking proper main venting and now those 2 rads are being used for a larger venting need than designed for.



could it be that the other vents in the house are also all stuck open .. with them all stuck open, you probably won't hear much out of them .. but installing proper working vents that actually are now closing, that's probably why you now hear noise .. because the other ones weren't closing and therefore not hissing.

JStar

...

How did you come to the conclusion that they were stuck open? 

crash2009

I came to that conclusion,

and correct me if I am wrong, but I thought they should close and prevent the escape of steam.  I thought that the heat drove a pin into the hole to prevent the escape of steam

JStar

Yup.

Yeah, you shouldn't be having steam escape through the vents. Did you try to match the same size that were on there before?

crash2009

No

This house has been butchered over the years.  I cannot trust in whatever was there before.  The last 5 years I have been trying to do the right thing, the 25 years before me, this place was chopped up.  Radiators have been moved, replaced, sold for scrap, whatever.  2 1/2" pipes chopped out, replaced with 1 1/2", Radiator stubs here and there, The original design is mostly gone.  For a non professional like my self, its mostly trial and error troubleshooting. 

To answer your question though, there was a non-working Hoffman 1-a in 2-Bath which was always a cold room 64, and it was replaced with a Ventrite 1 set to the max, now the room is warm 67.  Same with 2-D which was ice cold, now is halfway warm 67.  The Ventrite was an improvement. The reason I started this thread was to find out if that convector enclosure vent looked like a normal way to do things to you?  I suspect that those 2 rooms are tied to the same riser and if I can somehow improve the venting, I can solve the problem of those 2 rooms being 64 degrees instead of 72 like the rest of the house. Could you have a look at the pictures at the top of the thread?  The first pic is where these 2 rooms get their steam from the main.  I thought I should be venting that pipe like a main maybe with a gorton 1 or something similar.  I also thought I should vent 2-D to the max by venting the riser and the radiator. 

JStar

Trial and error.

How is the pitch on the horizontal run-out in the first picture?



You might even want to shut off each radiator individually while the other stays open for a few boiler cycles. That could rule out any pipe sizing issue that you aren't seeing inside the walls and floors.

crash2009

The pitch

is 1/2" in 12".  Thats bad isn't it?  Should be min 1" in 12"? 

By the way, the boiler likes the lower settings of the Ptrol.  The water line in the sight glass stays higher (pumping less water) and the heat from the radiators is more intense.

JStar

Pitch.

When steam and condensate flow in opposite directions, the pitch should be 1/2" per foot, which you have. But now do you have that where you can't see the pipes?



Do you ever hear gurgling, splashing sounds in theses radiators?

crash2009

No

I have not heard any gurgling or splashing sounds.  I am about to shut off the inlet valve on one of them.  What am I supposed to be looking for after I do that?

JStar

...

Look for the hissing and spitting to stop. By doing that, I was just trying to eliminate the possibility of a pipe size or pitch issue by simulating the removal of one radiator's steam and condensate load.

crash2009

2-D and 2-Bath

These 2 rooms are the ones that have been cold in the past.  They both have had their vents changed to Ventrite #1.  After replacing the vents the hissing has stopped.  That was 2 weeks ago.  The hissing problem was solved by replacing the vents.  They were both stuck open.  Also, after replacing the vents the rooms became warmer, My estimate is about 3 degrees.  I suspect that these 2 rooms get their steam from the horizontal runout in pic 1 at the top of the post.  I am trying to get more steam up to these 2 rooms.  All I can see is the radiator in 2-D (pictured) and the enclosure in 2-Bath (pictured) 2-Bath is not a cast iron radiator, It looks like a 24" baseboard in an enclosure. and the horizontal runout in the basement (pictured) The horizontal runout is about 8' long and I estimate that it is 15' up to the second floor.  It is aimed at the 2-D/2-Bath corner of the house.

I followed your suggestion and shut off the inlet valve to 2-Bath, now 2-D heats better.  Normally the 2-D radiator heats 1.5 to 2 of its 4 sections, now its heating 2.5 to 3.  I dont know if this is important but while I was up there and the boiler was steaming I removed the vent and put the flame of my Zippo close to the vent hole...the flame was sucked in to the radiator. 

JStar

...

Sounds like a piping issue where the two radiators connect. It could be undersized for how long of a run it is.



As for the flame...was it being constantly sucked in, or did it go in and out a couple of times?

JStar

...

Sounds like a piping issue where the two radiators connect. It could be undersized for how long of a run it is.



As for the flame...was it being constantly sucked in, or did it go in and out a couple of times?

crash2009

Zippo

flame was being constantly sucked into the vent hole while the boiler was steaming.  I went up there again after the boiler stopped steaming and did the Zippo thing again.  When the boiler was off, the flame was pushed out of the vent hole in the radiator.  Is this zippo flame test normal?  Or does it give any indication of whats happening?  Is this a good thing or not?

JStar

...

Sounds like the bedroom radiator is venting too fast causing a vacuum in the pipe going to the bathroom.

JStar

...

Editing isn't working right now....





I misread your last post. If you had the bathroom off, and the flame is sucking into the open vent in the bedroom, you may be venting too fast somewhere else.

crash2009

I think we are on the same page now

2-Bath has been shut off for troubleshooting purposes.  Now back to the basement.  The next radiator down the main line is a 66 footer on the main floor by the front door named 1-FRONT.  I Zippo'd that one last night too.  I got the same flame in flame out results on that one too.

JStar

...

You said that you vented the riser going upstairs? Was it vented before? Try plugging that vent and see what happens.

crash2009

No

I didn't say that.  I said that I thought about venting the riser and the radiator in 2-D.  I don't know if that would improve anything.

JStar

...

When you do the flame test, does it ever stop sucking in after a certain amount of time while the boiler is still running? Does 1-FRONT get completely hot, or the same as the others?

crash2009

I am

going to run the flame test again, using a candle this time.  The lighter got too hot to hold and the flame wasn't so good. 

1-Front does not get hot all the way accross.  It usually heats 4 out of 11, once in a while it gets 5 or 6

I will get you an answer to your sucking in question tonight using a candle or insense

JStar

Okay.

So, this is going to sound like a lot of work, but could you make a drawing of all the radiator locations in your house, with the boiler and a general idea of piping and main vent locations. And then make a note of which ones get hot and which ones don't.



It doesn't have to be perfect. It would just be helpful to know which radiators are having problems in relation to where they are taken off the main.

crash2009

I

have allready done a 3d.  Can you open a CAD file?

JStar

Yeah.

I'd love to see it.

crash2009

Flame test

I got different results this time.  It was late and I didn't feel like waiting for the thermostat to call for heat so I turned it up to 77 F to get some steam immediately, to run the test.  I tried to use the candle beside the vent hole of the rad in 2-D, but the air kept blowing it out.  I went back to using the Zippo.  The flame beside the vent hole was doing the Tango (in-out-in-in-out) not nescesarily in that order and with MORE OUT's than IN'S.  Within a few minutes the radiator was hot all the way across and steam was exiting through the vent hole.  I put the vent back in and went down to 1-Front, the big one that never heats more than 6 sections out of 11.  By the time that it took 2-D to heat all the way, 1-Front was hot 9 sections out of 11.  I didn't even bother to flame test 1-Front because everything is doing what I expect of it.  Flame testing is over, I turned the thermostat back to 72 F,  Opened the inlet valve in 2-Bath, which had been shut off for testing, and went to sleep. 

My observations of this experiment are: 

1-when the thermostat is set at 72 it calls for heat at 71.  The boiler seems to sense that the thermostat only needs 1 degree so it only gives up just enough steam to satisfy it.  While this type of performance is good enough for the rest of the house, room 2-D only heats to 64 F.

2-when I manually set the thermostat to 76, and demand a lot of steam now, the boiler, sensing this is going to be a long cycle, gives me what I ask for.  2-D gets warm and the rest of the house gets too hot.   

JStar

Have you....

...checked the vent size on all of the first floor radiators?



Your last flame test (in and out) is normal. If it were only sucking in, and never out, you'd have a problem.



At this point, while I'm awaiting your system design drawing, I'm leaning towards either a whole system venting size issue or, if your near boiler piping is incorrect, steam in the mains condensing too fast, bogging your steam down and possibly creating a vacuum in some of the risers. And let's not forget the possibility of an undersized boiler.



Also, where is your thermostat located? I bet it's in the hottest room of the house.