Near boiler venting and other questions

dev_hollows

Hello everyone, thanks in advance for your advice. Forgive me if I get my terminology wrong and please correct me!

I own an "1890" three-family house (a.k.a. it was built before the city kept records so they know its at least as old as 1890 but who really knows.) The boiler was apparently originally coal-fired, later converted to oil, and currently gas fired (converted in 1980 & still going strong). However, the piping doesn't match the description here. The boiler is fairly centrally located, though a little farther back than center & a littler closer to one side than the other. As you can see in the picture below, there are two boiler risers to the header. After another riser, the main heads to the centerline of the house where it splits left and right. (Left goes out of a tee, then the main continues back before hitting a 90' to head right.) There is no Hartford loop.



From there, the mains run to the front & back of the house along the centerline, with takeoffs to either side through a tee set at 45 degrees from the main, up a few inches before hitting a 45 degree joint & heading out sloping up to the outside edge of the house where they hit a 90 for their journey upward. The first floor radiators each have their own run from the mains & a short riser to head through the floor. A second run from the main (in the vicinity of the one for the first floor radiator) goes up to the second floor where it tees off to the second floor radiator before heading to the third floor and terminating at the third floor radiators.

Near the end of the main at the front of the house another tee from the main drops down roughly 45 degrees to a short nipple, then a 45, then slopes down towards to the outside edge of the house and turns back towards the boiler. It eventually reaches the boiler lower than the main but higher than the header. It hits a 90 (with a vent) and heads down to the bottom of the boiler where another 90 brings it into the boiler. There are three similar returns - each with a vent at the 90 that brings it down to the bottom of the boiler. You can see one in the foreground in the picture above & the other two in the background. Below, the two in the foreground.



- I haven't measured the mains either for diameter or length, nor have I measured the radiators yet. (Though I intend do within the next day or so.) I did just have to replace one of the radiator valves though, & it was inch & a quarter (1-1/4").
- The mains are almost entirely insulated in the basement (yay asbestos! ... NOT!)
- The radiator vents are a hodgepodge... probably mostly no-name & HD type that have been muddled with over the years.
- As you'd expect, there is one thermostat in the room with the second-closest-to-boiler radiator. That room, of course, has no problem maintaining the set point.
- The rest of the house- not so pretty. Some radiators get piping hot all the way across, others get lukewarm all the way across, & some get hot on the inlet side & stay cold on the vent side, a few don't seem to get hot at all. Yesterday I was on the third floor while the boiler was firing & remove the vent entirely on one radiator that was cold. A brief sound of air movement through the vent hole (I'm assuming it was pressure release but don't know for sure), & in a short time that radiator was finally getting hot. When I shook the vent, it rattled, & when I blew into the inlet I sprayed a little water onto my face from the orifice, but then I could blow into it & it seemed to "vent" no problem. On that radiator, as far as I know, no steam ever exited the vent hole -- I believe first floor thermostat was satisfied before it ever got that far. At the opposite (front) end of the house, I had another radiator that was getting a little warm on the inlet side, & I removed the vent within a few minutes of removing the first vent. No sudden pressure relief here, & blowing into the inlet of the vent it seemed to release pressure just fine.

Issues:

Main venting -- it seems as though my only main vents are located at the end of the dry return before they drop down into what would be considered the wet return. Is a valid description? If so, is that a valid configuration? Even if it is a valid configuration, it seems likely that the three vents are way too small. Plus, I'm highly suspect that they're probably not working -- they look pretty cruddy, and I'm sure they haven't been checked in at least 7 years (since I've owned the place), probably much longer. The house is ~35 feet wide and ~65 long... looking at floor plans I'd estimate the front main to be 35' long plus 45' of dry return before the vent and the rear main to be 15 feet long plus its return(s)? Like I said I'll measure tomorrow and find out for sure, but in any case, three tiny-looking little vents (maybe one of you can identify them for me?) for all that main is (I'm guessing) totally inadequate. I'm sure you'll need actual measurements to tell me for sure, but do you think I am on the right track that these vents are inadequate?

The radiator venting clearly needs to be addressed. Some are probably stuck closed, others are sure to be sized wrong. Anyway from what I've read you want to vent the mains well, & then size the radiator vent based on the radiator size. My current "plan" is to buy maid-o-mist 0220-5L vents & start them all out with the mid-sized orifices for my average radiators, slightly smaller for smaller radiators, larger for larger radiators, and see how it goes. (I prefer to have a fixed orifice size so that tenants don't adjust them & screw up the balance, and change them out as needed if a room is legitimately not getting enough heat or is getting too much heat.)

I'm wondering if the fact that it's a three-story building comes into play here -- given two equally sized radiators on the 2nd and 3rd floor that share a riser, do I need to vent the 3rd floor one slightly faster than the 2nd floor one to make up for the extra riser length? Or, should I add vents at the end of the riser to take care of the whole riser and vent the radiators equally? I'm tempted to put one size smaller-than normal orifice in the thermostat room's radiator, but I'm guessing you'll actually tell me that if my mains are vented properly and the other radiators are vented per their individual sizes, all that will do is slightly overheat the other rooms by delaying the thermostat room's radiator from filling up with steam?

Some boiler questions:
- Is my header properly configured? I'm a little confused about bullheaded tees and their role here...
- Is the lack of a Hartford loop concerning?
- The two red knobs on the front of the boiler match the knobs above and below the sight glass, which leads me to believe they are also valves... any idea what their purpose is? Any chance they're some sort of skimming port? They're pretty small diameter, not like the skim ports I've seen videos of people cleaning out... but there don't seem to be any other skim ports
- What can you all tell me about the sight glass/low water shutoff/pressuretrol assembly I've got? Anything special I need to know about it?
- The only pressure gauge I see is if I recall correctly a 0-30 which seems to be stuck at .5 or so. I'm guessing I should replace this with a new, lower-range gauge?

Snowmelt

Man that's old with all them questions you might want someone to stop by and explain it all to you, you can also buy book or two from this websight. At I ask where are you from?

BobC

You have a lot of work ahead of you, you should buy The Lost Art of Steam Heat and read it. That book has all the information you will need to get that system working correctly, it's well written and easy to understand.

Make sure the boiler does not get over 2 PSI, less would be better. You may have to add a low pressure gauge (0-3 PSI) because the standard 0-30 they use on boilers are not accurate at the low end of the scale.

Your main venting has to be addressed, you need about twice as much venting on the long main as the short main. I would start out with 2 Gorton #2's on the long main and one #2 on the short main. The Gorton #2's are a large vent, make sure you have room for them, they also should be 6" above the mains or dry returns. use a level and make sure the mains all have slope so water can find it's way back to the boiler.

Next make a list of all radiators; list the size (H,W.D # of columns deep, # of columns across), how much horizontal pipe feeding it in the basement, and how much vertical feet to reach the radiator. The volume of air in those pipes and of the radiator itself will determine the vent rate you want. Check all horizontal pipe to make sure it is pitched back towards the mains and check the radiator to make sure they are pitched back towards the inlet pipe.

You can do all of this yourself or you can pay someone to do it for you.

Bob

nicholas bonham-carter

First get your main venting up to scratch, checking the speed of steam to end of main in the basement against the open pipe vent. Leave the radiator vents alone for now, unless there is clearly one which is not working. Later on you can do some fine tuning with the orifice vents, but the mains are the most important to begin with. Put a low-pressure gauge on with the vaporstat. If you see the pressure rise above 1.5 psi to often, you may need a vaporstat.
The red knobs are probably an early way of determining the water level in the boiler ( steam from the upper, and water from the lower, when opened ) is there a working LWCO?
Don't worry about the boiler suppy piping for now. While it is not ideal by today's standards, the larger steam chest of an older boiler can compensate to some degree.
Just encapsulate your asbestos insulation for now. Later you can have it removed, and replace it with 1inch fiberglass.--NBC

dev_hollows

Snowmelt said:

where are you from?

Central Massachusetts.

BobC said:

You have a lot of work ahead of you, you should buy The Lost Art of Steam Heat and read it. That book has all the information you will need to get that system working correctly, it's well written and easy to understand.

It's in my amazon shopping cart as I type.

BobC said:

Your main venting has to be addressed, you need about twice as much venting on the long main as the short main. I would start out with 2 Gorton #2's on the long main and one #2 on the short main. The Gorton #2's are a large vent, make sure you have room for them, they also should be 6" above the mains or dry returns. use a level and make sure the mains all have slope so water can find it's way back to the boiler.

Understood. My biggest question is whether the vents being at the end of the dry return is okay or if I should move them to the actual end of the main (front and back of the house)? The only vents I can find that would vent the main are the three right at the boiler on the returns.

BobC said:

Next make a list of all radiators; list the size (H,W.D # of columns deep, # of columns across), how much horizontal pipe feeding it in the basement, and how much vertical feet to reach the radiator. The volume of air in those pipes and of the radiator itself will determine the vent rate you want.

Okay makes sense. This confirms my suspicion that the third floor radiators will generally need slightly more venting because they have extra vertical pipe volume to deal with as compared to the second floor and first floor, in combination, of course, with the actual radiator size. Thanks!

I assume the book will have calculations for me to determine proper venting?

BobC said:

Check all horizontal pipe to make sure it is pitched back towards the mains and check the radiator to make sure they are pitched back towards the inlet pipe.

I'll be bringing my level with me when I go this evening to take measurements.

nicholas bonham-carter said:

First get your main venting up to scratch, checking the speed of steam to end of main in the basement against the open pipe vent.

How do I measure this? I understand about performing all my tests with similar startup conditions (run the boiler till it produces steam, shut it off for 30 minutes prior to each test so I'm comparing apples to apples.) But I don't have an answer yet about the validity of the venting being at the end of the dry returns near the boiler -- since my only vents are at the ends of the dry returns near the boiler, how do I time steam to the end of the mains at the front and rear of the house? Do I just change my test to wait for steam at those vent points at the ends of the returns? And just to be clear, I remove the vent, leaving an open hole, start the boiler, and watch for steam to exit the hole? Then reinstall the vent and... what? I haven't found clear instructions for how to tell whether the vent is even working, or when steam reaches it...

nicholas bonham-carter said:

Leave the radiator vents alone for now, unless there is clearly one which is not working.

Forgive my ignorance, but how do I tell if there is one that is clearly not working? Would the ones I removed in the tests I described above count as clearly not working, since the radiators got hot after removing the vents? Or -- might they be working but due to inadequate main venting the radiators just aren't getting steam... I suppose I have to wait until after I fix the main venting before I can tell one way or the other??

nicholas bonham-carter said:

Put a low-pressure gauge on with the vaporstat. If you see the pressure rise above 1.5 psi to often, you may need a vaporstat.

I'm not sure what you mean here. I have a vaporstat, but don't see a way to add a gauge to it. Do mean replace the 0-30 gauge on the top of the boiler with a low pressure gauge so I can see if the vaporstat is working?

nicholas bonham-carter said:

The red knobs are probably an early way of determining the water level in the boiler ( steam from the upper, and water from the lower, when opened )

Ah, good point. Ok I guess that makes sense. Anybody else seen these anywhere and can confirm?

nicholas bonham-carter said:

is there a working LWCO?

Yes, it's pictured in the attached images (IMG_2053)... the low water cutoff, vaporstat, and sight glass are all in a connected to a shared apparatus hanging off the side of the boiler.

Anything special I need to do with it, other than opening up the drain valve once in a while to test and make sure it shuts off on low water?

nicholas bonham-carter said:

Don't worry about the boiler suppy piping for now. While it is not ideal by today's standards, the larger steam chest of an older boiler can compensate to some degree.

Thanks, just to make sure I understand -- because there's extra room in the boiler for steam inside the boiler itself it's less critical that the header slows down the steam and lets the water drain out? Similar to how a half-full tea kettle only whistles when it boils but a kettle that's topped off will spit and sputter when it boils?

nicholas bonham-carter said:

Just encapsulate your asbestos insulation for now. Later you can have it removed, and replace it with 1inch fiberglass.--NBC

Will do. In the meantime obviously taking extra care not to disturb it.

nicholas bonham-carter

Just keep the main venting in the same location, with antlers to offset the vents, and to allow for the installation of more than one Gorton #2 on each dry return. When they are all together, it is easier to check on their operation.
Put the low pressure gauge on a manifold with the vaporstat/pressuretrol.--NBC

dev_hollows

nicholas bonham-carter said:

Just keep the main venting in the same location, with antlers to offset the vents, and to allow for the installation of more than one Gorton #2 on each dry return. When they are all together, it is easier to check on their operation.
Put the low pressure gauge on a manifold with the vaporstat/pressuretrol.--NBC

Gotcha. Ok thanks. So again... how do I actually check them and time the venting time? I'm assuming I *should* be able to hear air venting and venting and venting and then suddenly stop? Or... is it a gradual slow down?

BobC

The vents begin to close as the temperature of the vent increases. They do not make much noise at low pressures so you may not hear the vent working depending on the other noises in the basement. You can tape a piece of tissue to a stick and hold it up to the vent to see when air stops coming out of it, be careful about using your fingers because they will release some steam before they close and that will burn you if your not careful.

In your case with the vents at the end of the return, your vents will work longer but you only care about the time it takes the end of the main to get steam hot.

The best way to test is to time the time it takes for steam to travel from the boiler output pipe (since you don't have a real header) to the end of the main. I have only one 12 ft main and it takes about 2-1/2minutes for the stem to get from my header to the end of that main. The boiler had been off for an hour when I did the test, I use a digital kitchen timer to track the time.

Bob

dev_hollows

BobC said:

The vents begin to close as the temperature of the vent increases. They do not make much noise at low pressures so you may not hear the vent working depending on the other noises in the basement. You can tape a piece of tissue to a stick and hold it up to the vent to see when air stops coming out of it, be careful about using your fingers because they will release some steam before they close and that will burn you if your not careful.

Awesome, thanks.

BobC said:

In your case with the vents at the end of the return, your vents will work longer but you only care about the time it takes the end of the main to get steam hot.

The best way to test is to time the time it takes for steam to travel from the boiler output pipe (since you don't have a real header) to the end of the main.

I apologize for my ineptitude here, but I'm still confused about how to tell this -- since I can't look into the pipe and tell that steam has reached the end of the main, how do I tell steam has reached it? Just exterior temperature of the end of the main using an infrared thermometer?

Fred

dev_hollows said:

BobC said:

The vents begin to close as the temperature of the vent increases. They do not make much noise at low pressures so you may not hear the vent working depending on the other noises in the basement. You can tape a piece of tissue to a stick and hold it up to the vent to see when air stops coming out of it, be careful about using your fingers because they will release some steam before they close and that will burn you if your not careful.

Awesome, thanks.

BobC said:

In your case with the vents at the end of the return, your vents will work longer but you only care about the time it takes the end of the main to get steam hot.

The best way to test is to time the time it takes for steam to travel from the boiler output pipe (since you don't have a real header) to the end of the main.

I apologize for my ineptitude here, but I'm still confused about how to tell this -- since I can't look into the pipe and tell that steam has reached the end of the main, how do I tell steam has reached it? Just exterior temperature of the end of the main using an infrared thermometer?

The easiest answer is when you can't hold your hand on the pipe, either the end of the Main or the antler the vents are mounted to, you got steam there.

dev_hollows

Fred said:

The easiest answer is when you can't hold your hand on the pipe, either the end of the Main or the antler the vents are mounted to, you got steam there.

Perfect.

SWEI

dev_hollows said:

Snowmelt said:

where are you from?

Central Massachusetts

https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating

dev_hollows

SWEI said:

https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating

Thanks! I'm surprised I hadn't noticed the "find a contractor" link in the nav bar. Oh, wait, it's not in the nav bar when you're in "the wall". Interesting. Anyway, thanks! Good to know there are companies in MA that know what they're talking about Though, I should've been more specific -- the house is in Worcester MA, which is "central" in terms of population but not necessarily geography. Funny how we get used to our local terminology and lose sight of how most people will interpret certain phrases. Springfield is nearly an hour from Worcester.

Anyway, I spent a bunch of time at the house the other evening. Took two of the three main vents off -- totally plugged, not a chance in heck they are working. With them off I'd get a nice puff of steam every few seconds. Took a few better pictures of the vents to remind myself what I'll need to do to make room for the Gorton #2's.




So, I'll start by double checking my main venting requirements (double checking my main lengths to make sure I get enough venting) and getting the appropriate venting installed and see where we go from there.

dev_hollows

By the way just for kicks I took some notes about the existing equipment: The two vents that are pictured together are Dole No. 1933 Vents, and the third vent is a Gorton #D.

The boiler itself is marked as an American Radiator Company No. 2 Ideal Redflash boiler (from my searching that dates it between 1920 and 1929 or so, can any one confirm?)



The manufacturer tag is a little hard to read in the picture but it's marked as Number 2S7. Series 8B. Maybe that'll help narrow down its age?



I forgot to take a picture of it but the gas gun's installer tag dates it at January of 1980! Happy 35th Birthday! (Everyone who sees it from the home inspector to the gas company tells me, "Oh, they don't make that gun anymore and you can't get parts. If it dies you're up a creek!")

Here's the existing gauge... clearly gotta go. I've seen mention of data loggers in other threads but no details -- anyone have recommendations for a gauge that I might be able to digitally collect data from? Or, do you just get a regular analog gauge and a separate digital sensor for data logging?

KC_Jones

If you are actually going to throw out that gauge I will take it off your hands, pay for shipping it to me whatever. I love that old stuff!

Jamie Hall

On the main vents. If all the main vents -- working or not -- were or are at the end of the dry returns at the boiler, I'd bet there are crossover traps at the ends of the steam mains going into the dry returns.

Make sure those are working. Then you do NOT need to put main vents on the steam mains. What you do need to do is put adequate main venting at the boiler. It is quite possible that putting main vents on the steam mains without fixing the crossover traps will cause more trouble than it fixes!

And do get Charles to look at it.

vaporvac

Besides being old, what's wrong with the gauge. That old equipment is generally so much better than the new. It can still be used in conjunction with the new since you need a 0=30 gauge anyway.

dev_hollows

KC_Jones said:

If you are actually going to throw out that gauge I will take it off your hands, pay for shipping it to me whatever. I love that old stuff!

Hey @KC_Jones, I assume there is some sort of private messaging system on this forum, I'll see if I can find it and send you a message. Once I replace it, I have no use for the gauge but would hate to throw it out. (It doesn't work, for the record -- it's always been at the reading you see in the picture.)

Jamie Hall said:

On the main vents. If all the main vents -- working or not -- were or are at the end of the dry returns at the boiler, I'd bet there are crossover traps at the ends of the steam mains going into the dry returns.

@Jamie Hall‌: The connection between the mains and the returns look like mirror images of the take-offs -- the takeoffs (is that the right term?) go up 45 degrees for a few inches before sloping up slightly on their way out to the risers, and the connection to the return mirrors that -- 45 degrees down for a few inches before continuing a slightly slope all the way back to the drip line into the wet returns. All three vents are at the top of the drip lines. There's nothing fancy in the connection between the mains and the returns -- just regular pipe fittings, so unless I just don't understand what a crossover trap is, I'm pretty confident in saying I don't have any. I'll take a few pictures next time I'm there.

Jamie Hall said:

Make sure those are working. Then you do NOT need to put main vents on the steam mains. What you do need to do is put adequate main venting at the boiler. It is quite possible that putting main vents on the steam mains without fixing the crossover traps will cause more trouble than it fixes!

Just to make sure I understand this comment -- a crossover trap would take the place of a vent at the end of the main, correct?

But, if I don't have crossover traps then I treat the vent locations that I currently have as the main vents and size venting appropriate for the mains?

dev_hollows

vaporvac said:

Besides being old, what's wrong with the gauge. That old equipment is generally so much better than the new. It can still be used in conjunction with the new since you need a 0=30 gauge anyway.

@vaporvac‌ the needle has been in the same position as the photo since I bought the place in 2008. If you have any suggestions for fixing it I'd love to keep the 85+ year old gauge...

dev_hollows

vaporvac said:

...you need a 0=30 gauge anyway.

Actually, just thinking about this post again -- why do I need one? I thought the goal was to tune your system so that it operates at a minimum pressure, no more than a couple psi. What do I need the large range gauge for?

KC_Jones

Most places require it by code....working or not it needs to be there. If it were mine I would just leave it alone and add the low pressure gauge.

Fred

Virtually all local building codes in the US require a 0 _ 30 PSI gauge on the boiller, plus anything else that you want.

dev_hollows

KC_Jones said:

Most places require it by code....working or not it needs to be there. If it were mine I would just leave it alone and add the low pressure gauge.

lol, ok, gotta love code . so, just add a working low pressure gauge where the plug is on my existing tree. Thanks!

Edit: Thanks @Fred, too.

dev_hollows

Okay, two more questions. The long main is about 40 feet long and the short main is about 20 feet long -- so it seems that three Gorton #2's will be just the trick. I have them on order.

Now to the questions:

1. I have three returns and three vents. Correct me if I'm wrong but the Gorton #2's are 1/2" thread, so I'll need to reduce two of the vent taps down to 1/2" one way or another (the third one already comes off the return at 1/2"). Anyway, in order to get the vents higher than the mains, I'll need to move them from their current locations... one at least 2 feet, and the other two probably 4+ feet (haven't measured yet). Should I be worried about pressure/friction loss over that kind of distance? I.e. should I run out at 3/4" and then reduce to half right before the vent? Or, is it okay to reduce to 1/2" right off the bat and run 1/2" the rest of the way out to the vent? Other than making sure there is pitch back towards the return, is there anything else I should be concerned about with a several foot run for the vents?

2. Regarding those three returns... two of them are from the long main, and one of those two comes all the way from the end of the main and the other comes from between 1/2 and 1/3 of the way down the main. Should I be concerned about the shorter loop venting sooner than the longer loop? Or, does it not really matter since they'll probably be within a couple minutes of each other so the radiators will still all get steam at about the same time (assuming the radiators are vented properly).

Thanks!

Fred

Not clear why the vents have to be moved from their current location. Are they actually on the Mains or the returns? If they are on the returns, they don't have to be above the Mains, they just need to be above the returns.
I would not run a 4ft pipe for the vents. That just adds more resistance to deal with and there is no reason to do that.
I am not sure what you mean by one of the returns comes from 1/2 to 1/3 of the way down the Main or why one Main has 2 returns. Is it a main with a branch off of it that dead ends?
Are these actually true, full size returns or just Drip legs to catch and drain water from low sections of the Mains?
From the pictures I see above, it looks like the vents should go right where they are now as those look like true returns.
Help me understand what you are trying to do by moving them.
Also, a 1/2 inch pipe can accommodate 2 Gorton #2's so you are fine reducing right at that outlet, unless you think you might need to add a 3rd Vent at some point. Then you need to make all the antler pipe 3/4" and just reduce it at the vent.

dev_hollows

Thanks Fred. I guess I misread this:

BobC said:

The Gorton #2's are a large vent, make sure you have room for them, they also should be 6" above the mains or dry returns.

... and was thinking they had to be above the mains, but I guess in my case it's just 6" up from the dry returns right? In that case I probably don't have to move them far, but will likely have to rejigger a bit depending on how big the #2s really are.

I was also reading another thread about the Gortons not liking to reopen in high ambient temperature and was wondering if the radiation from my 1920s American Radiator Company No. 2 Ideal Redflash boiler, which radiates quite a bit of heat, might cause any issues. Any idea?

They're real, full size returns unless I just don't know the difference. The two mains start high (near the boiler) and slope down towards the end of their runs, where the returns dump right off the end of each main and head back to the boiler. About a third of the way down the long main one of the branches actually goes through a huge masonry structure that supports an enormous fireplace but when it comes out (sloping up and away rom the main) it hits a tee -- one side goes up to a riser and the other side goes to the third return back to the boiler.

Each of the returns comes back to the boiler above the top of the boiler and drops straight down nearly to the floor before hitting a 90 and heading back into the boiler. The two vents you see pictured close to each other are on separate returns that don't join until below the water line. So, with 3 vents I'm at 1 Gorton #2 per 20 feet of main, unless you add in the length of the returns, too, in which case I could double up the vents on each one and be good to go.

Does that clear up the third return and how there are two returns off one main? I'm not really sure why they didn't just let that branch drip back into the main and keep running down to the end like the rest of them, and ideas?

Steamhead

On the long steam main, you want your vents all the way at the end. That way the entire main has the entire venting capacity available to it. The intermediate return from the tee near the fireplace structure just drains condensate- it does not need a vent.

Fred

Do what Steamhead says. Put 2 Gortons on your longest return on an antler and the other one on the second return. Don't worry about that return from the fireplace area.
I doubt that the ambient temp. You kind of have to play that by ear but right now, that is the only logical location to get some venting on your system and the returning condensate should help them open. I doubt your boiler room gets that hot??

dabrakeman

What does a crossover trap at the end of the main look like and how do you test to make sure it is working? Like Dev my main vents are at the final termination of my two dry returns.

Fred

Take a look at picture #3 in this thread. It shows a Crossover trap: http://forum.heatinghelp.com/discussion/152733/some-questions-about-another-steam-system-with-pictures#latest

dabrakeman

I assume then that this is not a crossover trap? 2 pics:

Fred

Nope, but that certainly looks like where your vents should go for that Main.