Non-functioning Broomell Vapor system

mmanske

Hi all -

We recently came in possession of a large ~1920 Colonial in NJ and trying to wrap my head around the steam system. (I'll preface this by saying I have no history in steam/HVAC/etc, so any ideas I'm working with here are half-**** regurgitations of "Lost Art of Steam" readings and YouTube sessions)

The biggest issue is that the system (which was working when we did our inspection last month, of course) has taken a **** and won't push any heat. Boiler fires, pressure climbs up and up, but the steam doesn't get beyond the basement pipes and none of the radiators heat up. Admittedly though, I chicken out when we get to beyond about 5 PSI and hit the kill switch.

The first thing that jumps out to me is that there's not a single vent in any of the basement piping. I would expect some main venting downstairs, especially given the size of the system (360,000 BTU boiler, 21 radiators) but there's nothing. The radiators themselves are a Frankenstein show, but the majority seem to be the Broomell Vapor system (which I believe is designed to work at low pressure?)

I can understand that the system is might be poorly balanced, but I can't put together what might have changed in the last few weeks to go from working to no heat anywhere.

System details:

• 2-pipe steam
• Peerless EC-06 Oil
• Condensate unit w/ jet pump
• Radiator EDR Spreadsheet: https://docs.google.com/spreadsheets/d/1UvbM2vC0pZK8DibbJHdLg9TqKdrWq5cReFdZHUDhT1c/edit#gid=0
• 3D CAD of Basement Pipeing: https://app.sketchup.com/viewer/3dw?WarehouseModelId=538f3e91-7715-4948-94c3-0a605d030f70
  • red = steam sends
  • blue = condensate returns
  • yellow = water/accessory piping

Any thoughts on where to start to get this system back online would be very much appreciated

Thanks

Jamie Hall

Unhappily your diagram won't open for me.

Like most vapour systems, there were no main vents on the steam mains. Also, like many earlier vapour systems there were no crossover traps. So don't expect to find them. Rather, the entire system was originally vented to the atmosphere, and the combination of low steam pressure and carefully calibrated valves meant that little if any steam even made it into the dry returns, never mind into the atmosphere.

Very elegant. No moving parts.

A modernized system will have a main vent or vents on the dry return(s) before they drop to the wet return and the boiler, but if the condenser was left in place it may be after the condenser and somewhat less than obvious.

The fact that the steam pressure rises -- at all, never mind to 5 psi! -- and that the change happened abruptly suggests to me that somewhere there is a valve that got closed. I know it sounds stupid, but it happens.

Try running the boiler up to perhaps 1 psi -- no more -- and trace out where the steam gets to.

The system, when you get it running properly, should operate on no more than 7 ounces pressure -- you'll need a vapourstat.

clammy

Are you sure the radiator valves are open ,some times people do the strangest things for odd reason I would be looking at that it wouldn’t be the first time . Does the pressure gauge return to zero when everything is cooled meaning maybe the gauge is bad . You stated you turned it off as the pressures raised how long was it running for and Was the near boiler piping hot to the touch . You may not be giving the system enough time to start heating . I would recommend picking up a copy of the lost art so you can educate yourself and it will give you a idea weather or not you have the right contractor instead of wasting your time . Not all plumbers hvac guys know steam most will always attempt cause we all gotta eat and work right and some will just say that’s the way Steam is and you should replace . The broomwell system you have was one of the Cadillac of 2 pipe system in its day and when not butched up w either the graduated supply valves or water seal traps removed and a improperly piped boiler worked amazingly well . The biggest promblem is usually bad near boiler piping huge differences in original boilers water line compared to the new boiler water line and usuallya huge cast of knuckle heading and lets no forget a big one in my book the lack of pipe insulation being it gets abated and never re insulated properly which usually leads to poor system performance but awesome basement heat . Hopefully yours issues are minor but some one gonna have to do a look see Peace and good luck clammy

dopey27177

Beautiful drawing of the system.

Can not run at 5 PSI.
The definition of a vapor system is the steam is at vapor pressure.
Broomell operates at depending on the steam main size) minimum 4 oz. to 10 oz steam pressure.
The Broomell system you have has been modified,
The jet pump I assume is used to make vacuum. When the pump operates it pulls the steam around the system and allows depending on the dept of the vacuum steam temperatures as low as 160 degrees.
Broomell is older than condensate pumps in home heating system. The condensate pump vent is where the air leaves the system.
With the vent open to the atmosphere you will never make vacuum.
Cheap test!

Install a check valve on the vent from the condensate pump. The check is to be installed backwards, letting system air out and closing if the system goes into vacuum. The check valve should have soft seat
so it can seal tight when the system is in vacuum.

Pictures of the equipment near the boiler would be more helpful than the cad drawing.

I apologize for the quality of the scan but it should help you understand the the system make over.

Buy Dan's Book The Lost Art of Steam Heating as this one book that helped me make old systems work for many years.

Need some pictures of mechanical equipment and the piping to the boiler and system.

To make your system work on vapor and vacuum there will be some trial error.

Jake

mmanske

@Jamie Hall

I appreciate the insight. It seems wild that the vapor system needs no main vents. Would that function the same even without the receiver/relief apparatus? http://gluedideas.com/content-collection/Radfords-cyclopedia-of-construction-Vol-9-Heating-Systems-Plumbing/images/Radfords-cyclopedia-of-construction-Vol-9-Heating-Systems-Plumbing_Picture98.jpg

Seems like the existing Pressuretrol is too coarse to fine-tune at the low pressures this needs to work from. I'll recheck all the valves and see if I can trace out anything useful from the heat.

Is there anything I would need to adjust on the Broomell union elbows at the bottom of the radiators? Can't find a lot of information, but it seems like there's no moving parts on them.

Sorry the CAD wouldn't load, but here's a screenshot of the relevant pieces if it's helpful:

mmanske

@clammy

Good point on the pressure gauge. It does go to zero after the system has cooled though and I let it run about 10/15 mins before I hit the kill switch. At that point, the pipes are definitely getting hot, but the heat never travels all the way up to the radiators - seems to die out 3/4 of the way over to the risers. The Pressuretrol certainly isn't working (or pigtail needs to be cleaned), but the gauge at least seems to be functional.

With the Broomwell system, what happens one it gets butchered up? Maybe 75% of the radiators have the original quintuple valve & the union elbow, but the rest have had some modern air valves & thermostatic traps added over the years. Would those changes be enough to throw the whole system out of whack, or is it possible for them to co-exists?

mmanske

@dopey27177

Appreciate the PDF link. I've been reading through the "Lost Art of Steam Heating Revisited" all week. It's got me excited to get to know my setup, even in spite of it's current state.

I initially thought the same thing about the jet pump creating a vacuum to pull the steam, but it's piped between the condensate unit & the equalizer so I'm fairly certain it's just being used to pump water between the two (I could very well be wrong on that though).

Took some pictures of the near-boiler setup - the lighting's terrible, but hopefully it's enough to paint a picture:

EBEBRATT-Ed

@mmanske

Try "find a contractor" on this site. @clammy or @EzzyT may respond. Sounds like that system needs a good going over

clammy

On original broomwell systems and most vapor system in homes they never had condensate pumps originally ,so it was installed later most likely as a band aide . Is the vent for the condensate tank open ? If plugged there’s a issue air will never leave the system and there will be no pressure differential so slow or no steam distribution the fix is usually increase the pressuretroll settings not the right answer . As for the supply valves and traps not all being original there usually changed as part of a knuckle heading process that never realized that the boiler was running to hi a pressure and blowing steam through the water seal traps and pressurizing the dry returns and then the original supply valves would start to leak steam so usually the cure was to replace the valve ,usually the replacement valve are not graduated so adjusting the inlet can be a issue . From the drawing jake posted it looks like multi dry returns tying together above the water before dropping into the master trap before dumping into that Hoffmann condensate pump . Usually there would be some original air elimination and possibly a return trap w a equilizer line to push condensate back into the boiler all that stuff has long been removed . Where are you located in jersey peace and good luck clammy

Jamie Hall

A few minor comments.

First. if you reached 5 psi in 15 minutes, something somewhere is blocking steam from even getting into most of the mains, never mind the radiators.

Second, the Broomell elbows have no moving parts and -- normally -- need no maintenance. It is possible, however, if there is a lot of crud, for the air release hole to get blocked. Rare, but it happens. That specific radiator then will heat poorly, if at all.

The switch to thermostatic radiator traps will have had no effect on the overall operation of the system -- but does indicate that someone sometime messed with it who didn't understand it. Not exactly news...

If you look carefully at how the Broomell was originally intended to operate, you will find that it didn't need an artificial or valved vent at all. Rather, the dry returns all went to the condenser -- just a big radiator -- and then any condensate from that went back to the wet returns, while the condenser itself was open to the atmosphere -- usually through the chimney.

Broomell systems were not intended to operate under a vacuum. It is extraordinarily important to understand that they -- like all vapour systems -- were and are intended to operate under a very low pressure differential between the steam mains and the dry returns. Typically less than 7 ounces. The gauge pressure of the steam main doesn't matter, nor does the gauge pressure (or vacuum) of the return. All that matters is the difference between them. Failing to realise that it is the pressure difference which matters, not the gauge pressures, is perhaps the most common problem people have when trying to understand how they operate -- or why they don't.

At some point someone decided to put a condensate receiver on it, who knows why, and -- since condensate receivers usually are fed with an F&T an F&T trap. Again, someone who didn't know how the system was supposed to operate (and, possibly, as a result of problems with one of the newer thermostatic traps) and found steam in the dry return from too high a system pressure. In other words, a kludge to "fix" a problem without doing anything about the problem itself. The condensate receiver, by itself, won't necessarily cause a problem -- although it is quite likely unneeded (if the extra water volume is needed, it should be an equalized tank at the boiler water line); the F&T may give problems.

An F&T trap is a miserable main vent -- though often used as one. You will probably, however, need to put a main vent or main vent cluster on the system where all the dry returns combine before they drop to the F&T trap.

But before you go much farther, find out why -- at 5 psi after only 15 minutes or so of steaming -- the steam isn't screaming through those Broomell equipped radiators. Something's stopping it.

dopey27177

I noted the yellow lines and they are listed as water and acc. piping.


Are these lines connected to the heating system?
Maybe they were air removal lines when the system was changed to induced vacuum and not connected to the jet pump.

The watts model regulator may not be an F&t trap there fore air is not vented from the return system.
If you need an F&Trap get one that has a .312 orifice for venting air, that is the largest orifice availible for an F&T trap.

You need to install a a Honeywell L408J1033 vaporstat 0-4 psi for better control of the steam pressure.
First setting is 6"HG on to 1 psig off. This to be used till you can refine the operating prressure. Can be lowered to 4 on 8 off.

Next if the original return els are in place you can clean them especially the hole that lets the air out.

Make sure the steam valves are open and operating.
If the valves are broken and need to be replaced orificed valves are available Mepco manufactures them and since you have the edr schedule you can ask them to set each valve at the factory.

Pressure gauges for the boiler Weksler 31/2" face 30hg/0/30 psi gauge will let you know if you are pulling vacuum.

I did not see the vent pipe from the top of the condensate tank so maybe that is why system air is not leaving the via the condensate receiver.

Maybe here is another problem maybe the jet pump is piped in wrong and are is being discharged to the atmosphere.

Try this for a first test.
Install a vent on the top most outlet of condensate receiver install a cheap check valve with a soft seat to allow air out and stop air from going in, (check valve installed backwards)

You have time with summer approaching to diddle with the system.

Start with the cheap stuff first, but get the combination pressure vacuum gauge and vaporstat s that will be a permanent part of the boiler trim.

JAKE

dopey27177

I am amazed that I got wrapped up into this discussion as a mavin that can fix things.
Lets get back to basics.
This Broomel System as shown most probably was a simple 2 pipe vapor system without bells and whistles.
As we all know the boilers were coal fired. We also know that these coal fired systems had a receiver/regulator that put water back into the boiler and a float with a chain connected to a damper that banked the coal fire.
Additionally a condensing radiator installed at the ceiling condensed any steam may have entered the return lines, the outlet of the condensing radiator was piped to a chimney or vented to the atmosphere.

The system when off, not making steam would go into vacuum because the steam in the system and boiler would cool and create a vacuum that would allow steam to form below 212 degrees.

Some engineer figured out a way to turn this system into an induced vacuum system cheaply. Because it was done without the use of a manufactured condensate/vacuum tank and pump set, without the appropriate controls and vents this system can not operate efficiently or at all.

The only way to make it run correctly is to restore it to a two pipe steam system fix what needs to be fixed and then if you want a vacuum system install the appropriate equipment.

Jake

Jamie Hall

Just for the sake of curiopsity, @dopey27177 , can you kindly explain the physics of how a system which is open to the atmosphere through the outlet of the condensing radiator connected to the chimney can "go into a vacuum"? Not sure I can quite see how what amounts to a pipe open to the atmosphere at one end can have a pressure appreciably less than atmospheric (a vacuum) at the other...

dopey27177

Not shown in the lost art of Steam Heating a check valve on the air release system that lets air out and prevents air in, that way the system can make some vacuum as the the condenses and boiler water cools below steaming.

Jake

Jamie Hall

Interesting. Never seen one with a check valve that would crack at 2 ounces (which is what was wanted)... I suppose they did have them.

Some Hoffman Equipped systems did have vents which would hold against a vacuum, but those are a little weird in that they will only do that under some rather odd conditions which should never happen if the system is running properly.

dopey27177

Cracking pressure for check valves not an issue, Dunham's penny valves are 3/4" and have a very light thin copper penny under 1/8 of an ounce lifts with less than a breaths pressure, the penny valve sis on top of the B tank condensate/vacuum pump and evacuates air from some real big buildings, the port is 3/4".

Had to go back to the files.

No check or air check, the seal is at the to of the accumulator, built in. not shown. Additionally as stated in Broomell's patent the vapors that go to the chimney, when the chimney is heated causes a partial drop in pressure in the system and helps draw the steam around the system, (partial vacuum).

At 80 years old I do forget some things and then have to do research all over again.
pardon me for running my pen before the brain is fully engaged.

Jake

Steamhead

EBEBRATT-Ed said:

@mmanske

Try "find a contractor" on this site. @clammy or @EzzyT may respond. Sounds like that system needs a good going over

@mmanske , it's time to bite the bullet and hire a Steam Man. These are two of the best.