Help with big old residential steam system

alexd

I just moved in to a large 1910 stone Tudor with a steam system that I'm trying to figure out before it gets into heating season. I love the way the steam heats and want to make sure I'm taking good care of the system and maximizing its efficiency. Here is what I know:

- Crown boiler installed 2001, 275,000 BTU
- Hartford loop (I sort of understand this, but not totally sure I do)
- 3 story, 5,500 sf home (2 family, but is not separately zoned)
- Automatic water feed
- Some newly replaced returns, old returns were very clogged/corroded
- most radiators get hot, but some probably need new traps
- pipes are uninsulated in basement and rest of house
- traps and vents are various types of Hoffman
The system works when fired, but yesterday I noticed the gauge glass is completely full and am not sure what's causing it to overfill. My questions are:

1. what could be causing it to overfill and how to test/repair?
2. how to prioritize trap replacements?
3. How to prioritize insulation and where to buy? Basement pipes are very large and did have asbestos which has been removed. As a result, basement gets VERY warm when hear is running. Big box doesn't carry larger pipe insulation and small stuff is very pricey.

Finally, if anyone can recommend a god steam heat contractor in Philadelphia I'm guessing that's how I'll resolve most of these questions.

Thanks!

BobC

The seal on the automatic fill might be leaking by, try shutting off the feed to the auto filler and see if that changes things. With that valve closed keep an eye on the sight glass to make sure you aren't losing water.

Does that boiler have a domestic hot water coil in it? They sometimes develop a pin hole that will fill the boiler.

You can buy 1" rigid fiberglass insulation on line, it's not cheap but it pays for itself over time with fuel savings.

Bob

Jamie Hall

Last things first -- if Ii recall correctly, Steamhead (Frank Wilson) is in Baltimore, but has been known to travel to Philadelphia now and then. He's one of the top half dozen or so in the business; if you can get him to come by, he's your man. That said, there may be others nearer by with whom I am not as familiar.

Those steam mains need insulation. There are a variety of places to buy it. Statesupply.com is one -- there are others. It's not cheap. It's worth it, both to save fuel (which it will) and to make your system run better (which it will).

Since you refer to traps, may I assume that this is a two pipe system? That is, two pipes -- the inlet with a valve and the outlet with a trap -- to every radiator? If so, and most of the traps are Hoffman, it is possible that it is -- or was -- a Hoffman equipped vapour system. If that is the case, it was designed to run on very low pressure. Therefore, checking the boiler cut-out pressure would be a good idea. It would be nice if there were a vaporstat, but I'd not bet on it. If it's a pressurestat, it should be set to cut out at no more than 1.5 psi. The vaporstat can come later.

Traps are easy to trouble shoot -- if you have an IR thermometer or can get one. If the radiator doesn't heat at all, the trap is probably failed closed. If, when the system has been running for a long time, the outlet pipe is steam hot (over 204 or so) the trap is probably failed open. Otherwise... good to go.

Proper venting is essential to proper functioning -- but without knowing how your system is piped and trapped and where the vents are, I really can't comment on that.

The over fill problem may be due to slow returns. It may be due to a variety of other factors. The first thing there to do is to turn off the automatic water feeder (not just the power to it -- close the valves), bring the water level down to about 2/3 the way up the sight glass, and run the system and see what happens to the water level. Report back on that one.

KC_Jones

@Dave0176 I know you work out of NJ, but do you travel as far as Philly? As far as the insulation goes there are a couple online sources that many of us have used. This is the one I bought from: http://buyinsulationproducts.com/ Get a good list together so you only have to order once, the shipping is bit expensive. The insulation isn't cheap no matter what, sometimes we have to spend some coin on these things. I would do 1" at a minimum. Most feel that is the best compromise between price and performance for ROI. Also you could post some pictures of your boiler and piping and we could take a look at what you have. See if there are any red flags etc. Welcome to the forum!

alexd

I'll snap some better photos when I'm home, but here is the boiler itself.

Jamie, this is a two-pipe system, neglected to mention that before. How could I determine whether it's a vapour system? All of the radiators have a Hoffman open/shut valve, a Hoffman trap, and a most also have a Hoffman float type vent, which I was confused by since it's a two pipe system.

Thanks all for the recommendations on insulation. Any thoughts on insulting pipes on first floor and up?

Finally, I'll take a closer look at water feeder and sight glass and report back. Any danger of running the boiler when it's flooded?

KC_Jones

alexd said:

All of the radiators have a Hoffman open/shut valve, a Hoffman trap, and a most also have a Hoffman float type vent, which I was confused by since it's a two pipe system.

Take some pictures of the radiators with vents, but I suspect a knucklehead got in there and added vents because they didn't know how the system is supposed to work. If you have a trap failed closed and it won't heat, you add a vent (because all steam rads are supposed to have vents?!) and suddenly the radiator heats. It's an incorrect fix for the problem and can cause other issues. You need to identify the failed traps and remove all those vents. I THINK removing the vents could help identify which traps are failed closed, but I am not very good with 2 pipe systems. Others with more experience can give more details. Insulating the pipes in the basement is about all you really need to do. The exposed pipes in the house give up their heat to the house so they can actually add a bit to your output. Running the boiler while flooded will either send excess water into the system or not work at all due to the steam not being able to escape properly. Need some amount of steam chest area in the boiler to allow the steam to escape.

nicholas bonham-carter

Turn the Hoffman vents upside down to enable you to see which radiator traps are faulty. Non-heating rads may be also the result of failed crossover traps as well.
Buying the steam books from the store here would give you a good basis of steam knowledge.--NBC

alexd

Ok, I'm attaching pics of the valves, traps and vents. The traps are mostly Hoffman no. 8, and the vents are Hoffman no. 40.

alexd

Radiators.

vaporvac

might also check the Yellow pages for commercial insulation places. I can get mine for at least 1/3 less than the prices I've seen quoted here and not shipping. The local small shops will also care some or will order and that was also cheaper due to shipping costs. I would think Philly would have plenty of these places. In any case, get some on those pipes. I read somewhere, larger pipes need thicker insulation which makes sense.
Try and post some pics of the near boiler piping and the piping leading from it. Jamie has a perfectly kept Hoffman system, so he's the resident expert in how they work.

Jamie Hall

As has been said... the vents on the radiators are someone's attempt to fix something without having a clue what they are doing. For the moment, turn them upside down -- but plan on removing them and plugging the hole where they were installed.

A vapour system is a form of two pipe steam system, designed to run on very low pressure -- no more than 12 ounces (OUNCES) per square inch. You will need a vapourstat to control that; until you get one, make sure the pressurestat is set to no more than 1.5 psi cutout. Any more can cause all kinds of problems.

Radiators which don't heat have failed traps. It's easy to fix them, but you'll need to do it.

Hoffman equipped -- and most vapour systems -- depend on crossover traps at the ends of the steam mains which connect to the dry returns. Find them, and make sure they are working. If they aren't, heat will be very slow and erratic. There should be a master vent on the dry returns, right near the boiler where they drop to the wet return. That vent must be working -- and it may well be too small. Take a picture of it, or give us the model number.

Check all your pipe pitches -- including, or perhaps especially, lines which were replaced. Also check pipe elevation -- again, especially lines which were replaced -- and make sure that the relationship to the boiler water line is correct. Dry returns must be high enough -- typically 28 inches -- to stay dry. Wet returns must be low enough to stay wet. Sounds obvious, but when we have somebody putting vents on two pipe radiators...

Jamie Hall

Come to think of it, there are three situations -- other than failed traps -- in which someone might put vents on the radiators. If the master trap was removed or failed, then vents would be needed on the radiators to restore any operation. Wrong solution to a mistake, but. Second, if the dry returns were removed or rerouted for some reason, they could no longer serve as vent lines to the master vent; again, vents might be needed, and, again, the wrong solution to a mistake. The third is that in some rather rare situations, the radiator outlets may go to a wet return, rather than a dry return. In that case a vent will be needed on the radiator, but there will be no need for a trap on the outlet.

JUGHNE

Are all your rad valves the same as the one pictured? That one looks like it could be possibly a adjustable orifice inlet valve. Someone here may recognize that Hoffman valve.

Pictures of boiler, piping at boiler and pipe vents (or anything that doesn't look like an ordinary pipe fitting) would help.

alexd

JUGHNE said:

Are all your rad valves the same as the one pictured? That one looks like it could be possibly a adjustable orifice inlet valve. Someone here may recognize that Hoffman valve.


Almost all are like this - there area few that are a more modern looking black plastic disc. I'll add some more photos tonight.

vaporvac

I have some of those on my trane vaporvacuum system, as I'm sure jamie does. They meter the steam output as you describe, @JUGHNE.

alexd

Took some more pictures last night of near boiler piping and main vents in basement (hope this isn't too many, just trying to respond to all of the questions so far). The main vent closest to the boiler is a "Hoffman no. 11 vapor vacuum" which is just above the differential loop. the only other vent I see is a "Hoffman 75H" towards the rear on the second loop.

Haven't drained the boiler yet or fiddled with the auto feed/sight glass but will work on that tonight. Still looking for a local steam contractor recommendation if anyone has one since getting this thing balanced sounds more complex than something I can handle on my own.

KC_Jones

First thing that jumps out at me....the pressure is too high, no it's MASSIVELY too high. That pressuretrol should be turned all the way down and honestly on that type of system should probably be changed to a vaporstat, you want to be below 1 PSI on these types of systems. The rest I will leave to people with more experience.

vaporvac

Do you know how your connected EDR compares to the sq ft of steam rating of your rads?

alexd

I do not. I counted the radiators (there are 29, 8 of which are in a sunroom off the house), but beyond that don't know.

vaporvac

There are tables in this sites library that will help you. Armed with that info, you can see if an over-sized boiler and/or lack of adequate main venting is to blame for you high pressure.
Are those sunroom rads in use?

Jamie Hall

Oh boy. You still have the Hoffman Differential Loop. That's good. In fact, that's very very good. Don't let anyone mess with it.

For main venting, you should add one or two Gorton #2s with that Hoffman No. 11 on an antler connected where Hoffman was.

Then you should go out into your system and find the crossover traps. They will be at the end of each steam main. There will be a pipe up, then 90 over to the trap, then from the outlet of the trap to the dry return. Make sure they are working. If there is any doubt, replace the innards.

You can do that while you are waiting for the 0 to 16 ounce vapourstat, which you absolutely positively must have to make this system work. It will never work properly without it. You may as well keep the pressurestat as a backup. Set the vapourstat to no more than 10 ounces cutout with a differential of 4 to 6 ounces. Don't compromise on this one. There is no way that a pressurestat can be set low enough to work with this type of system, and there is no way that this type of system will work at any pressure a pressurestat can be set to.

Get that vapourstat as soon as possible!

Abracadabra

4psi makes baby Jesus cry.

ChrisJ

Abracadabra said:

4psi makes baby Jesus cry.

4 PSI cut in, what's the cut out!?!
Someone thought they were running low pressure turbines off of the boiler or something.

alexd

How do I determine cut out?

Jamie Hall

Alex -- I've sent you a PM in reply to yours. If you don't get it, post here and I'll lay it all out here! I'd put pretty good money on the high pressure being almost all of your problem.

alexd

Got it, thanks Jamie!

Steamhead

That's not the only problem. This is a Dunkirk boiler, and once again whoever put it in bushed down the 2-1/2" steam outlet to 2".

And they reduced the header from 2" to 1-1/2" at the second tee, which means water will back up in there.

All together now......................

alexd

It's actually a Crown Boiler. Your other claim I won't dispute since I'm not totally sure what you're talking about. That said, the pipe diameter doesn't change anywhere close to the boiler, not sure what you're seeing that would indicate this.

ChrisJ

@Steamhead Who makes Crown boilers?

Jamie Hall

I'm not even thinking about the near boiler piping at the moment!

However, on a more general note -- if that poor thing really is running anywhere close to 4 psi, that means that it will be backing water out when the pressure starts to ramp up into the dry returns and the mains, both. At which point the auto feeder kicks on... which is why I suspect that the high pressure is at the root of the over fill problem.

Steamhead

alexd said:

It's actually a Crown Boiler. Your other claim I won't dispute since I'm not totally sure what you're talking about. That said, the pipe diameter doesn't change anywhere close to the boiler, not sure what you're seeing that would indicate this.

The Crown and Dunkirk boilers of that era look very similar. Look at the rating plate, if it says "Certified by DRC" or "Certified by ECR" or similar, it's a Dunkirk. I'm not sure how much cross-pollination there is these days between the two brands, but I do know Dunkirk used to make some Smith-branded boilers a decade or so ago. The certification was a dead giveaway.

Current-model Crown Bermuda series boilers have their steam outlets on top rather than the side, as yours does, and they're 2-inch. The installation manual is here, scroll down for the piping info:

http://www.crownboiler.com/documents/bermuda_installation_manual_2012.pdf

Dunkirk hasn't changed the basic design of their Plymouth series steam boilers in at least two decades. Here is their manual:

http://www.dunkirk.com/sites/default/files/3870.pdf

As to the pipe size reduction, look at the top row of pics, second from the right, the one with the close-up of the low-water cutoff. You can see a hexagon where the steam outlet pipe connects to the boiler. That's a bushing- a reducing fitting that screws into a pipe-threaded opening, to connect a smaller pipe.

Dave0176

The name plate clearly states certified by DRC, that'd be Dunkirk Radiator Corporation. I've worked on many Crowns of this vintage, seems a lot of plumbers in this area were Crown or some type of ECR, or DRC lovers, and all of them are always bushed down to 2" risers. Most piped in Copper.

This type of boiler with it's side outlets just seems like a **** child to make dry steam even when you follow their specs to the tee.

I service a small tenemant appartment house in Newark with two of these Crowns both being 150,000 BTU for each 700 sq ft appartment!!!!!! Plumber did use both risers and in steel, but he bushed them down.

alexd

Thanks @Steamhead. I found some history on Dunkirk-Crown that explains what you said above. They got into a legal battle in 2001 because of Crown's newly formed partnership with Burnham, and eventually Dunkirk stopped selling parts to Crown. This boiler was manufactured in February 2001, so it is still mostly Dunkirk parts. Here is the case in question:
https://casetext.com/case/dunkirk-boilers-v-crown-boiler-co-inc

The boiler that I have is Crown Jamaica (JBF-82SPD) and does have the "certified by DRC". The manual calls for 2 1/2" piping like you say, but is 2" leaving the boiler before expanding into larger distribution pipe further out.

Steamhead

alexd said:

The manual calls for 2 1/2" piping like you say, but is 2" leaving the boiler before expanding into larger distribution pipe further out.

Yup- knuckleheaded, like so many others.

All together now..................