New owner 1923 steam house. Hoffman system? Not working 100%

adg

I've recently moved into a 1923 house with some sort of Hoffman steam 2-pipe system. I'm hoping you can help me figure out what I have and see if I can get it working better.

Currently the system is running fairly well. House heats up and family isn't complaining. 9 radiators on 1st floor, 6 on 2nd floor. Issues are two radiators aren't working on main floor, and a far run 2nd floor radiator takes too long to warm. No knocking, no weird noises.

I haven't yet tweaked anything myself yet, but the heating guys did and I'm pretty sure they didn't do it very well. Other things I believe are important... venting seem lacking, pressuretrol is too high, piping seems a bit strange and the hoffman trap isn't doing anything. Something happened in the past and I guess it's disabled for some reason.

So a little history... In my quest to try to fix the two radiators, I've had out two local heating companies and the analysis was painful. Their lack of knowledge, led me to start researching, reading the Dan books, and reading this forum. I knew nothing about steam heating until a couple weeks ago, and was relying on the heating companies. I guess they are the knuckleheads, wanting to get a good head of steam (high psi) going to clear out the radiator. Wanted to add a trap to the wrong side of the non-working radiator, since he didn't see any on the rad. I had to tell him the other side has the trap on it!

When I moved in the water level wasn't keeping well, and refills were a problem. I thought venting may be doing it and the heating guy noticed the dry return had a plug where a vent was supposed to go. He added a vent there and replaced another main vent. I do believe after doing that, refills are not happening as much. No data to back it up yet. Just one vent on the dry return and one vent on the end of the loop of the main. Dry return vent hisses. I believe I need more.

My system has some Hoffman 17C traps, a Hoffman No8, another a Dunham 1E. Someone on the forum suggested a No8 trap indicates I may have a vapor heat system? I also have a very large main return trap that looks like this Hoffman boiler trap return. https://heatinghelp.com/heating-museum/hoffman-boiler-return-trap-patent/. It has similar plumbing, but more complicated. What's good is much of the plumbing looks original. The boiler is fairly new, and the copper header was done at that time.

For the radiator problems: Radiator #1 is completely cold, Radiator #2, sometimes gets slightly warm in the corner. #1 is the first radiator on the main, #2 is the second. Third radiator works. I believe #1 isn't working because the porch settled and the condensate pipes are not pitched right. Also the trap could be bad. I believe #2 isn't working cause of the trap, could also be pitch of condensate pipe. Going to replace the cages in each and see what happens.

I'm hoping someone can take a look at my boiler setup and help me figure out what I have. I wouldn't mind getting the original piping w/ hoffman trap working again. I'm in Grand Rapids, and contemplated reaching out to the steam whisperer for tweaks/consulting too if I get over my head!

Thanks!

Alan

wmgeorge

Do you have Dan's first book "The Lost Art of Steam Heating" ? If not please get and sit down and read. I had worked on steam, hot water and other types of heating for 50 years or so and I learned. Sounds like your local people do not have clue.

adg

Yeah, I have that one, I am not through it all yet though. I did read through "We Got Steam Heat:, and "A Pocketful of Steam Problems". They were simpler reads. I'm having to read and re-read the Lost Art of Steam Heating to understand some of the paragraphs though and try to compare it to my system

Jamie Hall

Other than being a Marsh return trap, not a Hoffman, the general principle -- and the overall concept -- is much the same. I rather wonder if it still works, though. The Hoffman version had provision for lubrication -- can you find anything like that on it?

Systems equipped with that type of return device did not need to operate on the very low pressures of a true vapour system, although there was no harm if they did.

I'm sure you will discover, if you haven't already, that the near boiler piping on and in the vicinity of you boiler leaves something to be desired.

The chances are that your two rather chilly radiators have trap problems, but they may also have pipe pitch problems. Pipe pitch in the supply lines is likely to give rise to water hammer, but in the return lines it usually doesn't hammer -- but if the pitch is far enough out of whack to really trap water, it may make the radiator heat poorly, if at all, due to blocking the air from leaving.

The main vent on your dry (high level) return is really critical. It's almost impossible -- except for the hit to the budget -- too have too much, and you may want to replace what you have with a Gorton #2.

You also mention a main vent on the steam main itself. That is a little unusual on this type of system -- more often there were crossover traps -- but it needs to be at least adequate, too.

delcrossv

I'm not up on Hoffman systems, but doesn't that boiler require an equalizer? Or does the return trap take care of that?

Steamhead

Second that. Your main and return vents are too small.

How long is the steam main, and what pipe size?

Jamie Hall

delcrossv said:

I'm not up on Hoffman systems, but doesn't that boiler require an equalizer? Or does the return trap take care of that?

It does indeed. And that's not all that's wrong right around the boiler...

adg

Those mains run in a loop around about half the house basement. That loop is to be about 73 feet.
mains are 3", header is 2.5, condensate is 2.

I attached pictures of the Marsh trap. The trap looks to be in a state of hibernation. At the top there is a screw plug, probably for that lubrication you were talking about.

I noticed something else now too, because of the copper header, I believe a solder joint may be bad on the right side of the header. I think I hear steam coming from it. It could have happened during that last high pressure run the heating guys did, or maybe it was there for a bit. Gonna have to get that looked at, or rebuild the piping with cast iron

Jamie Hall

That plug will have been for a vent, most likely, not a trap.

adg

I found an inspection report photo of the boiler and that solder joint may have been questionable back then, but now is bad.

adg

@Jamie Hall That plug was on the top of large Marsh return trap. The picture is of the top head of the return trap. You can see it better in this pic

delcrossv

Jamie Hall said:

That plug will have been for a vent, most likely, not a trap.

Can you elaborate on that? This Dan video was enlightening. Seems one of the returns is in the wrong side of the check valve?

https://youtube.com/watch?v=j9FfGBXxDVE

adg

There's one more thing, when the vents were replaced, this vent was taken off the main and replaced with whatever type is up there now. The old vent was a Dole No 55, not sure how old it was. That vent used to make a bunch of noise when it was the only one. Now with the new vents the dry return makes noise.

I'll see about ordering the Gorton #2.

One other thing, the way my dry return vent is piped, based on the Gorton #2 graphic below at supply house may be not great either, not really sure of the impact of that though.

adg

I found the Dole air vent literature, not sure why they replaced it.