Just moved in

johnbrodo

We just moved in to a house with a steam heating system. It is a one pipe system in a 1800 sq ft 2 story house. The boiler is only 6 years old and appears to run very well. Overall the heating system seems like it works fine so I guess my question is more about efficiency... It seems like it takes quite a bit of time for steam to make it's way to all the radiators and the pressure gauge (pressuretrol) tops out at just about 4 1/2 psi once everything gets going. There are two main vents in the basement and then, of course, the individual vents on the radiators... how can I tell if the main vents in the basement are working? From what I have read 4 1/2 psi means that there is a problem and the air is being trapped somewhere.

I'd hate to mess with something, if things are working ok, and end up with bigger problems

Any ideas? I can provide more detailed information if needed. 



Thanks!

Dave in QCA

Need more information and pictures

We'll be better able to answer your questions with pictures of your boiler, radiators, vents, etc.



But, in regards to your some of your questions, you are partly right.  If the pressure goes high before the radiators have heated up, then there is air being trapped and or not vented fast enough.  However, if the pressure only goes up after everything has heated up, it only means that you're making steam faster than the radiators can condense it, or your boiler is a bit over sided, but that is better than undersized (within a margin).  The big issue here is that your pressure trol is set too high.  It should shut of the boiler when the pressure reaches 2 psi, or perhaps even less.  A residential boiler should never exceed 2 psi, and most systems will work fine with 1 psi or even 8 oz.   So, turn that pressure down!  That means that the boiler may cycle off and on during a long steam cycle.  The only way to prevent the pressure from going too high is to turn off the fire, and then when the pressure has dropped a little, the fire comes back on.

We'll wait for more information......

johnbrodo2

pictures

Thanks for the quick reply. Here are some pictures. The pressure definitely goes up before the radiators heat up. Will it hurt anything to try turning the pressure cut in and differential down? It seems the worse that could happen is that the boiler keeps shutting off and the radiators don't get hot. Then I could just readjust it if I have to, even set it back to it's current setting (which is what it was when move in - cut in is set to 8 psi and the differential looks like it is at about 1 1/2). The pictures aren't great. I'd be happy to take more, or more specific ones if it will help.



the pictures are of the boiler, close up of the pressurtrol, a few radiators and vents, and the two main vents.



Thanks again

Dave in QCA

Bad News

Well, hate to say it, but there are some serous piping errors on your boiler.  The horizontal part of your header is to low.  It should be at least 24" above the water line.  Second, and this is really a BIG deal, there is no equalizer line!



Your main vents look like antique Hoffman vents.  It is likely that they are stuck closed and not doing anything.  I don't know the length and diameter of your steam mains, but I think I'd start with a Gorton #2 on each, or perhaps a Hoffman 75 on each would be sufficient.  When the boiler starts to make steam, it should take about 2 minutes for steam to get to the Main vents.  If it is slower, they are not venting fast eneough, especially if you are buidling pressure at the same time.



After the main venting and boiler piping is corrected you can see how the balance is then.  If still out of balance, I think I'd try setting all of your vents at 4, then increasing the ones that are slow and perhaps even turning down one if it seems to be faster than the rest.



Do you have a copy of the Installation Manual for this boiler?



EDIT, found the manual, here it is.

BobC

Pressure to high

Steam systems run a lot better at low pressure, dial that front tab down to 0.5PSI with the adjustment on top of the pressuretrol, the inside dial should be set to 1.



Your main vents may not be working and they are probably to small. It looks like they are mounted on nipples, that's good because that one against the joist has to move so a larger vent can be installed. How long are the steam mains and what size pipe (circumference is fine). The radiator vents you show in the pictures are very good vents but once we have the main venting sorted out we will probably be turning them all down. You really want to vent the mains fast and the radiators slowly.



The near boiler piping is not right but lets address the venting first to see where that gets us.



Bob

johnbrodo2

pipes to main vents

Thanks again for the quick responses and link to the PDF!



I measured the pipes in the basement. The distance to each of the two vents is about 30 ft. That's 30 ft to vent 1 and 30 ft to vent 2 so 60 feet total. The pipes are about 7.5 inches in circumference.

I could head down and turn the pressure controls down right now. (we are using the wood stove today because it's not that cold.) but should I wait until I replace the main vents?

BobC

i missed that completely

Dave, I saw the bad piping but missed the missing equalizer - time to clean the glasses. That is more serious than the low header but the homeowner didn't mention any real issues other than slow to heat radiators. Sometimes the steam gods are kind to us.



Does this boiler show signs of water hammer or serious surging in the sight glass?



Bob

johnbrodo2

site glass

Nope, the water in the sight glass doesn't jump around around much at all, although it does slowly move up and down, I marked the high and low points and it always stays within them... it doesn't "surge" it just will slowly get a little higher or lower.

I have not noticed any water hammering in the basement. One of our really long radiators is slanting in the wrong directions so that it bangs a little when it really heats up. I guess water is pooling in there. I intend to jack it up a little to slant it in the right direction

BobC

main vents

30 ft of 2" pipe is about 0.65 cu ft. It doesn't look like you have a lot of headroom there so I'd start with a single Gorton #1 main vent (0.33 CFM)for each main, you might need two on each main but start with one and see how that goes. Those are about 2" in diameter and 3-1/2" high so you might have to use some nipples and elbows to move things around, just make sure it's all got some slope so any water can find it's way back to the steam main.



Before changing the vents why don't you time how long it takes those mains to heat up. See how long it takes the steam to get from the boiler outlet to the end of the main, then repeat the test when the new vents are on.



Bob

johnbrodo2

Thanks

Thanks a lot. I will try that. Should I wait until I have replaced the vents to turn the pressure cut in and differential down?

BobC

Now or later

Try lowering the pressure now, if it causes problems just raise it back up where it was till you get the vents.



Bob

Rod

New Steam System

Hi- Welcome to the Wall! As others have mentioned you have a real jumble of piping. What usually has happened in these situations is that the original installers knew what they were doing but since then, what we (for politeness) call “knuckleheads”, who didn’t have a clue as to what they were doing, made “mickey mouse” modifications to your system.  What needs to be done is to remove the “modifications” which will then get your steam system operating economically and comfortably.



It would appear that you have what is called counterflow steam mains. In that attached photos, there is a drip line (labeled “1") which runs down from the steam main labeled “B” . There seems to be the same setup on the steam main labeled “A” but in this case the drip seems to have been capped off.



The first thing I would do is to use a carpenter’s bubble level and check the slope of both steam main “A” and steam main “B”.  If the overall main piping slopes towards the boiler, then the main is called a “counterflow main”.  If the main slopes away from the boiler (meaning the end of the main above the boiler is higher than the far end of the main away from the boiler),the main is called a “Parallel Main”.  What we are doing is checking to see whether the original slope to the mains has been changed and/ or “mickey moused”.



I’ve labeled with the number s 1,2,3 what look like return lines. Number 1 is the drip line for main “B”. Where do the pipes numbered 2 & 3 attach to the system?  I’ve attached a drawing of a typical counterflow system with drip lines. Its called “counterflow” because the steam goes up the main and the condensate (water)  returns to the boiler in the opposite direction.



As others have mentioned your near boiler piping also needs to be corrected. Here’s a link to a good video on near boiler piping and why the proper configuration is important:

http://www.heatinghelp.com/article/107/Steam-Heating/118/Steam-boiler-near-boiler-piping

You have a good boiler as it is the same model I have!

The need to replace those mickey mouse main vents has also ben mentioned and that is probably the first thing to do. You need to get your steam pressure down as this wastes fuel! Residential steam systems operate at a maximum steam pressure of 2 PSI!



There are also some really good books on stem heating in the Shop section of this website. I would recommend you start out with “We Got Steam Heat!” It’s written for homeowner new to steam heating and has a lot of tips on getting the most out of your system. This book pays for itself over and over. Here’s a link to it:

http://www.heatinghelp.com/products/Steam-Heating-Books/25/61/We-Got-Steam-Heat-A-Homeowners-Guide-to-Peaceful-Coexistence

- Rod

johnbrodo2

counterflow

I think you are right. Pipes A and B are supposed slope back towards the boiler, although I think over the years, and due to some laziness or lack of knowledge things where adjusted /replaced and now it almost perfectly level or slightly sloped in the wrong direction in some sections. Especially the main you labeled "A". If you notice the pipe that goes vertically from the boiler to main A, I think someone used a stock size piece of pipe, didn't bother to cut it, and it is so long that it raises the horizontal pipes for main "A" near the boiler to a point where they are higher then points in the main further down the line...

And the drip lines 2 and 3 connect directly to mains A and B, at the end of the line, just below the main vents for each. 2 goes to "B" and 3 goes to "A".

I will try new vents for sure... see how things go, maybe get some one in to help us fix the piping near the boiler.



I do have a copy of "we got steam heat". In fact, I just got it, and that is how I found this website.



Thanks a million

Rod

Mains

If they are sloping away from the boiler and have drip lines at the far end of the main that is fine as they have been converted to parallel flow which is better as the steam and condensate get along better together flowing the same direction. Counterflow was an earlier type of system. It was easy to install as there as return piping wasn't necessary.



Determining slope with a level-  If your pipes are clad with insulation just use two nails of the same length. Poke the nails in the bottom of the insulation till they touch the pipe and then place the level on the nail heads.



Definitely increase the Main Venting as the vents you have now are way too small!

Glad to hear you have "the Book". I just ordered a second one as I gave the other away. Afterward I felt rather bad about giving the old one away as it was a great friend in that it helped me out a lot and saved me at least 100 times its value.

- Rod

johnbrodo2

One more ??

OK, Thanks again for all the help. Just one more question...



I went down and looked at the old main vents. They appear to be Hoffman no.16 vents. Now, just to double check, I want to ask about the replacement vents.



Does the Gorton #1 make sense? Would I need the 3/4" x 1/2" #1 or the 3/8"? I am guessing the 3/4" x 1/2" but I am not sure... Let me know if you need any other information.



Thanks again. I really appreciate it.

Rod

Main Vents

Hi- Get the Gorton #1   3/4 x 1/2  - the male thread is 3/4 pipe and inside thread is 1/2 female pipe.  The Hoffman #16 vacuum vent is obsolete and about 1/6 the venting capacity of the Gorton #1. Keep it though it is a museum piece!

If you use Teflon tape on the threads, start the tape wrap back about 1/8 of an inch from the end of the pipe.Doing it this way it is less likely for little pieces of tape to fall off. These pieces of tape can stop up your vent orifices.

Don't worry about asking questions, that's how we all learn!

- Rod

johnbrodo2

Thanks

Thanks so much!