no hartford loop, equalizer or main vents - but no big issues?

sphen

hi there -



so i have read "we have steam heat" and now onto chapter 7 of the lost art of steam heating - excellent books -- and now im starting to look at my system and have a bunch of questions!



first off the system seems to be working well - except for the fact that right now it is building too much pressure (5 psi) before shutting off at pressuretrol - but i think i need to clean the pigtail again. but onto the main event with pictures...



i was looking at my system and i dont see a hartford loop, equalizer or main vents... the system doesnt have any hammering though - silent except for the shrieking of air vents on start up and cooldown. i get some spurting for air vents but think this could be high pressure and possibly level of the radiators. here is a quick sketch with some dimensions..

<a href="http://www.flickr.com/photos/sphensilhagen/5321596610/"><img src="http://farm6.static.flickr.com/5241/5321596610_cf6af87b46.jpg" width="500" height="410" alt="" /></a>



best i can tell the pipe coming out of the top of the boiler is 2" or maybe a bit bigger -- the headers up top are definitely 2". the return back to the boiler is 1.5". in the sketch the little black things at the end of the steam mains are where i suspect main vents were as they are capped. there is only radiator that has been taken out of the house and the pipes still exist and is capped.



there is an auto water feed and a low water shutoff - both seem to work. while the boiler fires i do get the water line moving in the glass quite a bit.



so i guess my questions is -- how is this working without those features? reading the books it sounds like they are almost required to get the system working well. should i bother adding main vents or would that maybe open a can of worms? the boiler takes a good 10/15 min i think yo get the radiators pumping and i do seem to be burning alof of oil - but we keep it cool in the house and its not that bad. and there really is not much sound other than the vents -- and a nock or two when the whole system cools down.



some more pictures:

<a href="http://www.flickr.com/photos/sphensilhagen/5320994715/"><img src="http://farm6.static.flickr.com/5127/5320994715_86d8f67967.jpg" width="333" height="500" alt="" /></a>

<a href="http://www.flickr.com/photos/sphensilhagen/5320993873/"><img src="http://farm6.static.flickr.com/5124/5320993873_481cfe31a5.jpg" width="500" height="333" alt="" /></a>



some stats that i could try to read off the dirty sticker on the boiler:



utica steam boiler

556 NET IBR

1.7 Gal/Hr

178 Valve Capacity



for ref - i calculated a total of only 166 EDR for the rads in the house..

nicholas bonham-carter

oversized utica steam boiler

how does the piping you have compare with the mfg's installation instructions?

what sort of burner is that? maybe it can be down-fired.

you always need main vents. get a good gauge on there so you know exactly what your pressure is.--nbc

BobC

Pigtail?

What is the pressuretrol set to? The front tab sb at 0.5PSI with the inside wheel 1PSI, that would let the boiler cycle between 0.5 and 1.5PSI. Is the boiler shutting down on pressure? As oversized as it is it should be cycling off on pressure. If it is cycling off on pressure The pigtail might well be fine.



The gauge on the boiler may not be much good in the lower end of the scale, does it read 0 when the boilers been off for a while? If you don't think your gauge is reading right, I'd install an auxiliary

0-3PSI gauge and keep an I eye on it when it fires up to see what the

pressure really is



The piping is all wrong but playing with boiler pipes in January can be dicey. .If the pressure really is around 5PSI with the pressuretrol correctly set, you want to replace that pressuretrol.



Is your main steam vent working and is it large enough? Put a level on the radiators and shim them if you have to, just enough so the water can find it's way back to the boiler.



Think about redoing the piping in the spring.



Bob

BobC

venting

I took another look at your post and noticed you found some capped main vent ports. You need main vents on that system for it to work right. If your sketch is right it looks like you have a single pipe parallel flow system - mains are highest above the boiler and slope down as the main goes along.



How long is each of those mains? With the length of the main and the diameter of the pipe you should be able to calculate the volume of air you have to vent. They don't look all that long, maybe you can get by with a couple of Gorton #1's. Remember you want to vent the mains quickly and the radiators slowly.



Adding main vents can do nothing but help. Also figure out if that 5PSI is real and get it down to 1.5PSI as I mentioned in my last post. Do you know how old that boiler is? What model is it?



Bob

sphen

more detail...

only thing i can find on the boiler as to model would be OU500ST - date - i am assuming it is at least easily early 1980 if not older as some of the maintenance states early 80s.



the mains seem short -- say only 10-12 feet out and then back.



so im not sue how the IBR translates to the EBR i calculated -- but could it be way oversized? should i ask to get the burner downfired a bit? it does cut off with pressure all the time.



about the pressuretrol - not sure if this makes sense - but i had a guy come out and take a look at it as ive been trying to find someone local who knows boilers. he cleaned out the pigtail - said there wasnt much in there but cleaned nonetheless - afterwards i watched it go through a heat cycle and it was working beautifully -- about 1.5psi it cut out and then back in a little less than .5 according to the 30psi gauge. BUT -- i checked on the next cycle it went through and i dont know if i was just lucky but i caught it do something.. while it was heating and pressure was steadily building - the pressure gauge surged up a few psi and then went back down. ever since it now cuts out at over 5 psi. i dont know if it wsnt cleaned out fully and something got back in or what -- but i havent had a second since the holidays to take it off and clean it out again and test.

Jamie Hall

If it ain't broke...

don't fix it.  Worry about the near boiler stuff when and if you replace the boiler.



Main vents will, however, help a lot with the shrieking radiator vents (unless you mind moving the shriek to the basement!).



There's something odd about that pressuretrol behaviour... best to check on it and get it straightened out.

BobC

More venting

With short mains like that you don't need a huge amount of venting, but the Gorton #2's are cheaper than a lot of the smaller vents (like Hoffman 4A's or VentRite 35's) and you really want those mains vented quickly. Are those plugged main vent ports 3/4' inch? You can get Gortons with a 3/4 (male) with a 1/2 (female) thread and they work for a lot of applications. This chart that one of the guys posted should help.



As we have said earlier you don't want to mess with the near boiler piping in the depths of winter, leave that for later. get every thing else working right, it's very likely this boiler worked pretty well for decades piped just the way it is now.



Bob

sphen

i agree...

totally agree with if it aint broke -- was just curious as to how this was working seemingly ok with so many faux pas! sounds like i will pursue getting some main vents in and leave it at that -- ill get a 1-3psi gauge and try to figure out what is going on with the pressuretrol. thank you...



other question though -- on a one pipe system like this etc -- would a vaporstat work?

BobC

Typo

When i mentioned Gorton #2's that was a typo on my part, I meant to say Gorton #1's. The #2'2 have 3X the venting capacity and are not needed for your mains - they are also at least twice as expensive as the #1's.



That boiler may be old enough to have a large enough steam chest to mask the problems you would have with a modern boiler. Best to leave sleeping dogs lie unless you enjoy the excitement that can be had by cracking things loose from a 30 year old boiler.



Addressing the venting and finding out what pressure you really have probably covers the low hanging fruit on this system.



Bob

Jamie Hall

In a word...

yes.  Although I would use the 4 psi max. flavour of vapourstat rather than the 16 oz. one (that's meant for vapour).  Don't have the part numbers handy.



But do figure out why the pressuretrol is being flaky first; changing to a vapourstat won't help that!

sphen

thanks!

you guys have been great -- thank you!

Charlie from wmass

My bet

the pigtail is dirty and the burner is downfired. Down firing masks many piping issues.

Dave in QCA

Dry Return Piping

I beleive your dry return piping set up was once considered acceptable.  Since you have no wet return, there is no chance of it springing a leak and draining the boiler.  The entire piping loop is essentially acting as the equalizer, (sort of).



Hoffman Specialty shows a piping diagram for this kind of system in their publication that was last updated in 1999.  Hoffman is pretty reliable, but they also appear to be the original source that proclaims that all vacuum devices should be removed from a system when it is converted from coal to oil or gas, and I am still suspicious of the accuracy of that advice.   I am attaching their publication below.  See page #3.



As others have stated, your missing main vents are critical and need to be replaced ASAP.  I suspect that you will see much improvement in your system when that happens.  Also, all advice on this thread regarding vaporstat is good. 

As others have said, your boiler appears to be over sized, and I am sure that it probably is.  However, your system EDR seams to be very low.  Your diagram indicates 7 radiators.  At the EDR your state, if you have standard 3 column 38" tall rads, they would be a little less than 5 sections each on average.  That just seems way to small to be accurate.  Tell us more about your radiators, perhaps give us a picture or two.

sphen

update...

thank you guys again for all the help - this has been a great experience. wanted to update on a few issues



i sucessfully had cleaned out the pigtail again and this time dismantled everything and repiped above the pigtail to work with a new vaporstat 0-3 psi gauge and the 0-30 psi gauge. adjusted with 1.5 main and 16 oz diff - and everything works like a dream!



my boiler is now shortcycling quite a bit once up to steam. it runs for 15-20 min then when it builds pressure it will run for less than a minute and then be off for pressure for a maybe 3 or more minutes. i guess this isnt the worst thing but was thinking if the nozzle was changed to be a bit smaller this might get a bit better.



i have not put in the two main vents that have been missing on my system yet though. i wanted someone else to do it and finally got the estimate -- but now am not sure what to do as it seems he is quoting over 11 times that of what the parts are. seems a bit steep considering it seems cut and dry to me. i could attach a pic of the plugs in the steam main where the vents would go - maybe they are just rusted in place at this point and will be impossible to get installed? is it stupid to tackle myself?



also in more reading and listening to the system -- the bubbling in the rads and air vents etc - i am thinking that the boiler should be skimmed -- now ive had the house for 3 years and nothing like that has ever been done - should be a yearly thing? im alsmost thinking that the dirty water might have clogged the pigtail to start and is the root of all these little issues...



i will followup with a couple pictures when i get home...