over sized boiler; undersized header; no pressure; poor balance; noise

Papi_2

I’ve been reading the books, trying to think like steam, and it has been quite a journey. and I could really use some help . . . because I am a little stuck. We bought a 3-story frame house in Brooklyn NY about 6 years ago. The house is circa 1909, with one pipe steam. Shortly after we bought the house we had a plumber in and he recommended replacing the boiler - which we did (with a Weil McLain EG Series 65). He did me the good service at that point of pointing me to Dan’s books. It took a while, but eventually I read the books, consulted with some knowledgeable plumbers, and learn a little bit. But that was long after the new boiler went in. Last year I:- flushed the boiler- skimmed the boiler- replaced a half dozen radiator valves- replaced the main vents (with Gorton #2s) and all of the radiator vents (all with Ds to begin with)- installed an isolation valve in the Hartford loop just before the boiler, and a drain cock at the bottom of the loop to allow flushing- replaced the pressuretrol with a vaporstat and the 30 psi gauge with a 5 psi gauge- I clocked the meter and I am using 250,000 btu which is the rated input- I replaced the thermostat after much trial and error with a Honeywell FocusPro TH5000 (on most of the stats I tried – new Honeywell rounds - the power stealing battery wouldn’t charge . . . this one has regular batteries) I have the CPH set to one (as per the thermostat installation guide for steam application) So here is where I am at now:- the boiler is oversized by 33% . . . the plumber calculated my radiation load (474 SF) added a pickup factor of 33%, and then put in a WM boiler based on the NET rating . . . so the pick up was factored in twice. I am having a hard time understanding what this mean to me, though, in terms of cost to operate and system balance – can anyone help me here? The guy at WM Technical Service said the oversized boiler was costing more to operate; I’m struggling, though, with the idea of the conservation of work – whether it is under over or just right it is doing a finite amount of work keeping the house to setpoint – no? If it is costing me more to run, can somebody who is better than me at thinking like steam, and seeing the entire system, help me understand why? The guy at WM didn’t have too much to say about what happens once the steam leaves the boiler – he suggested I try putting questions on the Wall. I asked him if there was any way to de-rate the boiler, say through the gas valve adjustment; he said I could get maybe -10% that way but no more (I’ve turned that screw behind the thumbscrew cover and I don’t think it is changing the input per clocking the meter . . .) and he said there was no way to de-rate the boiler . . . (what, though, about doing something with the burner?)- the near boiler piping was put in with a 3” riser and a 2” header; the manufacturer calls for a 3” header- I have water hammer; not the worst I could imagine, but enough to keep the kids up at night (it doesn’t take much); I’m not quite sure if it is beginning, middle or end of the cycle; I think beginning and mid . . .- I don’t build pressure in the system! (So that new vaporstat is not doing much for me. . . )- my 3rd floor is colder than my 2nd floor and the 2nd is colder than the 1st- I’ve read the venting capacity studies and Dan’s books and I understand why you size the vents based on the size of the radiators and the amount of air being displaced; I just don’t understand why 99% of the world including the manufacturer Gorton says you size vents based on geography . . . Anybody have any thoughts?- I started to calculate EXACTLY what size vents I should have where based on the size of the radiators and the run up piping, and then I just said ”heck, I’ll vent the 3rd floor like crazy and see what happens' . . . so I built little manifolds out of 1/8” pipe and put 2 Ds and a C on each of the third floor radiators (that’s about the max of air that will vent through the 1/8” tap); I call this “mega-venting”; and it didn’t heat up the 3rd floor any quicker- That was last season . . . this season I noticed the hammer . . .maybe it was there last year but I didn’t notice it as much if it was- I figured the mega venting might be allowing too high a steam velocity (does the over sized boiler do this too?) and so I unwound that and went back to one vent per radiator . . .I’m not sure if this helped . . . I’d like to think so . . . just not sure . . . - I skimmed the boiler . . . even though my water looked clean, and the water line didn’t bounce too bad, I think this did help stop a lot (but not all) of the hammer . . . maybe I brought some oil back to the boiler off of all of the mega venting piping I put up on the 3rd floor last year . . . - I don’t build pressure! I took the vaporstat and the gauge back to the heating supply house and said “these don’t work, I never get a reading” . . .he put them on the test bench, blew in to the pigtail they are on and it showed pressure and cut the vaporstat in and out . . . so, yes, they work- I don’t think I have a leak in the boiler; I raised the water level up past the boiler into the riser and not leak . . . and I don’t lose water form the system- when it is real cold outside, or I jumped the temp set point up a whole bunch to get a long run time, then I get pressure. . . and the 3rd floor (when it had the mega venting) got hot faster than anyplace. - the stat is by the first radiator off of the biggest main (there are two mains) so this rad gets the steam first (even if the rest are not far behind). I’ve tried just closing the valve to this one rad and it doesn’t’ make much difference- if too fast venting of the radiator can cause problems, why doesn’t too fast venting of the main’s cause problems? Or can it?- how should I think about what it means for the boiler to be over sized?- why no pressure?- is it worth it to change the 2” header to the 3” called for by WM?- I know that the water hammer is notorious for sounding like it is coming from someplace different from where it is in fact coming from. I hear it knock pretty loud when I am by the radiator on the first floor that is just above the end of the “red” main (I’ve got a link below to a diagram of the distribution and radiators, and the mains are color coded). The place where it bothers us the most is in the boys’ room (this room is on the second floor and it is marked on the distribution drawing), where it can sound like a ping – ping – ping or something hard hitting something- All I want is even quiet steam heat to keep the babies warm, and failing that to at least understanding more of what is going on- pictures are attached of: 1) "Steam System" - a diagram of the steam distribution and radiators 2) "Near Boiler Piping" and 3) Piping at End of "Red" Main- There a two mains each of which has a parallel counterflow return. There are two other branches in the basement, for smaller amounts of rads, which don’t have separate returns. The main shown on the drawing in red is the one the heats up fastest . . . The first radiator off of this red main (it is shown as a purple branch going up off of the main) on the first floor is in the same room as the stat (on the opposite wall)- can anybody help?!recap if my problems and questions:- uneven heat- some noise- boiler oversized by 33%; what should I make of this?- header is 2” should be 3”; is it worth it to replace it?- I do not build pressure in the system on a routine basis; only when it is very very cold or I’ve set the setpoint up several degrees- If vent sizing should be based on the size of the rads, why is the geography method so prevalent?Thanks for any help you can send me!

Unknown

Pictures

Hi-  It might be a good idea to have a steam pro take a look at your system. Go to the " Find a Professional " Button at the top of this page and see if one is located near you.

From your post I gather you have made adjustments to the burner. Working on burners  is an area that I believe that only pros should handle as they have the experience and equipment to test and adjust your burner properly.

A couple of things come immediately to mind. Going from a 3 inch riser to a 2 inch header is about a 50% reduction is cross section area. I'm assuming this is a one pipe steam system? What are the size of the two mains?  You might also want to post some more pictures of your boiler piping from different angles. I can't tell for sure from the one picture of your boiler, but it would seem that your dry returns connect with each other above the water line and this could definitely cause problems. You don't want steam from one main cross flowing into the other.  They shouldn't connect until they are well below the waterline in the wet return.

- Rod

Papi_2

video of boiler and piping

Rod, Thanks for your reply. All I've done with the gas is clock the boiler, make minor adjustments to the gas pressure on the gas valve (guided by the person at the heating supply house), and gather information; I'm not going any further with the gas on my own. I'll likely wind up working with a pro, I'm just trying to understand as much as I can myself before doing that. The returns join up about midway between the header and the waterline (around the top of the boiler). This is a link to a home video that shows the boiler and the piping in the basement: http://bit.ly/8YB4VE I thought this owuld be a good way to show everything, but the file is pretty big which can be a little bit of trouble sometimes - if this causes I'll post more still pictures - just let me know. Yes - one pipe and the returns are dry. I can't get at the mains becasue they are insulated-I'm guessing they are somehting like 1 1/2" Thanks!Papi

Unknown

System Problems

Hi- I looked over the video (Wow! It is A BIG file!)  The video gives a

good overall picture of the system, and while you can pause it to study

individual areas, it lacks the ability of the still photo to be able to

blow it up and move slowly around the picture. However I do now have a

better idea of your system.

First of all do you have the book "The Lost Art of Steam Heating " by Dan Holohan?  If you do I will be able to refer you to certain pages which would explain things on certain items  better than I could.

Giving you advice on whether anything can be done with the over size boiler is beyond my experience so maybe one of the pros that know this boiler can help you on that.

Thee areas I can see some problems with are:

1. The header is too small.

2. The dry returns shouldn't connect.

3. The operation of the main vents is questionable as they should come off the top of the mains

4. The radiator laterals enter the mains at a 90 degree rather than a 45.

5. The boiler is way oversized.

6. Do you have a large scale pressure gauge? You need one that reads from 0-3 PSI. (The 0-30 PSI that came with the boiler still needs to be in place as it is required by code/insurance.)

7. The fact that the #4 problem is present tends makes me to think that who ever did the piping layout didn't have much knowledge of steam and that would make the piping sizing and pitch suspect.



I would suggest that you start with the returns as correcting these is quite easy and probably should get your system somewhat running. Being jointed above the waterline the two mains are cross feeding. Steam travels from high pressure to low pressure but with cross feeding rather than the steam moving down the pipe the low pressure is satisfied by the other main. This also can cause water hammer as the steam coming from the other main collides with the condensate in the opposite return.

To fix this  I'd remove the piping on the returns to where the elbow turns down towards the floor above the boiler. I would replace the elbow with a Tee (with a pipe plug) and then extend each return from that tee all the way to the level of the wet return where the each return would join the wet return. Since the return now join well below  the water level, the steam would not be able to cross feed.  On the down run use two sections of pipe on each return with a union joining them.   The reason for the tee (with a pipe plug) at the top\the down return instead of an elbow, is that this gives you an option of installing a main vent at this location if the present main venting proves unsatisfactory. Accomplishing this change should be quite easy. The pipe lengths and parts you should be able to get at Home Depot.

Let's get the returns straightened out first and then we can see how badly the system is affected by the other problems. Let me know if you have problems understanding the return layout. I apologize for not being able to put together a drawing for you as my computer has crashed and the computer I'm now using doesn't have draw program.

- Rod

Papi_2

follow up

Thanks again Rod for looking at this with me. Yes, I have the Lost Art and I've read it - I would like to look up any references you can point me to. I understand perfectly your description of how to repipe the end of the returns - that's what I'll tackle first. . . it makes good sense and sounds promising. I'll run down the other issues in time too.



Anyone out there have any thoughts about the impact of the oversized boiler or what if anything to do about it?



Thank you!

Unknown

Photos

Hi Again- Could you take some photos of the piping around your boiler and include the piping over the boiler? Also a photo of each main vent. I've been studying your video and system and need the photos so that I can point some items out to you.

- Rod

Papi_2

pics - near boiler and end of mains

Here are pics of the near boiler piping and the ends of the mains. What do you think? Thanks for all of your help!

Unknown

System Problems

Hi- Thanks for the pictures they are a big help.

I'm not quite sure where to start. Looking things over it's fairly obvious that who originally installed your steam system didn't know much about steam.

In a one pipe steam system, the piping is shared by the steam and the condensate (water)  Steam uses the top half of the pipe and water uses the bottom half. In reality it isn't a 50-50 situation but for our purposes it's easier to consider it that way. In designing a one pipe steam system care must be taken so that the placement of fittings and the arrangement of the  piping optimizes the movement of  the steam and water and keeps interference between the two at a minimum. On any section of pipe or a fittings you have to picture the flow of the steam and water and how each is affected. This helps you spot problems that may occur.



Radiator Laterals- One of the first things I noticed is that it appears that your radiator laterals are attached to the top of the mains. Page 86 & 87 in "The Lost Art..." discuss this.

I might mention that with the insulation in place it is hard to determine exact location of the fittings so I may have misinterpreted the photos. Using the criteria on page 86 & 87 I'd check each of my radiator laterals and determine how well they conform. The real proof is whether they work properly but knowing the configurations will help you pinpoint the source of a problem if it appears. While not ideal the laterals may work okay so I wouldn't worry about them at this point.



Main Vents.(Note"A") - Again it is hard to determine with the insulation in place but it looks like this comes off a tee and is also used as an elbow. The Tee is apparently on its side where it would vent (think 50-50) both steam and water. This may well work but again isn't ideal. Main vents should be on the top of the pipe as their job is to vent air and detect steam.  The fix would be to extend the main out a bit (See Note "B") and place the vent on the top. You wouldn't want to reduce the size of the pipe until after the down turn to the dry return. If there is a problem with the main vents at the present location.they can be moved to the "alternate position" (see the Return Drawing) where they should work okay.



Return Modification (See Return drawing) - We've discussed this earlier. I've made a further modification by add a tee instead of an elbow to the base of outside pipe. The allows for future modifications (possibly a drip off the counterflow main) Note the alternate main vent position.  I think modifying the returns should get your system operational. I think at this point the main thing is to get you through the winter and then next spring, when it warms up, you'll have more time to straighten out the other problems.



Counterflow Main-  From the picture it would seem that this is counterflow (?) and the returning condensate being dumped into the "Blue Main" probably doesn't help much. Since it is easily accessible to the Wet Return I'd consider dripping it.(See picture)

I'm really interested in seeing the results of the modification to the return, Hopefully that will make a big difference to your system's operation.  The "reduced" header still bothers me.

As to the boiler- I stay away from burners so I can't help you much there, Why don't you try posting  over in Gas Heating?  Mention the make and model of your boiler and that it is steam and 33 % oversized and ask whether it can be downfired. They have some pretty sharp people over there who might be able to help you.

- Rod

Papi_2

a few more things

Ok Rod, I'm taking this all in. Thanks so much for working through this with me! I will check out the heating board and see what anyone has to say about defireing my boiler. I will do the return repiping - not sure just when I'll be able to get to it, but I will do it. I was down by the boiler tonight and notice a few things:

- the return from the red main gets hot about 3-5 mins before the reutrn for the blue main gets hot

- the whole boiler firing cycle lasted about 8-10 minutes

- I notice a little noise coming from a spot where the red return (uninsulated at that point) touches the red main (insulated); it wasn't a lot of noise; I wouldn't htink it is my prime "culprit"; but I could make the nose stop by holding the pipes there; I'm showing it in some attached pictures

- the pipe you identified as a counterflow main that comes off of my blue main - it heads to the back of the house (the brown #1 branch on my drawing) then does a 90 off to the yellow branch; where the yello branch hits the side wall of the house at does a 90 again turning to towards the back of the house and running throuhg a basement wall; right at that point there is a plug in the end of the line . . . maybe it used to be a vent? It is shown in the attached picture



I thought these observations might be worth sharing.



Thanks again!



Papi

Papi_2

please disregard

Papi_2

please disregard

Unknown

Expansion Noises

Where the pipes touch you might want to put a piece of plastic between them. A piece cut out of a plastic milk bottle works well for this. How well do the radiators on the counterflow main work?  From qa design standpoint you should have a main vent at the end of the counterflow main.  Where it is capped off might have been a location for a vent though like the vents at the end of the mains the vent hole ideally should be in the top of the pipe.

- Rod