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Angled riser coming out of boiler

Diar Member Posts: 50
Thanks Steamhead! I'd love to get a drop header.

One thing that I find strange about my system that I've discussed with you in a previous thread was that in order to reduce the short cycling on pressure / allow the steam to get to my radiators, I needed to open up the adjustable vent-rite #1's to their full setting / 8. If I try to balance the system by reducing the venting rate at any of the radiators, the boiler shuts off on pressure faster and the radiators don't heat well.

Based on your advice from the previous thread, I downfired the boiler 10% and got large main vents, but it didn't help this situation.

Do you this might indicate that:
- the boiler is still overfired?
- the boiler is producing wet steam?
- incorrect readings on my vaporstat, due to placement, etc?
- there is something wrong with my piping / radiators?


  • Diar
    Diar Member Posts: 50

    Hi All,

    I've been having significant problems with my new steam boiler, a WM 480.

    Here are the details:
    - short cycles on pressure
    - sometimes cuts out on low water ( its always right on the edge of cutting out on low water ).
    - the sq ft steam output is matched to the radiators
    - it has a vaporstat installed 1" above the water line that is set to 16 oz. ( highest setting )
    - it has the right number of main vents, but may require one more on a long main which doesn't get as hot as fast as the other two mains
    - and finally, the single riser coming out of the boiler extends out of the boiler 5" before going on a 45 degree angle to join the header which is ~28" above the boiler.

    My main guesses as to the cause of the problem are:
    - the 45 degree angle in the riser is pushing water into the system / causing extra pressure ( I don't have banging, but I do have really long steam mains )
    - the vaporstat ( as well as pressure gauge which share the same T that leaves the standard location on the boiler ) is installed too close to the water line as to get an invalid reading.

    However, I _really_ could use some help fixing this issue.

    I've replaced my old boiler this year, which was grossly oversized (5x) and I'm still on the verge of selling my house because I cannot afford the $1600 / month heating bills I'm paying, which are as bad if not worse then my old boiler.

    Please help!
    - Diar

    ps - I've attached a couple of pictures of the current setup.
  • has the boiler been

    Wondering if the boiler been skimmed? I'm not talking about if its been done one time. May take more than dozen times to get it clean with skimming... Not much room above the boiler for drop header...
  • Daniel_3
    Daniel_3 Member Posts: 543

    I would say it looks quite easy for water to get into that tee for the pressuretrol, vaporstat, and gauge and just stay there forever. I would change that 90^ into a straight coupling keeping the controls higher. The tight basement ceiling seems to be playing a major part in keeping you from restraining water carryover even though the near boiler boiler looks well pitched and properly done. The skimming situation could be causing all the trouble.
  • Dale
    Dale Member Posts: 1,317
    piping details

    I certainly agree with the skimming post. I think that the minimum rise from the supply tapping to the header is too small,this could be fixed by an immediate rise and back down to a drop header. I also don't like the details of the control/gauge manifold header. I think the manifold header should be above the boiler sensing tapping not below it. This piping needs to drain. I think there should be a pig tail protecting both pressure controls and the gauge not just the center one. So, first do the cheapest thing and fix the little ctrl/gauge header, next skim, next the install the drop header
  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
    Another problem

    is that you took your steam connection from the front tapping. When Steamhead and I installed our first 4-80, we noticed a baffle in the front tapping that is supposed to act as an air separator if the boiler is used for hot-water. This would increase the velocity of the steam passing thru it, which might result in water being carried into the system. We used the rear tapping for the steam connection since it is wide open, and the steam velocity thru it is lower.

    We also mounted the Pressuretrol and Vaporstat on the top of the boiler instead of the front. This keeps them away from the waterline.

    We have pics of this job somewhere, and will post them when we find them.

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  • Dave_4
    Dave_4 Member Posts: 1,405

    Thanks to everybody for your advice.

    The boiler was skimmed once and the water looks pretty clean and the water line doesn't surge more than 1/2". Its certainly worth trying to skim to see if the situation improves. If it stops the short cycling, then I'll assume I 'll need to skim again if the short cycling starts happening again. However, if it doesn't improve, would I continue to skim it again or would I assume that skimming isn't the issue?

    Raising the control manifold header should be simple enough.

    Installing a drop header / changing the tapping isn't going to be easy, so I'd probably only do this if necessary. I'm not experiencing any banging ( except on the coldest days ), so is there a good way to tell if this is necessary?

    I'm still curious about whether the riser at a 45% angle is a valid way to achieve the boiler's riser height spec OR whether this means that I've effectively lost height in the riser? Any clarity on this would be great.
  • wondering...

    After re-reading the thread.... Wondering if the old boiler was 5 times oversized, meaning, was it in the pit? One time skimming is never enough on the new boiler with old piping system.... Sight glass movemet is nothing compared to what going on inside the steaming cycles...
  • Dave_4
    Dave_4 Member Posts: 1,405

    Nope. Same platform. I think I overstated the old boiler's size a little. The old boiler was an eight section WM boiler with almost identical sections to the new boiler. Don't know too much about what came before the eight section boiler, but I'm sure the piping is old and still a little leaky, since it chewed up 168 gallons over the winter.
  • Dale
    Dale Member Posts: 1,317

    Sorry,I got going and didn't speak to that. I think that the issue is the lack of total riser height not the 45. The key is the WM min. riser height. The steam is going in the correct direction and is the main header is sloped a bit to the equalizer it should drain ok. If the easier fixes don't solve the problem it looks like you have enough ceiling height for a connection to bring the supply up and back down to make a drop header out of your current header. Since you have a flange connection it will be a little easier.
  • Diar
    Diar Member Posts: 50

    The total riser height is proper / a couple of inches above the min riser height of 24".

    Its hard to tell if the main header is sloped to the equalizer, one link after the last riser is almost flat / might be ever so slightly leaning away from the equalizer, but the last link before the equalizer is heading down towards the equalizer. Not that I'm saying that it is, but even if the header was flat / slightly sloping away from the equalizer, would it be a major issue?
  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
    W-M 4-80 install pics

    Here they are. The first shot is of the front of the boiler, showing the drop header from the front and the control setup. The pressuretrol and gauge on the right are the usual ones. On the left are a Vaporstat and a gauge that reads up to 1 pound. They're both installed on brass pigtails threaded into 3/4-inch brass nipples extending from the top of the boiler's front section to reducers at the jacket level, so the boiler water's wave action cannot affect them, and if one gets plugged it will not affect both controls.

    The second pic shows the drop header. We came out of the rear (unobstructed) tapping with 4-inch pipe, up about 30 inches, then down and across to the header location. This setup produces bone-dry steam.

    If you don't have 30 inches, just do the best you can.

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  • Daniel_3
    Daniel_3 Member Posts: 543

    That is beautiful. I like the pressure control set-up where you have it, nice work.
  • Brad White_172
    Brad White_172 Member Posts: 53
    I agree with Steamhead and Dale

    The initial height is asking for trouble, more than the 45 elbow. That it may be right at the 24 inches, it would be nice to do better.

    A dropped header would help to recover some of that height, Diar. You seem to have room on the right-hand side to do that.

    Your instrumentation (gauge, limit and vaporstat) are practically below waterline and that cannot be a good thing as Daniel noted. I would move them up, well above, as Steamhead and Daniel suggested.

    I also agree that the boiler must have been in a pit at one time. Not the last one, but maybe the one before that. What is the actual "A" dimension? (Waterline to lowest steam-carrying pipe)?

    A good "A" dimension plus at least a 24 inch initial rise from waterline to header -which you say that you have- is the best place to start (absent better instructions from W-M, which should always be followed).

    You mentioned once that you are in or near Boston. Where abouts? A good local pro should get over to you. If on the South Shore, Norm Harvey of Independent Oil Service gets my nod.

    Nice that you have Gortons!
  • Looks like a

    decent installation. The header 45, while not usual, should not be a factor in what you describe. Some notes & ideas.

    1. Weil specifies the height of the casting line of the McDonnell 61 @ 1 1/2" above bottom gage glass nut. Lower the 61. Its present location is where a float operated LWCO/feeder would be located. Not a fan of electric feeders on commercial boilers. Where is the back-up LWCO?

    2. Weil shows the pressuretrol/gage in the "G" Tapping. That is where it is. They spec a close nipple between the turned down 90 & the turned up tee. Removing the existing 1/2" by 2" nipple, & replacing w/ a close, will get the manifold up 1".

    Don't like that location. We install controls & gages on pigtails in top crosses of control piping to LWCOs. Keeps them free of the crud floating around @ the water line.

    3. The 480 has a 1.33 piping & pick up factor. Your steam mains appear to be insulated. Try reducing the boiler input to take advantage of the reduced btu loss from the mains. The 201 CRD Carlin can be down-fired from the current 3.4 GPH (476 mbh). Try a 2.5 X 60 P nozzle @ the recommended 150# (428 mbh). 10% reduction in input should reduce, or eliminate, the short cycling. Was the burner set up w/ instruments? If not, please have it done.
  • Diar
    Diar Member Posts: 50

    My water line should be ~32", but due to the feeder/LWCO combo, it is about 33.5". I split the difference and the distance between the waterline 33" and the lowest return ( where the main vents are installed ) is 24". The other returns by the main vents are 25"/26" above the water line.

    I'm in Walpole, MA.
  • Diar
    Diar Member Posts: 50

    The casting line is 3" above the lowest part of the visible gauge glass or 3.5" above the lowest part of the gage glass nut. There's no backup LWCO, since I was told it wasn't code for this type of residential boiler install.

    I already had the boiler downfired 10%.
  • The water line is

    not where the LWCO should be located. The 80 has a 32 1/2" published water line. The top of the bottom gage glass nut is significantly below that. Add the 1 1/2" Weil wants to the 61 casting line. That is still below 32 1/2".

    If you had a float type water feeder, it would add water during the initial start up cycle while waiting for condensate return. After that first cycle, the standing water level would be a few inches above the feeder casting line. Slightly above the magic 32 1/2". The VXT Feeder on your boiler probably delays before feeding water when energized. By the time the VXT is ready to add water, the 61 is happy again. So the boiler water can't find its operating level. Open the hand valve & raise the water level an inch or two above the 61 casting line. Bet the low water problem goes away.

    The end of the mains don't quite meet the magic "A Dimension". Keeping the pressure down, as you are, should help w/ that.

    You're @ 90% of rated input. If the boiler still steams quickly, cuts on & off on pressure, the mains are hot all the way, & radiators heating, go for 80%. That's a 2.25 X 60 P @ 150# (384 mbh). The burner can do it. Watch the stack temp when setting up.

    Don't know Mass. Regs. But every local & national code I work w/ mandates a backup LWCO when the boiler has a rated input over 399 mbh.

    Good luck.
  • Diar
    Diar Member Posts: 50

    The water level when not in operation is always an inch above the casting line. The water level during full operation is at 1/2" above the bottom of the gauge glass, which is significantly below the casting line. One thing that doesn't make any sense to me is that I would expect the LWCO to trigger when the water level gets below the casting line. Is water level in the gauge glass accurate during operation?

    What's throwing me off is that there is a sign on the boiler that indicates that safe operation is when the water is 1/4 inch above the gauge glass. Therefore, I thought the LWCO was in the right place, since it seems to trigger when the operating water level falls before this threshold.

    In other words, I would expect that if we lowered the LWCO to the right place, which is 1.5" below were it currently is, that the water in the gauge glass could be empty without the LWCO triggering. Is this expected during operation?

    Sorry for asking so many questions, but I wouldn't want to move the LWCO to find out that I've done the wrong thing and put the boiler in danger of a low water condition.
  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
    First, install the gauge and controls properly

    then see how it does.

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  • Diar
    Diar Member Posts: 50

    My installer doesn't want to install the controls above the water line, since he indicates that the controls need to have a water seal, so that they are not damaged by steam.

    I assumed that the pigtails protected the controls when installed on the top of the boiler.

    Is this correct?

    Is there anything special that needs to be done to protect the controls ?

    Thanks for your help.
  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
    You are correct

    perhaps you need a more knowledgeable installer.

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