Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit

My riser and header aren't by the book, what effect will it have, etc?


My new boiler is a PB 64-08 399,000btu. The manual says 2 risers and a 4" header and he installed only 1 riser and existing 3" header. What will that do? My tenant says there was noises, maybe banging the other day.

Also, is it over sized for 4800 sq. foot 4 flat in Chicago?

and the close nipple at hartford loop was replaced with about 14" of piping.

Thanks in advance.


  • Jamie Hall
    Jamie Hall Member Posts: 17,690
    What this may do...

    is get you nice wet steam.  Which, in turn, may very likely give you water hammer problems.  It may also give you lower efficiencies than you should have.  It may give you poor or uneven heat.  You may even have problems with a tilted water line in the boiler.

    The long Hartford pipe may or may not give you water hammer problems.  Some do, some don't.

    The manual put out by the boiler manufacturer is usually the minimum arrangement which they are willing to live with.  One can install bigger and fancier, but one should never install less.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Steam Ports

    Basically you want to use all the steam exit ports that a boiler has. Using both ports would cut the steam velocity in half. If steam exits the boiler too quickly it carries a lot of water with it which, as Jamie mentioned, creates "wet steam". Having "wet steam" is not efficient as it limits the btus that can get on the "Steam Train" as Dan calls it. It also can cause water hammer in the system which is not desirable.

    You might want to take a look in the "Find a Professional" section at the top of this page.

    Skip the zipcode section and scroll down the page to "States" (the software has been out dated recently and the "zipcode" function apparently has some "bugs") Check there and see what steam pros are local to you. Chicago has some good ones.  Dave Bunnell ,"Boiler Pro". is in the Chicago area and he's "top notch"!

    - Rod
  • The Steam Whisperer (Formerly Boilerpro)
    edited January 2010
    You will probably have problems...

    if you don't have the minimum piping.  You may not get obvious problems (banging, squirting air vents), but its' likely you'll see alot more fuel use than necessary.  Also, a tipped waterline can wipe out the boiler in no time.  As to size, that sounds awfully big.  I have been working with a 13 unit condo at about 15,000 sq ft above grade (3 floors) and full basement and have the boiler turned down to 800,000 input and it is still filling the system with steam too fast. 

    Time to call the installer and insist it be repiped properly and I'd check if it meets basic sizing requirements by figuring out the capacity of the system. 

    The Steam Whisperer (Formerly Boilerpro)

    Chicago's Steam Heating Expert

    Noisy Radiators are a Cry for Help
  • chris9090
    chris9090 Member Posts: 2
    Thank you, an update.

    You guys were right, I saw it fire and so much water shot up the riser so that it started thd auto water filler and it was at the top of the glass already.

    The installer did oversize the only riser to 3" and height wise the header was much higher than the minimum 25" above the water line.

    About evenness of heat, it sounds like the speed of heating is unbalancing the horizontals as the close by front two unit building starts all heating in 5 minutes and the rear 2 units is taking 15 minutes to get to the main vent.

    Pitr at PTS heating was great but I had soot/CO in the tenants units and he couldn't start immediately so I went with a old heating guy that I now know doesn't know anything. He forgot the electronic damper and electronic ignition which I think will also give 2% more efficiency won't it?

    I also like the idea of turning down the gas control valve...I'll look into that. I also need to find a soap to skim the oil off with.

    Again, thanks .
This discussion has been closed.