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New furnace started kicking after a season of quiet

Hi All,

I had the 1920s furnace replaced (after asbestos removal) three years ago, and while it took quite a lot of work from our heating guy, it has been fairly quiet... this season being the best yet!

Then about two weeks ago it started kicking, and despite a few cleaning and treatments (silicone based treatment) by our heating guy, it hasn't changed the kicking one bit. About 5 minutes into the heating cycle when cool or cold, it has a few big bangs, then a big gurgle. All of this heard throughout the heating system, but from the basement it seems to be from the return pipe near the furnace. I am rereading the Lost Art of Steam Heating to refresh my memory, but any tips would be appreciated!




  • kcoppkcopp Member Posts: 2,746
    So your...

    Boiler is hammering. Adding treatments to the boiler water as a general rule will not help. Skimming is the best treatment. Get any oils out of it that are in there.
  • Rich_LRich_L Member Posts: 59
    Anything Changed?

    You say it started about two weeks ago. Has anything changed or been changed in that time?
  • LiveFreeOrDieLiveFreeOrDie Member Posts: 8
    edited February 2014

    Treatment vs skimming.... we've done a lot of skimming in the past, and I think he tried skimming again this time as well, but I will verify.

    Changes... I did have to add some new water to it recently, and that was probably about the same time it started kicking..... if the system was new, including all the feeder pipe, would the new water have brought oils in with it? Enough to change things up?

    Edit: And I just watched the boiler a bit on startup, the water does tend to bounce a bit in the glass.... not that I watched it when it was quiet. It drops a good 3 inches.
  • kcoppkcopp Member Posts: 2,746
    If the near boiler.....

    piping is wrong then raising the water level will throw wet steam into the main and cause water hammer. Do you have any pictures?
  • LiveFreeOrDieLiveFreeOrDie Member Posts: 8

    I had attached them, but don't see them. 2nd try.
  • kcoppkcopp Member Posts: 2,746
    Near boiler....

    piping is not right. No equalizer....hence the water level in the glass is all over the place. And maybe the reason the water hammer.
  • BobCBobC Member Posts: 4,408
    Steam can be forgiving

    That boiler is not piped per the manufacturers recommendation and I'm a bit surprised it was once working well. If you compare the piping diagram in the installation manual to what you have it will become apparent that the installer was very innovative.

    The fact it was working tells me that something has changed (maybe something partially clogged), try lowering the water level a little bit and see if that changes the way it acts.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • LiveFreeOrDieLiveFreeOrDie Member Posts: 8
    Water level

    I had tried lowering the level, but no help.

    Thank you all for the replies. I do have the manuals for the boiler someplace, I will go compare the diagrams to the piping. At least the installer is a stand-up guy, so I have hope for a resolution if the piping is incorrect!
  • BobCBobC Member Posts: 4,408
    edited February 2014
    Old houses

    It's possible that some of the pipe slopes have changed because the house has settled, I know my 1918 house had issues after getting the boiler changed. Go over any horizontal pipe you can get to and make sure they all have some slope and that you don't have a dip somewhere (use a level, don't trust your eye) that might be pooling water.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • gcp13gcp13 Member Posts: 117

    Even with the incorrect pipping, if it was working

    Ok then started to make noise you should check the pressure

    Clean the pigtail and test the pressuretrol to see when it is

    Shutting the pressure climbs it can push the water out of the boiler into the return

    Especially without a proper equalizer.

    You can run the system as low as 1/2 lb. pressure

    Keep in mind the gauge may not work
  • LiveFreeOrDieLiveFreeOrDie Member Posts: 8

    I've attached another pictures, and I drew lines showing the pipes and connections. The majority of the piping is from the old installation, but the installer added the Hartford Loop.

    I see a path for the system to equalize pressure, are you guys saying it's not a correct "equalizer"?
  • gcp13gcp13 Member Posts: 117
    didn't see that

    didn't see that connection,that is acting as a equalizer

    but you have the first main taking off to the left and condensate

    dumping back down on top of steam as its trying to go higher

    into the 2nd main to the right that has that equalizer.

    did you check the pressure?

    if the noise starts early on before radiators start heating

    and building pressure, you probably do have some back pitched piping
  • A stand up guy

    I am sure he is, but may need some direction from you.

    In the manual for the boiler, there are specific instructions as to how the boiler is to be piped, and so go through those diagrams of piping, and see if you have the necessary piping layout, and DIAMETERS..--NBC
  • kcoppkcopp Member Posts: 2,746
    Here is the....

    install manual. see page 19

    They are pretty specific on piping just so, because the newer boilers have interior spacing that is much narrower than the old boilers.
  • Paul48Paul48 Member Posts: 4,234
    Carbon Monoxide

    Put a carbon monoxide detector in that basement.
  • Double DDouble D Member Posts: 160
    Great advice so far but.....

    The near boiler piping is not correct. When you say it's been fairly quiet. I assume you mean there has been noise in the past. The piping arrangement is not giving you dry steam. One piping correction has been pointed out for one of the mains. Although the path appears to give the effect of an equalizer, having the tee laying down feeding the main vs.standing vertical, is allowing water which would normally return to the boiler to enter the main. I also see the returns are grouped above the water line of the boiler. They must be grouped below the water line. The picture I attached to this reply is not the manufacturers diagram but it will give you an idea of what you should be seeing in your near boiler piping.
  • LiveFreeOrDieLiveFreeOrDie Member Posts: 8

    You mean from the flat/near downward slope of the exhaust piping? Yes, CO detector is down there, the chimney drafts like crazy and we have some good "vent holes" in the foundation/windows. Non living space too, otherwise I would have changed that up already.


  • LiveFreeOrDieLiveFreeOrDie Member Posts: 8
    Install manuals

    Yes, agree. I think I made an assumption based on my technical OCD sticking to details/recommendations on my job. I figured he would as well. I will go back through the install manuals and check all the details.
  • LiveFreeOrDieLiveFreeOrDie Member Posts: 8
    Piping Diagrams

    All, thank you for the great advice/review here. I will go back to the install manuals and double check the diameters and minimum distances.

    I'll get my visio out and diagram the current install and then outline modifications based on the install guide.

    I'll be back for another sanity check!

    Thanks all.
  • vaporvacvaporvac Member Posts: 1,512
    edited February 2014
    Spill Switch?

    It may be that I just can't enlarge the pictures enough, but I'm not seeing a Spill Switch on your swing draft. Mine didn't come with my boiler and it was only after careful reading that I realized I needed one. There are two different types depending if you have oil or a gas conversion burner. This is a MUST safety item. It senses temp changes in the flue and shuts off the burners if it drops which would most likely be due to a blockage.

    It's hard to tell the pitch of the exhaust venting pipes, but it seems minimal. It looks like you had plenty of height to place the damper and still get some pitch.

    BTW, you never said how well the old system worked and if these are only problems with this new install. P.S. I'm just a homeowner like yourself, but recently had a major install that I helped design and coordinate based on advice given here. It's working like a dream.
    Two-pipe Trane vaporvacuum system; 1466 edr
    Twinned, staged Slantfin TR50s piped into 4" header with Riello G400 burners; 240K lead, 200K lag Btus. Controlled by Taco Relay and Honeywell RTH6580WF
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