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New boiler sewage smell

angdell120angdell120 Member Posts: 7
edited March 23 in Gas Heating
We got a new boiler installed a month ago(x-2 series boiler) Every time it is on the basement stinks like sewage the company we used has no answers as to what is happening. One day after the install the boiler blew about 3 gallons of water on the floor. They said the PSI must have been too high. We just don’t know where to begin, any suggestions?


  • Jamie HallJamie Hall Member Posts: 10,382
    Hot water or steam? "The company said the PSI must have been too high". Indeed, if the relief valve opened. And there is no excuse for that -- getting the pressure right is part of the install, and if they didn't get that right one has to wonder what else they messed up.

    A sewage smell is not common from a boiler -- but if there is inadequate combustion air coming from anywhere else, and there is a dry trap in a floor drain (not at all unusual!) that would do it.

    Where to begin? Find a competent contractor. Where are you located? We may know someone...

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • DZoroDZoro Member Posts: 753
    post some pics of the install and boiler room.
  • angdell120angdell120 Member Posts: 7
    We are in New Britain, CT
  • angdell120angdell120 Member Posts: 7
  • JUGHNEJUGHNE Member Posts: 5,647
    Simplest guess is that when the burner fires the draft out the chimney is trying to pull air out of the basement.
    It could be pulling sewer gas out of either an open or loosely sealed pipe fitting or floor drain or washer drain which have dried up traps.
    How well are the sewer drain pipes to the right of the boiler sealed up?
  • JUGHNEJUGHNE Member Posts: 5,647
    For the relief valve opening problem, can you show us the expansion tank. Maybe an old one hanging up between the ceiling rafters. Show more piping above the boiler also, especially where the new connects to old pipes.
    Do you have cast iron radiators?
  • angdell120angdell120 Member Posts: 7
    We think ok, we don’t have any leaks. We don’t have any floor drains and the washing machines drains into a slop sink and no smell coming from that drain.
  • JUGHNEJUGHNE Member Posts: 5,647
    Drain lines can have something open that will not leak water out.
    Just that sewer gas can be pulled out when the boiler fires.

    You could open a window and see if the smell persists with free flowing combustion air coming into the basement.
  • EBEBRATT-EdEBEBRATT-Ed Member Posts: 5,712
    Cold be the "new boiler burning off smell" We seem to get a lot of those lately.

    We installed a Peerless oil fired this winter for the secretary where I work. She went crazy for 3-4 days while it burned off. Kept the windows open while she was home. Finally disapated
  • DZoroDZoro Member Posts: 753
    Closely inspect the cast iron drain pipes for cracks. Looks like there was a pipe going up from the cast with a poorly fitted cap. Check that cap, looks like it might be the wrong size for the pipe. The pipe looks like it might be copper and a iron size cap was used for it.
    Also does the slop sink have a drain trap under it?
  • angdell120angdell120 Member Posts: 7
    silly question, should we call a plumber to check out that cast iron pipe?

  • ratioratio Member Posts: 1,955
    The last bad boiler smell turned out to be a squirrel crisp on top of the boiler block, IIRC. If you can stand it, see if it's stronger in any one place in the basement.
  • angdell120angdell120 Member Posts: 7
    Within 24 hrs it started to smell, I don’t think an animal got in that quickly.
  • Intplm.Intplm. Member Posts: 732

    silly question, should we call a plumber to check out that cast iron pipe?

    Within 24 hrs it started to smell, I don’t think an animal got in that quickly.

    Animals can get in that quickly. So don't dismiss that possibility too quickly.

    @angdell120 Does the smell, smell like it is low tide near the rocks at Hammonasset? Then it is probably the drain pipes behind and to the right of the boiler. A few things do not look correct there. The rubber fittings, or fernco fittings that are installed on the cast iron drain pipes might need to be looked at. From the picture I can see that the drain plug clean out is against code.
    Do have the plumber come back. Have them look for the cause of the smell and install a proper clean out plug. That plug might be that cause of the smell.
  • ZmanZman Member Posts: 4,854
    Check the rubber "furnco's" on the sewer pipe in the against the wall. Does the room have a floor drain? Is it full of water?
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • EBEBRATT-EdEBEBRATT-Ed Member Posts: 5,712
    Start with the simple things first
  • HVACNUTHVACNUT Member Posts: 2,117
    That furnco cap looks like something I'd use to pump down the old boiler and purge zones.
    The force of the water from the pony pump could've opened a sweat joint. DWV copper?
    I would cut it below the tee and put a new furnco cap on.
  • angdell120angdell120 Member Posts: 7
    Thank you everyone, we have another plumber coming this week to check out the drain pipe & furnco. Hopefully get the smell of Hammonasset out of my house! 😣
  • Intplm.Intplm. Member Posts: 732
    Good luck @angdell120 please let use know how things turn out.
  • Erin Holohan HaskellErin Holohan Haskell Member, Moderator, Administrator Posts: 1,045
    Any updates, @angdell120 ?
  • plumbdevplumbdev Member Posts: 1
    Where is the low water cutoff?, expansion/compression tank? If the system has a lot of volume where is the bypass? is there condensation while firing?The water supply valve to the boiler is left on to the auto feed. Auto feed can over pressurize causing the relief to blow. Was there or is a there a leak in the system? did the contractor use stop leak to fix? If so, the stink can be from the relief of boiler water with stop leak in it.
  • meticulousmikemeticulousmike Member Posts: 11
    where is the expansion tank,air scoop and vent combo on the supply side on the boiler?why is the supply plumbed into the return and why isn't there a shutoff after the pressure reducing valve aka boiler fill valve?they should always be left in the auto fill position(lever down)..i always plumb the fill valve supply below a 90 as far down as i can with a shutoff below that where the tee goes into the pipe and plumb the scoop,tank,vent combo as far as it can fit on a horizontal pipe on the supply side leaving the boiler-this way when cold water is filling the boiler for the first time it has time to separate the air from the water by hitting that 90 and have time rising to the top of the pipe before the scoop takes over also when it's fully heated it separates even more to be vented out.
    drain cleaning, plumbing,heating and electrical repairs.
  • HotanCoolHotanCool Member Posts: 48
    Old house, old chimney! You sure it's a sewage smell? And they could have pipe differently to have more room on the left. But it's always about money.
  • psb75psb75 Member Posts: 87
    The black cast iron sewer pipe is too prominent a feature in your pictures to ignore as a possible source of the smell. And there are enough vagaries in the small sample we see that the rest of it may be suspect. Have it thoroughly inspected. The OTHER suspect is the SMALL black cast iron pipe in the picture--the gas supply pipe. Make sure that is checked out TOO. Leaking natural gas is scented to smell like methane--as a warning.
  • Charlie from wmassCharlie from wmass Member Posts: 4,063
    Can a photo of the washing machine drain get posted along with any other drains in the basement?
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • JackmartinJackmartin Member Posts: 132
    Okay firstly ,how did your installer get away with not installing a combustion make up for your boiler? This would not pass inspection in Canada. Your basement is so closely sealed that you are pulling sewer vent air into your living space and believe me that is not good for your health. Open a window and fire your appliance if the smell is not present than you know the boiler requires it’s own combustion air ,any appliance needs oxygen to burn and it will cause a negative in the room if this is not provided. I am looking at your pictures and I have to ask a silly question ,does this actually heat your home? The connections to your boiler are the smallest I have ever seen in this size of boiler. Where is the expansion tank and why did they mount your pump where it is impossible to service? Tell me did you get a tap and toilet plumber to install this boiler it certainly looks like it ,no experienced heating contractor would do an installation this way ,it is impossible to service. Once again the brains you had install this boiler put the pump on the wrong side ,tell us the company name and I will send him a copy of Pumping Away so maybe next time he can get it right I am so sick of looking at lousy work I will send it free, of course that being dependent on his attitude, if he thinks he knows everything there is really no point. One last comment and this is directed to your gas inspectors, do they really let gas piping go with no swing joints or combustion test after the appliance is installed? In the event your screwup had done a combustion test as he is supposed to ,he would have immediately seen the problem from his combustion analyizer. I hope the plumber you are contacting has the correct equipment to do your problem solving correctly, walking around and using your nose is just stupid. All the best Jack Winnipeg Canada
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