New boiler sewage smell

JUGHNE

More WAG thoughts:
There was a thought years ago to run "grey" water from parts of the house drainage to the discharge of the septic tank, intending to not overload the septic tank. (Actually turns out to overload the leach field with detergent etc.)
There could be a pipe from the discharge of the septic tank, coming into the basement, that is hiding and not capped.
Possibly the boiler firing pulls those fumes inside.

BTW to have drain lines that low in the basement you must have a deeply buried tank or be located on a hill with almost a walk out basement type elevation. Here we usually see the sewer leave the basement about 3-4' off the floor and anything else goes into a lift pump/pit and is put into the sewer line. FWIW

Intplm.

angdell120 said:

Fred, nothing, I lifted it up. Not sure what it was for.

That might also be a cleanout access in the floor to your drainage system. Look and see if there is a pipe connected through the floor from that rectangular plate. If it is part of your drainage system? It is probably the source of the smell.
You can lift it, and you say it's nothing ?

angdell120

after hrs of sniffing I believe this morning we pinpointed the smell coming from the back of the furnace, from the pipe that leads to the chimney. Have the chimney guy coming next week, hopefully we can find the culprit of this nasty smell!

Intplm.

Best of luck.

Please post what is found.

Alan Welch

You posted a picture on October 5th of the flue damper in the closed position. When you turn up the thermostat , make sure it turns itself to the open position.

angdell120

@alan Welch, yes it does open.

mattmia2

I would have concerns about what might be going on with the plumbing behind that wood where the old cast iron wall hung sink was where the plastic laundry tub is now.

ClaudiaZ

Do you have an update on what the chimney sweep found? I’m having a very similar issue.