Septic Smell Mystery

[Emilee Hunter]

I live in an 8-year-old 3 story home. We are on a private well and septic and have a sump pump in the basement. Every summer when the weather gets hot we start getting septic smells in the house. Have had our tank pumped yet we still get the smell. I’ve read that it could be a dry trap so I go and run water in every drain and appliance and it doesn’t stop the smell. We can’t pinpoint the origin of the smell. Once it comes it seems to cover the house instantly and doesn’t seem stronger in one area than another. We do have forced air which could be carrying the smell to the whole home but we still can’t figure out where the smell is originating. This problem only happens in the summer when the weather gets hot. We don’t have any smell problems in Fall, Winter, or Spring. All the local plumbers are always willing to come “take a look” but not for less than $100 and actual services performed are always more than $500. I’m willing to have a plumber fix the problem but I’m worried we are going to have to spend $3000+ to find the answer. Does anyone have any ideas or suggestions?

 

[WorthFlorida]

Assuming your heating and cooling is the same air handler. When the when system is in cooling mode, (AC is on) the fan blows faster than when it is in heating mode. My theory is that when the AC is in, it is pulling air from a drain or vent into the home.

Where is the AC air handler located?
Is the same duct system used for heating?
Have you checked the plumbing venting that goes through the attic space to the roof? At times, a coupling is not glued, (maybe missed by an installer) and they come apart.
The sump pump, is it for septic use such as a washing machine or just for rain & ground water? If it is for septic the pit must be sealed and vented outdoors.
When you get the odors inside, can you smell anything outside around the home?

 

[Sponsor]

 

[WorthFlorida]

What you can do is block every single drain in the home. Of course if you can reproduce the odor every time or you get the odor all day long. Fill the sinks with some water with the drain plugged. Also tape over the bathtub overflow and any sink overflow. Any shower stalls cover the drain. The washing machine drain remove the washer drain hose and plugged the pipe with a wet rag. Are there any floor drains in the basement? If the odor subsides or goes away, you'll know at least the source.

 

[WorthFlorida]

Another source of odor can be your central air. I'm assuming you have central air and it requires maintenance at least once a year. It's very common for mold and algae to grow in the drip pan directly under the coil. There is an access cover you can remove. Check the condensate drain that it is clear. May have to flush if out. You might see a slime in the drip tray and mold on the coils. Usually coil cleaner that you can buy in hardware stores is good enough to use. You spray the coils down and let is sit for about 30 minutes. Then rinse with a garden hose, very lightly. Some only need the AC to run and the condensate will self rinse the coils. I'll use a shop vac to suck up the slime as I rinse the drip tray.

 

[Chucky_ott]

Google "dirty sock syndrome".

 

[WorthFlorida]

Google "dirty sock syndrome".

never heard that term but this is most likely the cause.

 

[Jeff H Young]

another somewhat common problem are condensates improperly connected to waste system either untraped or improperly. allowing stink to enter HVAC