This shows that there is a trap in the washing machine drainHow do I hook up a washing machine drain line to this box?. How do I clean this? Other traps under sinks have threaded connectors so I can extricate crap. And somehow my drain hose is stuck in the box as gentle tugging will not disconnect it; is there a clip inside that somehow grips it? Coz' suddenly after 10 years, our Maytag front load washer is eschewing vapors into the garage and even into the kitchen sink and it seems needs a clean-out.
Neighbors suggested Tide washing Machine Cleanser; after 2 cycles the sewer smell is gone💁; of course we now know why, where, and when we get gassed 😄 Nonanoic acid, sulfophenyl ester http://www.pesticideinfo.org/Detail_Chemical.jsp?Rec_Id=PC36022 smells noxious, irritates the eyes but does the job😄 making sewer gas sweeter.
Sequel After a few days the stench returned. Nothing focuses like a spousal rebuke; I vaguely recollected that smell from 50 years ago-- the root cellar potato bin in spring. Aha! An aggregation of veggies -- where is this "clean-out" on this 1987 house? Outside the kitchen stucco wall is a 7 cm pipe plastered in, with a square nut cap about 30 cm off the ground. A non-metric nut! Dig out that 1 1\4 " flat wrench; apply some newtons; she won't budge! A neighbor had died 5 years ago and the heirs gave me his pipe wrench--a use for it! Use joules on the pipe wrench and the nut loosens without busting any stucco. I filled the 2 basins to the brim; dissolved 100 g of nonanoic acid sulfophenyl ester in each , opened the drains and turned on the garberator, with a 4 l bucket under the clean-out; the surfactant foamed and frothed and spat a big doggy bag of $!$&&. OK then do that agin! Still a bit more . Now we have sweet smelling sewers .