What's going on
A washer drains into a standpipe, a vertical pipe in the wall or floor. Below the standpipe, a trap holds a small pool of water that keeps sewer gas from rising into your apartment. If the washer sits unused for a few weeks, that water can evaporate and let the smell through. If the drain hose sits loosely in an opening that isn't trapped, the smell has a direct path. Some people tape or stuff the hose into the standpipe to block the smell, but most manuals say not to seal it airtight, because that can cause siphoning.
Older buildings add other possibilities. Drain stacks and vents that are partly blocked or were altered over the years can pull water out of traps when other units drain, so the smell comes and goes. That's building plumbing, not your washer. A musty smell inside the drum, on the other hand, is usually residue in the machine and needs a different fix.
What you can check in five minutes
- Do a sniff test. Smell inside the empty drum, then at the standpipe opening. The stronger spot tells you where to focus.
- Pour a few quarts of water slowly down the standpipe to refill the trap.
- Check that the drain hose goes into the standpipe as far as the manual says, and no farther.
- Look for gaps or old tape around the hose and pipe openings.
- Notice whether the smell gets stronger when neighbors run water or flush.
- If the drum itself smells, run the washer's cleaning cycle as the manual describes.
Rent, own or co-op: who handles it?
Traps, stacks and vents are building plumbing. If the smell keeps coming back after you refill the trap, report it to the super, and mention any gurgling. In co-ops and condos, who takes care of drain lines depends on the building's documents, and the super or managing agent can tell you how yours works.
What a technician will look at
- •The drain hose, its connection to the pump, and any cracks
- •The drain pump and the residue around it
- •Inside the drum and around the door seal or under the rim, for buildup
- •How the hose is set up at the standpipe
- •Whether the source is outside the washer, which goes to a plumber
Andre's field note: When the drum smells clean and the standpipe smells bad, I'm usually the wrong person for the job, and I'll say so. Refilling a dried-out trap with water is about the easiest fix there is. If you've had water on the floor along with the smell, set up a leak sensor, and call us for washer service if a hose or pump turns out to be the cause.
Not sure where the smell starts? Call ProFix NYC at (929) 699-8358.