Why the washer finds the problem first

During the drain and spin cycles a washing machine pushes many gallons into its standpipe in a few minutes. A kitchen sink never sends that much water at once. If the laundry drain or the main line is even partly restricted, the water backs up: over the top of the standpipe, out of a laundry sink, or up into a nearby shower or tub.

In many Fullerton homes the laundry sits in the garage or a hallway closet with the standpipe tied into a nearby drain. Lint, small socks and the residue from detergent build up in that short branch, while the main line downstream carries the washer's water together with everything else in the house.

Standpipe clog or main line?

  • IfWater spills only from the top of the standpipe and every other drain is fineThenThe laundry branch is likely restricted with lint or debris.
  • IfA tub, shower or toilet rises while the washer drainsThenThe main line is restricted. Stop doing laundry and get the main cleared.
  • IfThe overflow started after a new washer was installedThenCheck that the drain hose is not pushed too far into the standpipe and is not sealed airtight around it.
  • IfIt overflows only on the largest loadsThenA partial restriction is likely; it will get worse, so have the line checked.

What to check before calling

  1. Stop the machine.Pause or cancel the cycle and unplug the washer if water reached the floor around it.
  2. Look at the drain hose.Make sure it is not kinked behind the machine and is held loosely in the standpipe rather than jammed into it.
  3. Check for lint.Some washers have a pump filter near the front bottom. Clean it per the manual. A lint trap on a laundry sink drain also helps.
  4. Watch the other drains.Run a sink and flush a toilet. If either backs up into a tub or floor drain, treat it as a main-line problem.

Habits that help laundry drains

  • Use a lint catcher or mesh trap on the washer hose or laundry sink
  • Use the detergent amount the machine calls for; excess suds slow drainage
  • Empty pockets of tissues, coins and small items before washing
  • Wash heavily soiled or sandy items after shaking them out outdoors
  • Do not run several loads back to back if drains are already slow

Questions for the plumber

  1. Is the standpipe the right height and size for this washer?
  2. Is the laundry drain properly trapped and vented?
  3. Was the clog in the laundry branch or the main line?
  4. Would a camera inspection help explain repeated overflows?

Common questions

Why does my laundry sink fill when the washer drains?

If the washer drains into the sink, it may simply be draining faster than the sink can empty. If the sink drain is slow on its own too, it may be clogged.

Can a front-loader cause clogs?

Any washer can send lint and residue into the drain. Front-loaders use less water, which can make buildup in the branch more noticeable.

Is it safe to keep doing laundry if it only overflows a little?

It is better to stop. A small overflow means the line is restricted, and the next load could back up into a lower drain.

General information for Fullerton, not a quote or professional advice. In an emergency, call 911.