Most washers drain through a hose hooked into a vertical pipe called a standpipe, which drops to a trap and then a branch line that joins the rest of the drain system. In many Cypress homes the laundry is in the garage or an inside utility area, and the branch runs under the slab.
The washer's pump pushes water out faster than a sink ever drains. Lint, fabric fibers, pet hair and detergent residue settle in the trap and along the line. A partial restriction that would barely slow a sink is enough to make a standpipe overflow.
Where is the problem?
- IfOnly the standpipe overflows; other drains are fineThenThe laundry trap or branch is restricted.
- IfA nearby tub, shower or floor drain gurgles or fills when the washer drainsThenThe main line is likely restricted downstream.
- IfWater appears at a floor drain in the laundry areaThenOften a main-line warning; stop using water and check other fixtures.
- IfWater leaks from the hose or the back of the machineThenThe hose, connection or washer may be leaking rather than the drain.
What to do
- Stop the washer.Pause or cancel the cycle so the pump stops pushing water into the standpipe.
- Check the hose position.The hose should sit loosely in the standpipe, not jammed tightly into it and not pushed too far down.
- Clean up water promptly.Laundry areas often have flooring, cabinets or drywall nearby that can be damaged by standing water.
- Have the line cleared.A plumber can cable the standpipe trap and branch line. If the main line is involved, it will need to be cleared through the cleanout.
Preventing laundry drain clogs
Quick facts
- Main cause
- Lint and detergent residue
- Easiest prevention
- Lint catcher on the hose
- Main-line warning
- Other drains gurgle or fill when the washer drains
- Height and setup
- Standpipe and trap arrangement are set by plumbing code; ask a plumber about yours
Questions for the plumber
- Was the restriction in the trap, the branch line or the main line?
- Is the standpipe the right height and size for my washer?
- Would a lint filter be enough to prevent this, or is there buildup further down?
Common questions
Why does the standpipe overflow only near the end of the cycle?
The spin and drain portion pushes the most water at once, which is when a partly restricted line reaches its limit.
Can I just put the hose further down the pipe?
Pushing the hose too far down can cause other problems. It is better to clear the line and keep the hose positioned as the installation intends.
Is lint really enough to clog a drain?
Over many loads, yes. Lint combines with detergent residue and hair to form a dense mat in the trap and line.
General information for Cypress, not a quote or professional advice. In an emergency, call 911.