What it usually means
| Lint and soap in the standpipe or trap | The vertical pipe the washer hose hangs in, and the trap below it, clog with lint bound up in detergent. Overflows at the top of the pipe. |
|---|---|
| A partial blockage further down | The laundry line often joins the kitchen line. Grease from the kitchen narrows the pipe and the washer overwhelms it. |
| The hose pushed in too far | If the drain hose is jammed deep into the standpipe it can siphon or block the air gap. It should sit loosely, about a hand's length in. |
| A standpipe that is too short or too narrow | Older homes have 1.5-inch laundry drains built for older, slower machines. A modern washer can out-pump them even when clean. |
| The main line | If the basement toilet or floor drain bubbles or rises when the washer drains, see basement floor drain backing up. |
What to check yourself
- Stop the machine. Mop up, and check what is under the floor if the laundry is upstairs.
- Pull the drain hose out of the standpipe and look at how far it went in. Check the hose for kinks.
- Pour a bucket of water slowly down the standpipe. If it backs up straight away, the blockage is close. If it takes most of the bucket first, it is further down.
- If the washer drains into a laundry sink, clean the sink strainer and check the sink itself drains quickly.
- Fit a lint trap on the end of the drain hose if it empties into a sink.
Stop and call a plumber if
- It overflows on every load
- Another drain rises when the washer empties
- The laundry is on an upper floor and water has reached the ceiling below
- You can smell sewage at the standpipe
Call 1-800-604-0631, any hour.
What fixing it costs
Clearing a laundry drain is priced as a sink line: from $329. Those are regular-hours prices (9 to 5, Monday to Friday). Outside those hours every price is double. Each covers up to 2 hours on site, and the drain is tested in front of you before we leave.
If the pipe itself is undersized or the laundry box needs replacing, that is a separate job. See laundry box installation. It starts with an on-site estimate for $269, which comes off the price if you go ahead.
Questions people ask
Why did this start with a new washing machine?
High-efficiency machines use less water but pump it out harder. A drain that was only just coping with the old machine shows its limit with the new one.
Can I just seal the hose into the pipe so it cannot overflow?
No. The gap around the hose lets air in and stops the machine siphoning. Sealing it moves the water to the next weakest point, usually a floor drain or a sink.
Do you have a real example?
Yes. Pure Mechanical Group wrote up a Fraser Valley laundry drain call, from clearing the line to running a full test cycle: read the field report.