Common Laundry Drain Problems
Laundry drains face unique challenges that other household drains don't experience. Understanding these issues helps you prevent them and know when professional help is needed.
Standpipe Overflow
The most dramatic laundry drain problem is water gushing out of the standpipe (the vertical pipe the washer hose drains into) during the spin cycle. This typically happens because:
- Drain can't keep up: Modern HE washers pump water out at 15-20 gallons per minute—faster than some drains can handle
- Partial clog: Lint and soap buildup restricts flow enough to cause backup during high-volume discharge
- Undersized standpipe: Older homes may have 1.5" standpipes; modern washers need 2" minimum
- Too-deep hose insertion: Washer hose inserted too far creates suction problems
Slow Draining
If your washer takes longer to drain or you hear gurgling during the drain cycle, buildup is restricting flow. This is the warning sign before complete clog or overflow—address it now while it's a simple fix.
Sewage Odour
Laundry rooms often develop unpleasant odours because:
- Dry P-trap: The water seal in the trap evaporates if rarely used, allowing sewer gas in
- Biofilm buildup: Bacteria feast on soap and lint residue, creating odour
- Venting issues: Improper venting allows sewer gas to escape through the standpipe
Important: If overflow occurs during every wash cycle, stop using the washer until the drain is cleared. Continued overflow can cause significant water damage to floors, subfloors, and adjacent rooms.
DIY Laundry Drain Cleaning
Many laundry drain issues can be resolved with these DIY methods:
Method 1: Hot Water Flush
- Remove washer hose from standpipe
- Slowly pour 2-3 gallons of boiling water down the standpipe
- Wait 15 minutes
- Repeat with another gallon
- This dissolves soap residue and softens lint blockages
Method 2: Drain Snake
- Insert drain snake into standpipe opening
- Push while rotating clockwise until you feel resistance
- Continue rotating to break up or hook debris
- Pull snake back, removing lint clumps
- Repeat until snake moves freely
- Flush with hot water
Method 3: Enzyme Treatment
Enzyme drain cleaners are ideal for laundry drains because they digest organic matter (lint, soap, fabric fibers) without damaging pipes:
- Pour enzyme cleaner into standpipe before bed
- Let sit overnight (or 8+ hours)
- Flush with hot water before using washer
- Repeat monthly for prevention
Pro Tip: Install an external lint trap on your washer discharge hose. These $10-$25 mesh filters catch lint before it enters the drain, dramatically reducing clog frequency. Clean the filter weekly.
When to Call a Professional
Some laundry drain issues require professional equipment and expertise:
- Repeated overflow despite cleaning: May indicate undersized or improperly installed drain
- DIY snaking didn't help: Clog is deeper in the main line
- Multiple drains affected: Laundry and nearby fixtures all slow—main line issue
- Persistent sewage smell: May need venting repair
- Water backing up into laundry tub: Shared drain line needs clearing
What Professionals Do
- Power drain snaking: Motor-driven cables clear stubborn buildup
- Hydro jetting: High-pressure water scours pipes clean
- Camera inspection: Identify root causes like pipe damage or improper installation
- Standpipe upgrade: Replace undersized 1.5" with proper 2" standpipe
Toronto Laundry Drain Cleaning Costs
DIY Costs
- External lint trap: $10-$25
- Drain snake: $15-$30
- Enzyme cleaner: $15-$25
Professional Service
- Standpipe snaking: $150-$200
- Power drain cleaning: $200-$300
- Main line cleaning: $250-$400
- Camera inspection: $150-$300
- Standpipe replacement: $200-$400
Prevention Tips
- Install external lint trap on discharge hose
- Clean washer's internal lint filter (if equipped)
- Run hot water down standpipe weekly
- Use enzyme drain cleaner monthly
- Don't insert washer hose more than 6" into standpipe
- Shake out heavily shedding items before washing
- Use appropriate amount of detergent (excess causes buildup)
Laundry Drain Overflowing?
We clear laundry drain clogs and fix overflow problems. Same-day service throughout Toronto and the GTA.
Call (647) 554-4356Frequently Asked Questions
Why does my washing machine drain overflow?
Washing machine drain overflow typically occurs when the standpipe is clogged with lint, soap residue, and fabric fibers. Modern high-efficiency washers pump water out faster than older machines, and if the drain can't keep up, water overflows. A partially blocked drain line, undersized standpipe, or improper installation can also cause overflow.
How often should I clean my laundry drain?
Clean your laundry drain every 3-6 months for prevention, or immediately if you notice slow draining or overflow. Run hot water down the standpipe weekly. Use enzyme cleaner monthly to break down soap and fabric residue. If you do heavy laundry loads or wash pet bedding frequently, clean more often.
Can I use drain cleaner in my washing machine drain?
Enzyme-based drain cleaners are safe and effective for laundry drains—they digest lint, soap, and organic matter without damaging pipes. Avoid caustic chemical drain cleaners like Drano, as the heat they generate can damage PVC standpipes. The best approach is mechanical cleaning with a drain snake for clogs, plus monthly enzyme treatment for prevention.
Why does my laundry drain smell like sewage?
Sewage smell from laundry drains usually indicates a dry P-trap. If the laundry area is seldom used, the trap water evaporates. Solution: pour water down the standpipe to refill the trap. If smell persists, the drain may have organic buildup, or there could be a venting issue.
How much does laundry drain cleaning cost in Toronto?
Professional laundry drain cleaning in Toronto costs $150-$300 depending on severity and access. Simple standpipe snaking runs $150-$200. If the clog extends into the main line, expect $200-$350. Camera inspection adds $150-$300 but helps diagnose recurring problems.
Do I need a lint trap for my washing machine drain?
While not required, an external lint trap for your washer discharge hose significantly reduces drain clogs. These $10-$25 mesh filters attach between the washer hose and standpipe, catching lint before it enters the drain. Clean weekly for best results.
Mike Thompson
Master Plumber & Drain Specialist
Mike has cleared countless laundry drain clogs across Toronto over 20+ years. He knows the unique challenges these drains face and the best solutions for keeping them flowing freely.