Why your washer smells like mildew in summer—and how to stop it

Summer humidity makes mildew inevitable—unless you act

Metro Vancouver's warm, humid summers create a perfect storm for washing machine odours. When you close the door after a load and trap moisture inside, combined with detergent residue and lint, mildew colonies thrive. Port Coquitlam's proximity to the Fraser River means even higher humidity levels in July and August. The problem isn't your washer—it's the environment it's sitting in.

The rubber seal is mildew's favourite hiding spot

That rubber gasket around your washer door does an excellent job keeping water inside. Unfortunately, it also traps moisture, lint, and soap film on both sides. Mildew loves this dark, damp crevice. After each load, spend 30 seconds wiping the gasket dry with an old cloth, paying special attention to the folds. Check inside the seal for visible black specks or a slimy texture—both signs of active mould growth.

Run a cleaning cycle once a month

The easiest way to kill mildew is to run a hot-water wash cycle with either white vinegar or a commercial washing machine cleaner. Pour two cups of white vinegar into the drum (not the dispenser) and run the hottest, longest cycle available. For front-loaders, use a commercial cleaner designed for the job—it's often more effective on stubborn buildup. Do this at least once a month during summer, and you'll eliminate odours before they settle in.

Leave the door open—really open

After every wash, prop the door fully open. Don't just crack it; swing it wide. Air circulation is your best defence against moisture. If your washer is in a basement or poorly ventilated laundry room, consider cracking a nearby window or running a fan for 15 minutes after washing. In Port Coquitlam, even summer air is fresher than trapped moisture.

Check your drain hose for clogs and kinks

A blocked or kinked drain hose prevents water from leaving the machine completely. That standing water becomes a mildew factory. Run your hand along the entire length of the hose (usually behind the washer) and straighten any bends. If water drains slowly from the tub, you may have a clog—disconnect the hose and flush it with a garden hose or plumbing snake. A properly draining washer is a dry washer.

Don't overload the detergent dispenser

Excess detergent residue feeds mildew growth. Use the amount recommended on your detergent bottle—usually less than you think. High-efficiency machines especially need less soap. Rinse out the dispenser drawer weekly and leave it open to dry between loads.

When to call for help

If you've cleaned the gasket, run multiple vinegar cycles, and the smell returns within days, you may have mould deeper in the drum or drain system. A professional can inspect the hidden surfaces and, if necessary, run a more aggressive cleaning cycle or replace a contaminated hose.