Five Signs Your Main Sewer Line Needs Attention

Most homeowners notice drain problems one fixture at a time — a slow sink, a tub that takes a while to empty. But when the issue is in the main sewer line, the symptoms show up across the whole house. Catching them early can prevent a basement backup.

1. Multiple slow drains

If the kitchen sink, tub and basement floor drain are all slow at once, the restriction is likely in the shared line rather than in each fixture.

2. Gurgling toilets

Air being pushed back through the system as water struggles to pass a restriction often shows up as gurgling — particularly when another fixture is draining.

3. Water in the floor drain

Water appearing in a basement floor drain when you run the washing machine or flush an upstairs toilet is one of the clearest signs of a main line restriction.

4. Sewer odours

Persistent sewer smells indoors can point to a blockage, a dry trap or a damaged line. It's worth investigating rather than masking.

5. Recurring clogs

If a line keeps blocking after it's been cleared, something is causing it — roots, a sag in the pipe, or heavy build-up. A camera inspection is the best way to find out.

What to do next

Avoid chemical drain openers on a main line. Limit water use and book a professional cleaning, ideally with a camera check so you know the cause, not just the symptom.