Clogged drain or main line? How to tell

Probably a single clog

• Only one sink, tub or toilet is slow.
• Other fixtures drain normally.

Probably the main line

• Several fixtures are slow at once.
• The toilet gurgles when you run the sink or washer.
• Water comes up in the tub or a floor drain.
• There's a sewer smell inside.

Main line problems need a plumber with a drain machine or jetter. Stop running water until they arrive.