How to tell who’s at fault for a clog
A sewage clog is the tenant's responsibility only if the tenant clearly caused it — for example, by flushing items that do not belong in a toilet. Blockages from aging pipes, tree roots, or the main sewer line are the landlord's responsibility.
Landlords sometimes blame the tenant to avoid the cost of a repair, but the location and cause matter. A clog in a single fixture that a tenant caused is different from a backup in the shared main line, which no tenant controls. If the problem affects multiple drains, keeps recurring, or comes from outside the unit, it is almost certainly the landlord's.
Be cautious about accepting blame or agreeing to a repair bill before you understand the cause. If your landlord is pinning a building-plumbing problem on you, a free, confidential review can help you understand what is fair.
This is general information about California tenant rights, not legal advice. Every situation is different.