Who repairs a provided garbage disposal
If a garbage disposal came with the rental, the landlord is generally responsible for repairing or replacing it when it breaks through normal use, since it is part of the plumbing and appliances provided with the unit.
A disposal that fails on its own is usually the landlord's to fix, like other provided fixtures. A tenant might be responsible if the disposal broke because of misuse — for example, putting in items that jammed or damaged it. A jammed disposal can also back up the sink, so report it if it is affecting the plumbing.
Check your lease, but a landlord generally cannot ignore a provided fixture that has stopped working, especially if it is causing a drainage problem. If your landlord refuses to repair a broken disposal that came with your unit, a free review can help you understand your options.
This is general information about California tenant rights, not legal advice. Every situation is different.