Illustrative example
There has been no hot water for eleven days. The tenant has written twice and each time is told a plumber is coming.
Section 1941 obliges the landlord to repair dilapidations that render the dwelling untenantable, measured against the list in section 1941.1. It turns on notice and time: the duty to repair later dilapidations arises once the landlord knows of them, so the date of the first written report is the fact that starts every remedy the tenant has.
The landlord commits to a replacement within a fixed number of days and credits the rent for the days without hot water, and the tenant gives access on two named days.