When rent may be reduced for the outage
You may be entitled to a reduction in rent for the time you went without heat, since paying full rent for a home you cannot safely heat can be unfair. Whether and how much depends on the situation.
When a rental is missing something as essential as working heat, the home is arguably worth less than what you are paying, and the law recognizes that idea. A rent reduction or credit for the affected time may be appropriate — but the specifics vary, and how you go about it matters. Simply deciding to pay less on your own carries real risks, including eviction.
The safer path is to document the dates you were without heat and discuss the right approach before acting. If you went without heat for a meaningful time, especially in cold weather, and want to understand a possible rent reduction, a free review can help.
This is general information about California tenant rights, not legal advice. Every situation is different.