A dangerous AC unit is a different matter
An air conditioner that sparks, smokes, trips breakers, or is improperly installed can be a safety hazard the landlord must address — because keeping the unit's electrical system and provided equipment safe is part of the landlord's duty.
Even if cooling is not required, a dangerous AC unit is a different matter. Faulty wiring, an overloaded circuit, a window unit at risk of falling, or any sign of electrical burning are safety concerns that should be reported right away and treated as urgent.
A landlord is responsible for keeping provided equipment and the unit's electrical system safe. Do not keep using an AC that seems dangerous, and unplug it if you can do so safely. Document the problem and report it in writing. If your air conditioner poses a safety hazard and your landlord ignores it, a free, confidential review can help you understand your options.
This is general information about California tenant rights, not legal advice. Every situation is different.