When too little hot water is a violation
Hot water that runs out almost immediately, or never lasts long enough for normal use, can be a habitability problem — especially if it comes from an undersized or failing water heater the landlord has not addressed.
Having hot water for only a minute is not much better than having none, because you still cannot reasonably bathe or clean. Common causes include a broken or too-small water heater, sediment buildup, or a failing part — issues the landlord is responsible for repairing.
When you report the problem, describe how the hot water actually performs, not just that some comes out. "There is hot water for two minutes" tells the landlord more than "the hot water works." If it consistently fails to meet normal needs and the landlord ignores it, that can cross the line into a habitability issue, and a free review can help you understand your options.
This is general information about California tenant rights, not legal advice. Every situation is different.