Appliances not working? The heater doesn't work? Other habitability issues? Can you simply stop paying rent to "punish" the landlord? Not if you don't want to be evicted. However, you do have rights.
Whatever the problem is, remember this rule; "If it ain't in writing, it never happened!" In such disputes, you must give the landlord reasonable written notice. Send a letter, use a fax, or even email, and give the landlord a reasonable deadline, anywhere from a day to 10 days, depending on the urgency, to fix/repair the condition and that if the matter is not resolved, you will use "repair and deduct" provisions contained within California Civil Code 1942 and deduct the cost from your rent. Verbal demands and complaints will not protect you. You can also use the Code to vacate the premises prematurely, without penalty. CCC 1942(a) states:
"If within a reasonable time after written or oral notice to the landlord or his agent, as defined in subdivision (a) of Section 1962, of dilapidations rendering the premises untenantable which the landlord ought to repair, the landlord neglects to do so, the tenant may repair the same himself where the cost of such repairs does not require an expenditure more than one month's rent of the premises and deduct the expenses of such repairs from the rent when due, or the tenant may vacate the premises, in which case the tenant shall be discharged from further payment of rent, or performance of other conditions as of the date of vacating the premises. This remedy shall not be available to the tenant more than twice in any 12-month period."
If you choose to use the "repair and deduct" model, be sure to provide receipts of your expenses to the landlord, along with the net balance of the rent that is owed. Documentation is key. You have the burden of proof to show what was done, the cost of the repair such as receipts, photos, and the like. If you follow the law, inconvenience should be minimized.
The above is not meant to be a complete discussion of the law and any other applicable Code sections. I can only speak in generalities, not specifics. If you need further information, contact me by telephone or email.