While I cannot give you legal advice in this forum, put everything in writing and give it to your landlord. If within a reasonable time things are not fixed, you should consult a landlord-tenant attorney regarding options.
Also, you can always ask the the landlord for a reduction in rent in lieu of fixing some issues.
THIS RESPONSE IS INTENDED TO CONVEY GENERAL INFORMATION ONLY. IT SHOULD NOT BE RELIED UPON OR TAKEN AS LEGAL ADVICE. FURTHER, THIS RESPONSE IS NOT INTENDED TO AND DOES NOT CREATE AN ATTORNEY-CLIENT RELATIONSHIP.
You are entitled to have a habitable property. You should definitely ask the landlord, in writing, to fix the plumbing. Give the LL a reasonable opportunity (all things being equal, 30 days is usually considered reasonable) to repair the problems that make the house uninhabitable. If the LL doesn't fix the problems in that time, you can make the repairs and deduct the cost from your rent. The landlord cannot evict you for complaining about habitability problems.
Items such as plumbing affect the habitability of a rental dwelling. (Civil Code section 1941.1) Nevertheless, you need to give the landlord written notice of the issues and a reasonable opportunity to correct these items before taking the next step of either demanding a rent reduction or using the "repair and deduct" remedy.
Frank W. Chen has been licensed to practice law in California since 1988. The information presented here is general in nature and is not intended, nor should be construed, as legal advice for a particular case. This posting does not create any attorney-client relationship with the author. For specific advice about your particular situation, consult with your own attorney.