@Anant Garg I'm a California real estate attorney, broker, and investor. I will provide you some general advice about California, but not your case specifically. While I respect the comments of those above, please realize that this is California, which has a large number of disclosures required by statute, case law, and contract. So, any comparisons to other states or how other states do it are frankly inapplicable. Yes, we Californians are crazy and we know it, but you can't beat 80 degrees in the "dead of winter."
I'm guessing from your post that you purchased an SFR, not a multi-family or condo. STATUTES: California statutes impose certain duties of disclosure in the Transfer Disclosure Statement, through which a seller can disclose any issues with the plumbing or any material defects. CASE LAW: California case law imposes a duty to disclose known material defects and a duty on agent to conduct a reasonable visual inspection of the property and report the findings of their inspection to the buyer. CONTRACT: Probably 95%+ of SFR purchase transactions in California utilize the California Association of Realtors Residential Purchase Agreement (RPA). The RPA imposes certain additional disclosures (in addition to statutory requirements) for a Seller Property Questionnaire or an Exempt Seller Disclosure. Either of these documents would include questions about the condition of the plumbing. Depending on the version, the RPA may have imposed a continuing duty of disclosure on the seller throughout the transaction.
If issues were disclosed to you during the transaction or if your property inspector reported these items to you, then the issues were disclosed or made known to you during the transaction when you could have negotiated a price reduction or credit or cancelled the transaction. However, if the seller did not disclose these issues or purposely covered up these issues, you may have recourse against the seller. You can check out this article to which I contributed several quotes for more information: www.realtor.com/advice/buy/sue-false-information-given-sellers/