I live in an apartment in California where my building will undergo 3 weeks of re-plumbing. During this time the tenants will have no hot water, only warm/tepid. California law states that for a rental home to be habitable, there must be hot and cold running water. My question is: Are our apartments considered legally habitable with only tepid water?

Also, during the daytime the workman will be in each apartment (3-7 days) and there will be no running water all from 8AM to 5PM. The management will credit each apartment only $100 off the month's rent which we feel is very unfair considering the amount of disruption (including pet and parking displacement) for that length of time. Any help and insights will be greatly appreciated. Thanks!

Think of how much "disruption" you will have if you had to MOVE OUT for this work to be completed. Be thankful for the $100 which mgmt does NOT have to provide and "shower with a friend".

I have to agree with cville. Your landlord is trying to improve the rental property. It may be an inconvenience, but 3 weeks isn't a long time and any housing authority will side with the landlord. There aren't any laws that state the landlord has to give you any reduction in rent. Check your lease. There is usually a stipulation that allows him/her to do improvement work and give proper notice to the tenant. Usually a landlord will not put in money to update anything unless it is a necessity.