Legal Question in Real Estate Law in California

It will depend upon what's in the management contract. Mine is probably pretty typical; I reminded the property manager that this needed to be done, she said she knew that and had made arrangements for the installation, and on the next monthly statement the cost of acquiring and installing the detectors was deducted from my net rental income. It's a capital improvement and most property management agreements will call for the owner to bear these costs, but there could be exceptions where it is a triple-net lease or something unusual.

Usually it is the landlord's responsibility, as the "owner" of the property. http://law.onecle.com/california/health/13113.7.html