New house with a backflow preventer — do I have to test it?

Yes— and you're in good company not knowing that. Backflow assemblies almost never come up during a home sale, so most new owners first learn about theirs when the annual notice letter shows up addressed to them.

The responsibility follows the property

Annual testing is the current owner's responsibility. It transferred to you at closing, along with the water account. The Water Bureau's compliance records are tied to the address, so the next reminder letter — and any enforcement for a missed test — comes to you, regardless of what the previous owner did or didn't do.

First, check where things stand

1. Dig through your closing documents and anything the sellers left — a recent test report means you may be covered until the next annual cycle.
2. Locate the assembly so you know what you have and where it is before winter (they can freeze and crack if unprotected).
3. If you can't find any test history, don't wait for a letter — schedule a test and start your own clean record.

If the first thing you got was a notice

That's the normal way new owners find out. The letter lists the assemblies on record and your deadline — walk through what to do when you get the notice. The test itself is quick and inexpensive: roughly $50–150 and 15–30 minutes.