Earthquakes and water heaters: the hazards are obvious. A shifting or toppling water heater poses such a major threat to your safety that California state law requires that these units be braced, anchored or strapped. Furthermore, the City of San Francisco stipulates that all water heaters that are moved or newly installed must be raised 18 inches off the ground.

When selling your home, you should be aware that you must provide certification that these state and local requirements have been met. For information on obtaining the proper certification, you can call the Department of Building Inspection's Plumbing Department at (415) 558-6054.

For water heater bracing instructions, see the following:

• The Homeowner’s Guide to Earthquake Safety produced by the Seismic Safety Commission of the State of California;
  
  
• Is Your Home Protected From Earthquake Disaster? A Homeowner’s Guide to Earthquake Retrofit prepared by the Institute for Business & Home Safety (IBHS); and
  
  
• Guidelines for Earthquake Bracing of Residential Water Heaters from the Department of General Services, Division of the State Architect.