A new area code is creating a new problem in San Francisco.
Dozens of intercoms used to reach someone in an office or apartment building are not working after the new 628 area code changed dialing rules. Older intercoms in the city are not programmed to dial a "1" and the area code -- so they are unable to connect to the building.
Most intercoms are programmed to dial just a seven-digit number.
"We actually thought our system would allow for 11 digits -- it wouldn't," said Marcella Bartolini, an apartment manager.
Apartment building managers are posting notes letting residents know why the phone is not ringing and residents are handing out cell phone numbers to delivery people.
Warman Security technicians like Kevin Reed are now in high demand as buildings work to replace or re-program intercom systems.
"We've got five technicians and they're all booked every day," Reed said.
Technicians said replacing a system starts at $2,500.