In four weeks, on November 14, all of the remaining analogue channels will be switched off, leaving space for 20 Freeview channels.
Ford Ennals, chief executive of Digital UK, said: "This a big day for Whitehaven and for UK broadcasting. Switchover is a complex engineering project and I'm delighted that after many years of planning, the first stage went well.
"For thousands of households, today delivers a first taste of the additional choice and interactivity that digital television provides."
Nine out of 10 households in Whitehaven had digital TV last week, according to research conducted by GfK/NOP, whereas 75% had it on all their sets.
Ennals said: "Our priority today and in the coming weeks will be to remind late converters of the final deadline on November 14 and making sure plenty of help is available."
The digital switchover help scheme, established to provide help to people over 75 or with a disability, has so far received more than 2,000 requests for help with equipment and installation assistance for digital switchover.