Alison and John Doherty, from Elderslie in Renfrewshire, scooped £14,671,343 in the Lotto Draw on Saturday 2 July.
They hid their ticket and waited two weeks until they returned from a planned holiday to have their win validated.
Just hours after being unveiled as a winner earlier this week, Mr Doherty, a self-employed plumber, darted off to complete a series of callouts.
Mr Doherty told The Sun: “I did a boiler breakdown straight after we went public.
“I’ve also been to three jobs this morning and I’ve got another after this.”
And the 52-year-old plumber doesn’t have any immediate plans to stop work, adding: “I’ll probably slow down a wee bit but I still want to keep doing it.
“I’d like to go down to four days a week and Alison is thinking three days.”
John, who launched JDPS Plumbers 30 years ago, said he enjoys being his own boss.
“That’s because it’s mine, if I was working for someone else I’d be away.”
The couplecelebrated their £14,671,343 win with a £45 Domino’s Hawaiian pizza meal and Alison bought a £300 Coach designer handbag.