Conchata played cantankerous housekeeper Berta on the popular US sitcom, starring alongside Charlie Sheen, Jon Cryer, Angus T Jones and later Ashton Kutcher.
According to reports, she died on Monday as a result of complications from cardiac arrest.
Charlie Sheen, who was fired from Two And A Half Men in 2011, tweeted a picture of him and Conchata on set and described her as “an absolute sweetheart a consummate pro a genuine friend a shocking and painful loss”.
He added: “Berta, your housekeeping was a tad suspect, your ‘people’ keeping was perfect.”
Jon Cryer, who played Sheen’s bumbling on-screen brother, recalled meeting her on-set for the first time and said he was already a fan of her work.
He tweeted: “She was a beautiful human. Berta’s gruff exterior was an invention of the writers. Chatty’s warmth and vulnerability were her real strengths. I’m crying for the woman I’ll miss, and the joy she brought so many.”
Two And A Half Men co-creator Chuck Lorre said: “We called her Chatty. And we all loved her. Twelve years of highs and lows, and lots and lots of laughter. Through it all she was a rock. One of the greats. I was privileged to call her a friend.”
Lee Aronsohn, who created the show alongside Chuck Lorre, described Ferrell as a “warm, wonderful woman who was always a joy to be around on set”.
He added: “My heart goes out to her husband Arnie, who was *always* by her side.”
For her role as Berta, Conchata earned two Emmy nominations. Her film roles include the 1976 satirical comedy Network, Tim Burton’s Edward Scissorhands and Erin Brockovich, the 2000 biopic starring Julia Roberts.