The “new” sitcom “Working Class” (7 p.m., CMT) offers a variation on the “Hot in Cleveland” sitcom model, co-starring Betty White’s old co-star Ed Asner. “Working Class” is a rather terrible title for this show, which should be called “The Melissa Peterman Show,” because that’s basically what it is.

Peterman plays Carli, a beautiful, long-legged blonde with dazzling white teeth who appears to have retained her sassy sense of humor in the face of several failed marriages, three kids and no career. Carli’s brother, Nick (Steve Kazee), lives rent-free and apparently job-free. But he does provide some occasional babysitting and a wisecrack or two. Carli has three children, but they seem to be without distinct personalities.

Carli works at the local upscale grocer Parker’s Food, obviously modeled on Whole Foods and a good venue for Carli to contrast her meager fortunes with those who can drop three figures on fancy salads. Despite the show’s title, Carli has only sporadic moments of class envy. In one scene, she’s shocked to learn that a snooty customer has spent $30 on pastries to feed to her dog. But she discovers that only when she jokes that the size-0 woman is obviously not eating them herself.

Forget class consciousness. Carli’s essentially envious of women who have married better or who have fitter bodies. Unfortunately, Peterman’s overall prettiness makes her rather unbelievable in a role Roseanne Barr and Brett Butler (“Grace Under Fire”) pioneered more than two decades ago.

Ed Asner plays Hank, her neighbor and co-worker at the market, and he’s generally reduced to the kind of cranky old-man character he has been playing ever since Lou Grant told Mary Richards that he hated spunk. Hank’s dialogue includes references to Nixon and hippies, artifacts of a bygone era.

“Class” isn’t all that complicated. Look for the wrong guys to pursue Carli. She will let them down gently and sweetly and saucily while she carries a torch for her rich, handsome and spoken-for boss, Rob Parker (Patrick Fabian).

At a time when MTV flirts with child pornography laws and even “Hot in Cleveland” trades in drearily hackneyed smuttiness, there’s something refreshing about a sitcom that adheres to its PG-dom as a point of pride.

And there are probably harsher criticisms than stating that a sitcom’s star is simply too good-looking to be taken seriously as a beleaguered working mother.

Tonight’s other highlights

• Kenny Ortega guest stars on “Phineas and Ferb” (7 p.m., Disney).

• Ginnifer Goodwin (“Big Love”) and Amy Sedaris (“Strangers with Candy”) guest star on five new episodes of “SpongeBob SquarePants” (7 p.m., Nickelodeon), beginning tonight.

• After a trip to Massive Dynamic, Walter worries about Peter on “Fringe” (8 p.m., Fox).

• Cyber crime on “Hawaii Five-O” (9 p.m., CBS).

• The guys require some expert advice on “Gold Rush: Alaska” (9 p.m., Discovery).